Definitions containing s10-membered

We've found 250 definitions:

Azulenes

Azulenes

Compounds based on a seven-membered ring fused to a five-membered ring. Heat can rearrange them to NAPHTHALENES which have two fused six-membered rings. They are similar to guaiazulenes which are SESQUITERPENES with a six-membered ring fused to a five-membered ring.

— U.S. National Library of Medicine

triazine

triazine

any of three isomeric compounds having three carbon and three nitrogen atoms in a six-membered ring

— Princeton's WordNet

indolizidine

indolizidine

A bicyclic heterocycle containing a six-membered ring fused to a five-membered ring, one of the bridging atoms being nitrogen; any derivative of this compound, especially several alkaloids

— Wiktionary

quinarene

quinarene

any mancude assembly of three carbocyclic rings having a six-membered quinonoid ring bonded (in the 1,4 positions) to two odd-membered rings whose size differs by two

— Wiktionary

Oxindole

Oxindole

Oxindole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. The compound's structure is based on the indoline structure but where a carbonyl is situated at the 2-position of the 5 membered ring.

— Freebase

Isoindoline

Isoindoline

Isoindoline is a heterocyclic organic compound with the molecular formula C8H9N. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. The compound's structure is similar to indoline except that the nitrogen atom is in the 2 position instead of the 1 position of the five-membered ring.

— Freebase

Carbazole

Carbazole

Carbazole is an aromatic heterocyclic organic compound. It has a tricyclic structure, consisting of two six-membered benzene rings fused on either side of a five-membered nitrogen-containing ring. The compound's structure is based on the indole structure but in which a second benzene ring is fused onto the five-membered ring at the 2–3 position of indole.

— Freebase

acetone peroxide

acetone peroxide

A cyclic organic peroxide; a mixture of mostly the trimer, (((CH)CO)), (TCAP or TATP), containing a nine-membered ring and the dimer, (((CH)CO)) containing a six-membered ring; it is a high explosive manufactured from acetone and hydrogen peroxide with the aid of sulphuric acid, and has been used by amateur bomb makers.

— Wiktionary

Cyclodextrin

Cyclodextrin

Cyclodextrins are a family of compounds made up of sugar molecules bound together in a ring. Cyclodextrins are produced from starch by means of enzymatic conversion. They are used in food, pharmaceutical, drug delivery, and chemical industries, as well as agriculture and environmental engineering. Hydroxypropyl Beta Cyclodextrin is the chief active compound found in Procter and Gamble's deodorizing product "Febreze" under the brand name "Clenzaire". Cyclodextrins are composed of 5 or more α-D-glucopyranoside units linked 1->4, as in amylose. The 5-membered macrocycle is not natural. Recently, the largest well-characterized cyclodextrin contains 32 1,4-anhydroglucopyranoside units, while as a poorly characterized mixture, at least 150-membered cyclic oligosaccharides are also known. Typical cyclodextrins contain a number of glucose monomers ranging from six to eight units in a ring, creating a cone shape: ⁕α -cyclodextrin: 6-membered sugar ring molecule ⁕β -cyclodextrin: 7-membered sugar ring molecule ⁕γ -cyclodextrin: 8-membered sugar ring molecule

— Freebase

Indoline

Indoline

Indoline is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. The compound is based on the indole structure, but the 2-3 bond is saturated. By oxidation/dehydrogenation it can be converted to indoles.

— Freebase

alpha-lactam

alpha-lactam

A lactam having a three-membered ring structure.

— Wiktionary

membered

membered

Having a specified number of members; e.g. a five-membered ring

— Wiktionary

oxetose

oxetose

Any monosaccharide having a configuration with a four-membered ring

— Wiktionary

oxirose

oxirose

Any monosaccharide having a configuration with a three-membered ring

— Wiktionary

septanose

septanose

Any monosaccharide having a configuration containing a seven-membered ring

— Wiktionary

cyclobutene

cyclobutene

A cycloalkene with a four-membered ring and one double bond.

— Wiktionary

polyquinane

polyquinane

Any polycyclic saturated hydrocarbon consisting of fused five-membered rings.

— Wiktionary

polyquinene

polyquinene

any polycyclic unsaturated hydrocarbon consisting of fused five-membered rings

— Wiktionary

octanose

octanose

Any monosaccharide having the configuration of an eight-membered ring

— Wiktionary

oxindole

oxindole

A bicyclic aromatic heterocycle containing a benzene ring fused with five-membered cyclic amide

— Wiktionary

thiepane

thiepane

A saturated seven-membered heterocycle having six carbon atoms and one sulfur atom

— Wiktionary

azocane

azocane

A saturated eight-membered heterocycle having seven carbon atoms and one nitrogen atom

— Wiktionary

oxocane

oxocane

A saturated eight-membered heterocycle having seven carbon atoms and one oxygen atom

— Wiktionary

oxepane

oxepane

A saturated seven-membered heterocycle having six carbon atoms and one oxygen atom

— Wiktionary

azepane

azepane

A saturated seven-membered heterocycle having six carbon atoms and one nitrogen atom

— Wiktionary

thiocane

thiocane

A saturated eight-membered heterocycle having seven carbon atoms and one sulfur atom

— Wiktionary

furanose

furanose

any cyclic hemiacetal form of a monosaccharide having a five-membered ring (the tetrahydrofuran skeleton)

— Wiktionary

pyranose

pyranose

any cyclic hemiacetal form of a monosaccharide having a six-membered ring (based on tetrahydropyran)

— Wiktionary

oxirane

oxirane

A three-membered heterocycle having two carbon atoms and one oxygen atom; ethylene oxide

— Wiktionary

Indole

Indole

Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is a common component of fragrances and the precursor to many pharmaceuticals. Compounds that contain an indole ring are called indoles. The amino acid tryptophan is an indole derivative and the precursor of the neurotransmitter serotonin.

— Freebase

tetrazole

tetrazole

A five-membered heterocycle having one carbon atom, four nitrogen atoms and two double bonds

— Wiktionary

chair conformation

chair conformation

the most stable chemical conformation of a six membered single bonded carbon ring like cyclohexane

— Wiktionary

beta-lactam

beta-lactam

A lactam having a four-membered ring structure; a structural element of many antibiotics such as penicillin.

— Wiktionary

triazolinone

triazolinone

A five-membered unsaturated heterocyclic ketone having three nitrogen atoms, one double bond and a carbonyl group

— Wiktionary

thiirane

thiirane

The saturated three-membered heterocycle containing two carbon atoms and one sulfur atom; ethylene sulfide

— Wiktionary

thiirene

thiirene

The unsaturated three-membered heterocycle containing two carbon atoms, one sulfur atom and a double bond.

— Wiktionary

azepine

azepine

An unsaturated seven-membered heterocycle having six carbon atoms, one nitrogen atom and three double bonds

— Wiktionary

oxepine

oxepine

An unsaturated seven-membered heterocycle having six carbon atoms, one oxygen atom and three double bonds

— Wiktionary

oxonine

oxonine

The unsaturated nine-membered heterocycle having eight carbon atoms, one oxygen atom and four double bonds

— Wiktionary

thiepine

thiepine

An unsaturated seven-membered heterocycle having six carbon atoms, one sulfur atom and three double bonds

— Wiktionary

thiocine

thiocine

An unsaturated eight-membered heterocycle having seven carbon atoms, one sulfur atom and three double bonds

— Wiktionary

azocine

azocine

An unsaturated eight-membered heterocycle having seven carbon atoms, one nitrogen atom and four double bonds

— Wiktionary

oxocine

oxocine

An unsaturated eight-membered heterocycle having seven carbon atoms, one oxygen atom and three double bonds

— Wiktionary

azete

azete

An unsaturated four-membered heterocycle containing three carbon atoms, one nitrogen atom and two double bonds

— Wiktionary

aziridine

aziridine

A three-membered heterocycle containing two methylene groups and an imine; the nitrogen equivalent of ethylene oxide.

— Wiktionary

diazepine

diazepine

A seven-membered unsaturated heterocycle having two nitrogen atoms and three double bonds; any derivative of this compound

— Wiktionary

tetrahydropyran

tetrahydropyran

a six-membered heterocyclic ether having five carbon atoms and one oxygen; the core structure of pyranose sugars

— Wiktionary

thiopyran

thiopyran

An unsaturated six-membered heterocycle consisting of five carbon atoms. one sulfur atom and two double bonds

— Wiktionary

halirenium

halirenium

Any reactive intermediate in the form of a three-membered unsaturated cyclic cation containing a positively charged halogen atom

— Wiktionary

phospholane

phospholane

A saturated, five-membered heterocycle having four carbon atoms and one phosphorus atom; any derivative of this compound

— Wiktionary

pyrazolone

pyrazolone

A five-membered unsaturated heterocyclic ketone (or lactam), derived from pyrazole, that is the basis of several pharmaceuticals

— Wiktionary

pyrazolidine

pyrazolidine

A saturated five-membered heterocycle containing three carbon atoms and two nitrogen atoms

— Wiktionary

pentazole

pentazole

The five-membered homocyclic compound containing five nitrogen atoms and two double bonds

— Wiktionary

piperazine

piperazine

A saturated heterocyclic compound, CHN, containing two nitrogen atoms in a six-membered ring; it is used as an anthelmintic.

— Wiktionary

oxetane

oxetane

a class of heterocyclic compounds having a four-membered ring containing 3 carbon atoms and 1 oxygen atom; the parent compound CHO

— Wiktionary

thiolane

thiolane

The five-membered saturated heterocycle having four carbon atoms and one sulfur atom; any derivative of this compound

— Wiktionary

dioxolane

dioxolane

Any heterocycle having a five-membered ring with three carbon atoms and two oxygen atoms

— Wiktionary

pyrazoline

pyrazoline

A five-membered heterocycle containing three carbon atoms, two adjacent nitrogen atoms and one double bond

— Wiktionary

tetrazine

tetrazine

Any six-membered heterocycle having two carbon atoms, four nitrogen atoms and three double bonds

— Wiktionary

silole

silole

A five-membered heterocycle having four carbon atoms, one silicon atom and two double bonds; it is analogous to cyclopentadiene

— Wiktionary

Azoles

Azoles

Five membered rings containing a NITROGEN atom.

— U.S. National Library of Medicine

diazecine

diazecine

An unsaturated ten-membered heterocycle having eight carbon atoms, two nitrogen atoms and five double bonds

— Wiktionary

dithiocane

dithiocane

Any of four isomeric, saturated, eight-membered heterocycles having six carbon atoms and two sulfur atoms

— Wiktionary

diazine

diazine

Any six-membered aromatic heterocycle containing four carbon atoms, two nitrogen atoms and three double bonds

— Wiktionary

dioxocane

dioxocane

Any of four isomeric, saturated, eight-membered heterocycles having six carbon atoms and two oxygen atoms

— Wiktionary

imidazoline

imidazoline

A five-membered heterocycle containing three carbon atoms, two non-adjacent nitrogen atoms and one double bond

— Wiktionary

oxirene

oxirene

The unsaturated three-membered heterocycle having two carbon atoms, one oxygen atom and one double bond

— Wiktionary

dithiazole

dithiazole

An unsaturated, five-membered heterocycle containing two sulfur atoms, one nitrogen atom and two double bonds

— Wiktionary

phosphepine

phosphepine

A seven-membered unsaturated heterocycle containing six carbon atoms, one phosphorus atom and three double bonds; any derivative of this compound

— Wiktionary

phosphole

phosphole

The unsaturated five-membered heterocycle having four carbon atoms, one phosphorus atom and two double bonds; an analogue of pyrrole

— Wiktionary

dioxirane

dioxirane

Any of a class of saturated heterocycles having a three-membered ring, one carbon atom and two oxygen atoms

— Wiktionary

diazinane

diazinane

A six-membered saturated heterocycle containing four carbon atoms and two nitrogen atoms; any derivative of this compound

— Wiktionary

thietane

thietane

Any of a class of saturated heterocycles having a four-membered ring, three carbon atoms and one sulfur atom

— Wiktionary

quinone

quinone

any of a class of aromatic compounds having two carbonyl functional groups in the same six-membered ring

— Wiktionary

triazepine

triazepine

A seven-membered unsaturated heterocycle having three nitrogen atoms and three double bonds; any derivative of this compound

— Wiktionary

molozonide

molozonide

Any of a class of unstable heterocycles containing three successive oxygen atoms in a five-membered ring; the 1,2,3-trioxolanes

— Wiktionary

trioxolane

trioxolane

A five-membered, saturated heterocycle, containing two carbon atoms and three oxygen atoms; any derivative of this compound

— Wiktionary

oxazaborolidine

oxazaborolidine

Any of a class of five-membered, saturated heterocycles containing two carbon atoms, a nitrogen, boron and oxygen atom

— Wiktionary

Azepines

Azepines

Seven membered heterocyclic rings containing a NITROGEN atom.

— U.S. National Library of Medicine

tetrazolinone

tetrazolinone

The five-membered, unsaturated heterocyclic ketone having four nitrogen atoms and one double bond opposite the carbonyl group

— Wiktionary

cycloheptatriene

cycloheptatriene

A cycloalkene having a seven-membered ring and three double bonds; removal of a hydride ion produces the aromatic tropylium ion

— Wiktionary

polyazulene

polyazulene

An electrically conducting polymer in which the repeat units are azulene molecules linked through the five-membered ring.

— Wiktionary

azadiphosphole

azadiphosphole

Any of several isomeric five-membered heterocycles having one nitrogen atom, two phosphorus atoms and two double bonds

— Wiktionary

cyclooctatetraene

cyclooctatetraene

A cycloalkene having an eight-membered ring and alternating single and double bonds; being nonplanar, it is not aromatic

— Wiktionary

oxasilolane

oxasilolane

A saturated four-membered heterocycle having two carbon atoms, one silicon and one oxygen atom; any of its derivatives

— Wiktionary

oxathiane

oxathiane

Any of three isomeric six-membered saturated heterocycles containing four carbon atoms, one oxygen and one sulfur atom

— Wiktionary

oxazine

oxazine

Any unsaturated six-membered heterocycle containing four carbon atoms, one oxygen, one nitrogen atom and two double bonds

— Wiktionary

Oxazines

Oxazines

Six-membered heterocycles containing an oxygen and a nitrogen.

— U.S. National Library of Medicine

pyrylium

pyrylium

A six-membered aromatic heterocyclic cation containing five carbon atoms and an oxygen atom that carries a positive charge; any derivative of this compound

— Wiktionary

acenaphthylene

acenaphthylene

A polycyclic aromatic hydrocarbon containing an unsaturated five-membered ring ortho- and peri-fused to the 1- and 9- positions of naphthalene.

— Wiktionary

aceanthrylene

aceanthrylene

A polycyclic aromatic hydrocarbon containing an unsaturated five-membered ring ortho- and peri-fused to the 1- and 9- positions of anthracene

— Wiktionary

azole

azole

Any of a class of five-membered unsaturated heterocycles having three carbon atoms, one nitrogen atom and two double bonds

— Wiktionary

acephenanthrene

acephenanthrene

A polycyclic aromatic hydrocarbon containing an unsaturated five-membered ring ortho- and peri-fused to the 1- and 9- positions of phenanthrene

— Wiktionary

oxadiazinane

oxadiazinane

A six-membered saturated heterocycle containing three carbon atoms, two nitrogen atoms and one oxygen atom; any derivative of this compound

— Wiktionary

imidazole

imidazole

A heterocyclic organic compound containing two nitrogen atoms separated by a carbon atom in a five-membered ring, called 1,3-diazole in w:IUPAC nomenclature.

— Wiktionary

pyrazole

pyrazole

A heterocyclic organic compound containing two nitrogen atoms next to each others in a five-membered ring, called 1,2-diazole in w:IUPAC nomenclature.

— Wiktionary

dihydrofuran

dihydrofuran

A five-membered, unsaturated heterocycle having four carbon atoms, one oxygen atom and one double bond; any derivative of this compound

— Wiktionary

azulene

azulene

A bicyclic aromatic hydrocarbon containing a five- and a seven-membered fused ring; it is a blue, oily liquid first obtained from the essential oil of wormwood.

— Wiktionary

trioxane

trioxane

Any saturated six-membered heterocycle having three carbon atoms and three oxygen atoms

— Wiktionary

dioxepine

dioxepine

A seven-membered heterocycle containing five carbon atoms, two oxygen atoms and two double bonds

— Wiktionary

Thietane

Thietane

Thietane is a heterocyclic compound containing a saturated four-membered ring with three carbon atoms and one sulfur atom.

— Freebase

oxathiolane

oxathiolane

A five-membered saturated heterocycle having a three carbon atoms, one oxygen atom and one sulfur atom

— Wiktionary

arsole

arsole

An unsaturated, five-membered heterocyclic compound of arsenic, CHAs; any substituted form of this compound

— Wiktionary

isothiazolidine

isothiazolidine

A saturated, five-membered heterocycle containing three carbon atoms and a sulfur and nitrogen atom in the 1,2 positions; any derivative of this compound

— Wiktionary

dihydrothiophene

dihydrothiophene

An unsaturated, five-membered heterocycle containing four carbon atoms, one sulfur atom and one double bond; any derivative of this compound

— Wiktionary

thiazolidine

thiazolidine

A saturated, five-membered heterocycle containing three carbon atoms and a sulfur and nitrogen atom in the 1,3 positions; any derivative of this compound

— Wiktionary

dithiin

dithiin

The unsaturated six-membered heterocycle containing four carbon atoms, two sulfur atoms and two double bonds

— Wiktionary

oxazolidinedione

oxazolidinedione

A five-membered saturated heterocyclic ketone having one nitrogen atom, one oxygen atom and two carbonyl groups

— Wiktionary

phosphazine

phosphazine

The six-membered aromatic heterocycle containing four carbon atoms, one nitrogen atom and one phosphorus atom

— Wiktionary

arsazine

arsazine

The six-membered aromatic heterocycle containing four carbon atoms, one nitrogen atom and one arsenic atom

— Wiktionary

dioxin

dioxin

the unsaturated six-membered heterocycle having four carbon atoms, two oxygen atoms and two double bonds

— Wiktionary

thiadiazepine

thiadiazepine

Any of several isomeric seven-membered, unsaturated heterocycles containing four carbon atoms, two nitrogen atoms, one sulfur atom and three double bonds

— Wiktionary

pyrone

pyrone

Any of a class of cyclic chemical compounds that contain an unsaturated six-membered ring with one oxygen atom and a ketone functional group.

— Wiktionary

morpholine

morpholine

A six membered, saturated heterocycle tetrahydro-1,4-oxazine containing four carbon atoms, one nitrogen and one oxygen atom; it has a number of industrial applications

— Wiktionary

diazirine

diazirine

The unsaturated heterocycle consisting of a three-membered ring containing one carbon atom and two nitrogen atoms connected by a double bond; it is isomeric with diazomethane

— Wiktionary

dioxane

dioxane

Any of a class of six-membered, saturated heterocycles having four carbon atoms and two oxygen atoms in the ring

— Wiktionary

oxaphosphole

oxaphosphole

The unsaturated five-membered heterocycle having three carbon atoms, one oxygen atom, one phosphorus atom and two double bonds.

— Wiktionary

oxathiine

oxathiine

The unsaturated six-membered heterocycle having four carbon atoms, one oxygen atom, one sulfur atom and two double bonds

— Wiktionary

oxadiazine

oxadiazine

An unsaturated six-membered heterocycle having three carbon atoms, one oxygen atom, two nitrogen atoms and two double bonds

— Wiktionary

diazaborolane

diazaborolane

A five-membered saturated heterocycle having two carbon atoms, two nitrogen atoms and a boron atom; any derivative of this compound

— Wiktionary

oxaphosphine

oxaphosphine

The six-membered unsaturated heterocycle containing four carbon atoms, one oxygen atom, one phosphorus atom and two double bonds

— Wiktionary

oxadiazepine

oxadiazepine

Any of several isomeric seven-membered, unsaturated heterocycles containing four carbon atoms, two nitrogen atoms, one oxygen atoms and three double bonds

— Wiktionary

diazaphospholane

diazaphospholane

A saturated, five-membered heterocycle having two carbon atoms, two nitrogen atoms and one phosphorus atom; any derivative of this compound

— Wiktionary

triazinane

triazinane

The six-membered aromatic heterocycle containing three carbon atoms and three nitrogen atoms arranged alternately; any derivative of this compound

— Wiktionary

oxoazetidine

oxoazetidine

A saturated, four-membered heterocycle containing two carbon atoms, one oxygen atom and one nitrogen atom; any derivative of this compound

— Wiktionary

pyrroline

pyrroline

Any of three isomeric monounsaturated heterocycles having a five-membered ring and one nitrogen atom CHN; any derivative of these compounds

— Wiktionary

oxepin

oxepin

The unsaturated seven-membered heterocycle containing six carbon atoms, one oxygen atom and three double bonds; it is tautomeric with the epoxide benzene oxide

— Wiktionary

Azete

Azete

Azete is a heterocyclic chemical compound consisting of an unsaturated four-membered ring with three carbon atoms and one nitrogen atom.

— Freebase

oxathiazolidine

oxathiazolidine

A five-membered, saturated heterocycle having two carbon atoms, and one each of nitrogen, sulfur and oxygen; any derivative of this compound

— Wiktionary

tetrahydrothiophene

tetrahydrothiophene

A saturated, five-membered heterocycle containing one atom of sulfur; it is added to natural gas to provide it with a detectable smell

— Wiktionary

thiatriazole

thiatriazole

Any of several isomeric five-membered heterocycles having one carbon atoms, three nitrogen atoms, one sulfur atom and two double bonds

— Wiktionary

oxazole

oxazole

A five-membered heterocycle having three carbon atoms, one oxygen atom, one nitrogen atom and two double bonds; the 1,3- isomer is aromatic

— Wiktionary

oxadiazole

oxadiazole

Any five-membered heterocycle having two carbon atoms, two nitrogen atoms, one oxygen atom, and two double bonds

— Wiktionary

iodoxol

iodoxol

A five-membered saturated heterocycle containing three carbon atoms, an oxygen atom and a hypervalent iodine atom; its derivatives (especially the benziodoxols) are used as pharmaceuticals etc

— Wiktionary

Pyridines

Pyridines

Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.

— U.S. National Library of Medicine

pyrrolidine

pyrrolidine

any of a class of heterocyclic amines having a saturated five-membered ring; especially the parent compound of this class, CHN

— Wiktionary

oxathiole

oxathiole

An unsaturated five-membered heterocycle having three carbon atoms, one oxygen atom, one sulfur atom and one double bond

— Wiktionary

cyclooctadiene

cyclooctadiene

Any of several isomers of a cycloalkene having an eight-membered ring and two double bonds, but especially 1,5-cyclooctadiene that is used as a ligand in organometallic chemistry

— Wiktionary

oxazepine

oxazepine

A seven-membered unsaturated heterocycle containing five carbon atoms, one nitrogen and one oxygen atom, and three double bonds; any derivative of this compound

— Wiktionary

carbon nanofoam

carbon nanofoam

an allotropic form of carbon consisting of a low-density, three-dimensional web of graphene plates, distorted by the inclusion of some seven-membered rings

— Wiktionary

thiatriazoline

thiatriazoline

Any of several isomeric five-membered heterocycles having one carbon atoms, three nitrogen atoms, one sulfur atom and one double bond

— Wiktionary

thiadiazole

thiadiazole

Any of several isomeric five-membered heterocycles having two carbon atoms, two nitrogen atoms, one sulfur atom and two double bonds

— Wiktionary

Azirines

Azirines

Unsaturated azacyclopropane compounds that are three-membered heterocycles of a nitrogen and two carbon atoms.

— U.S. National Library of Medicine

Azetidine

Azetidine

Azetidine is a heterocyclic organic compound. It belongs to the class of four membered rings and it contains a nitrogen atom.

— Freebase

thiazine

thiazine

A six-membered heterocycle containing four carbon atoms, one nitrogen and one sulfur atom, and two double bonds; many of its derivatives have important applications

— Wiktionary

thiazoline

thiazoline

An unsaturated heterocyclic compound containing a five-membered ring, one double bond, one nitrogen and one sulfur atom; any derivative of this compound

— Wiktionary

oxazoline

oxazoline

An unsaturated heterocyclic compound containing a five-membered ring, one double bond, one nitrogen and one oxygen atom; any derivative of this compound

— Wiktionary

dithietane

dithietane

Any of a class of heterocycle having a four-membered ring with two carbon atoms and two sulfur atoms

— Wiktionary

dioxetane

dioxetane

Any of a class of heterocycle having a four-membered ring with two carbon atoms and two oxygen atoms

— Wiktionary

thiadiazoline

thiadiazoline

Any of several isomeric five-membered heterocycles having two carbon atoms, two nitrogen atoms, one sulfur atom and one double bond

— Wiktionary

dithiane

dithiane

Any of three isomeric six-membered saturated heterocycles having four carbon atoms and two sulfur atoms; any derivative of these compounds

— Wiktionary

thiazolidinedione

thiazolidinedione

Any of a class of drugs, used to treat diabetes, containing a five-membered heterocyclic ring containing a nitrogen and a sulfur atom and two carbonyl groups.

— Wiktionary

thiadiazol

thiadiazol

A five-membered unsaturated heterocycle containing two carbon atoms, one sulfur atom, two nitrogen atoms and one double bond; any derivative of this compound

— Wiktionary

tetrahydropyridine

tetrahydropyridine

Any of three isomeric, six-membered, unsaturated heterocycles having five carbon atoms, one nitrogen atom and one double bond; any derivative of these compounds

— Wiktionary

dihydrooxazine

dihydrooxazine

Any six-membered unsaturated heterocycle containing four carbon atoms, one oxygen and one nitrogen atoms and one double bond

— Wiktionary

Azepane

Azepane

Azepane is a saturated heterocycle, containing one nitrogen atom in seven-membered ring. A well known azepane derivative is caprolactam.

— Freebase

oxathiazole

oxathiazole

The unsaturated five-membered heterocycle having two carbon atoms, one oxygen atom, one sulfur atom, one nitrogen atom and one double bond

— Wiktionary

carboline

carboline

Any of four isomeric tricyclic heterocycles consisting of a pyridine ring fused with the five-membered ring of an indole; many of their derivatives have biological action

— Wiktionary

isoxazoline

isoxazoline

A five-membered unsaturated heterocycle containing three carbon atoms, one nitrogen and oxygen atoms (adjacent) and a carbon-nitrogen double bond

— Wiktionary

Furans

Furans

Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.

— U.S. National Library of Medicine

iodoxole

iodoxole

The five-membered unsaturated heterocycle consisting of three carbon atoms, one oxygen atom, one hypervalent iodine atom and one double bond; any derivative of this compound

— Wiktionary

dioxaborolane

dioxaborolane

Any of several isomeric five-membered saturated heterocycles having two carbon atoms, one boron atom and two oxygen atoms; any derivative of this compound

— Wiktionary

triazole

triazole

either of two isomeric heterocyclic compounds having a five-membered ring with three nitrogen atoms and two double bonds in the ring; any organic derivative of these compounds

— Wiktionary

trithiane

trithiane

Any of three isomeric six-membered saturated heterocycles having three carbon atoms and three sulfur atoms; any derivative of these compounds

— Wiktionary

Tropolone

Tropolone

A seven-membered aromatic ring compound. It is structurally related to a number of naturally occurring antifungal compounds (ANTIFUNGAL AGENTS).

— U.S. National Library of Medicine

diazole

diazole

Either of two unsaturated heterocycles consisting of a five-membered ring containg three carbon atoms, two nitrogen atoms and two double bonds - namely pyrazole and imidazole

— Wiktionary

Pyrazolones

Pyrazolones

Compounds with a five-membered heterocyclic ring with two nitrogens and a keto OXYGEN. Some are inhibitors of TNF-ALPHA production.

— U.S. National Library of Medicine

triazoline

triazoline

An unsaturated five-membered heterocycle having two carbon atoms, three nitrogen atoms and one double bond (between two of the nitrogen atoms); any derivative of this compound

— Wiktionary

enediyne

enediyne

Any of a class of bacterial products characterized by nine- or ten-membered rings containing two triple bonds separated by a double bond, many of which are highly toxic to DNA and used as antitumour agents.

— Wiktionary

epoxide

epoxide

Any of a class of organic compound, cyclic ethers, having a three-membered ring; they are prepared by the selective oxidation of alkenes or by ring-closure of halohydrins; used to make plastics.

— Wiktionary

tetraoxane

tetraoxane

A six-membered saturated heterocycle having two carbon atoms and four oxygen atoms; especially the isomer having two peroxide groups (as in the acetone peroxide dimer)

— Wiktionary

tetrahydrofuran

tetrahydrofuran

a heterocyclic ether having a five-membered ring with four carbon atoms and one carbon; it is a colourless liquid with an ether-like smell, and is used as a polar solvent

— Wiktionary

Cyclooctane

Cyclooctane

Cyclooctane is a cycloalkane with the molecular formula (CH2)8. It is a simple colourless hydrocarbon, but it is often a reference compound for saturated eight-membered ring compounds in general.

— Freebase

rotane

rotane

Any of a class of hydrocarbons consisting of spiro-linked cyclopropane units only, but with a common [n]membered ring in the middle; they are named n-rotanes depending on the size of the inner ring

— Wiktionary

Oxocins

Oxocins

Compounds based on an 8-membered heterocyclic ring including an oxygen. They can be considered medium ring ethers.

— U.S. National Library of Medicine

quinolizine

quinolizine

Any of several isomeric non-aromatic bicyclic heterocycles, of formula CHN, having two six-membered rings with the nitrogen atom as one of the bridge atoms; any of very many known derivatives of these compounds

— Wiktionary

azlactone

azlactone

Any of a class of organic compounds formed by the cyclization of N-acyl-u03B1-amino acids; they are five-membered heterocycles containing both a nitrogen and oxygen atom in the ring, with the oxygen adjacent to a carbonyl.

— Wiktionary

Polyquinane

Polyquinane

A polyquinane and polyquinene is a saturated or unsaturated, respectively, polycyclic hydrocarbon consisting of fused five-membered rings. The simplest member is the bicyclic compound bicyclo[3.3.0]octane. Other members are triquinacene and dodecahedrane.

— Freebase

Aziridine

Aziridine

Aziridines are organic compounds containing the aziridine functional group, a three-membered heterocycle with one amine group and two methylene bridges. The parent compound is aziridine, with molecular formula C2H5N.

— Freebase

Cycloheptene

Cycloheptene

Cycloheptene is a 7-membered cycloalkene with a flash point of -6.7 °C. It is a raw material in organic chemistry and a monomer in polymer synthesis. Cycloheptene can exist as either the cis- or the trans-isomer.

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Diazole

Diazole

Diazole refers to either one of a pair of isomeric chemical compounds with molecular formula C3H4N2, having a five-membered ring consisting of three carbon atoms and two nitrogen atoms. The two isomers are: ⁕Imidazole ⁕Pyrazole

— Freebase

Atrane

Atrane

An Atrane is a tricyclic molecule with three five-membered rings. It has a transannular dative bond by a nitrogen atom, depicted as A. The name "atrane" was first proposed by Mikhail Grigorievich Voronkov. Various atranes are named depending on the central element, e.g. "silatrane"; "boratrane"; "phosphatrane", etc. It is also proposed that when Y = nitrogen, the prefix "aza" be inserted before element + "atrane" because atranes wherein E = silicon and Y = oxygen have been referred to as just "silatranes". Silatranes exhibit unusual properties as well as biological activity in which the coordination of nitrogen to silane plays an important role. Some derivatives such as phenylsilatrane are highly toxic. The transannular coordinate bond in atranes can be stretched and even broken by controlling their stereoelectronic properties. Proazaphosphatrane is a very strong non-ionic base and is utilized in various types of organic synthesis as an efficient catalyst. In 2000, Robert R. Holmes and his co-workers reported a new class of silatranes that contain three six-membered rings and revealed that these atranes have weaker nitrogen donor interaction in comparison with corresponding ones bearing three five-membered rings. The degree of the interaction depends mainly on the electronegativity effects of an exocyclic ligand.

— Freebase

Imidazoles

Imidazoles

Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).

— U.S. National Library of Medicine

Dioxirane

Dioxirane

A dioxirane is a molecule containing a three-membered ring composed of one carbon and two oxygens. Somewhat unstable, they are used in organic synthesis as oxidizing reagents. A dioxirane in common use is dimethyldioxirane, the dioxirane derived from acetone.

— Freebase

Pyrazolone

Pyrazolone

Pyrazolone, a five-membered-ring lactam, is a derivative of pyrazole that has an additional keto group. It has a molecular formula of C3H4N2O. There are two possible isomers: 3-pyrazolone and 5-pyrazolone. Examples of derivatives include: ⁕Ampyrone ⁕Metamizole ⁕Phenazone

— Freebase

Triazole

Triazole

Triazole refers to either one of a pair of isomeric chemical compounds with molecular formula C2H3N3, having a five-membered ring of two carbon atoms and three nitrogen atoms. The two isomers are: ⁕1,2,3-Triazole ⁕1,2,4-Triazole

— Freebase

Cyclopentanone

Cyclopentanone

Cyclopentanone is an organic compound with the formula (CH2)4CO. It is a colorless liquid with a peppermint-like odor. It is a cyclic ketone, structurally similar to cyclopentane, consisting of a five-membered ring containing a ketone functional group.

— Freebase

Isoindoles

Isoindoles

Benzopyrroles with the nitrogen at the number two carbon, in contrast to INDOLES which have the nitrogen adjacent to the six-membered ring.

— U.S. National Library of Medicine

Macrolides

Macrolides

A group of macrocyclic compounds formed by chain extension of multiple PROPIONATES and cyclized into a large (typically 12, 14, 16) membered lactone. They are often glycosylated. Many of them are ANTIBIOTICS.

— U.S. National Library of Medicine

Oxepins

Oxepins

Compounds based on a 7-membered heterocyclic ring including an oxygen. They can be considered a medium ring ether. A natural source is the MONTANOA plant genus. Some dibenzo-dioxepins, called depsidones, are found in GARCINIA plants.

— U.S. National Library of Medicine

β-Lactam

β-Lactam

A β-lactam ring, is a four-membered lactam. It is named as such, because the nitrogen atom is attached to the β-carbon relative to the carbonyl. The simplest β-lactam possible is 2-azetidinone.

— Freebase

Oxazoles

Oxazoles

Five-membered heterocyclic ring structures containing an oxygen in the 1-position and a nitrogen in the 3-position, in distinction from ISOXAZOLES where they are at the 1,2 positions.

— U.S. National Library of Medicine

Azocane

Azocane

Azocane is a heterocyclic organic compound with the molecular formula C7H15N. It consists of a saturated eight-membered ring having seven carbon atoms and one nitrogen atom attached to a single hydrogen atom. The fully unsaturated analog of azocane is azocine.

— Freebase

Boron trioxide

Boron trioxide

Boron trioxide is one of the oxides of boron. It is a nonlethal toxic white, glassy solid with the formula B2O3. It is almost always found as the vitreous form; however, it can be crystallized after extensive annealing. It is known as one of the most difficult compounds to crystallize. Glassy boron oxide is thought to be composed of boroxol rings which are six-membered rings composed of alternating 3-coordinate boron and 2-coordinate oxygen. This view is controversial, however, because no model has ever been made of glassy boron oxide of the correct density containing a large number of six-membered rings. The rings are thought to make a few BO3 triangles, but mostly link into ribbons and sheets. The crystalline form is exclusively composed of BO3 triangles. This trigonal, quartz-like network undergoes a coesite-like transformation to monoclinic β-B2O3 at several gigapascals.

— Freebase

Indoles

Indoles

Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.

— U.S. National Library of Medicine

Caprolactone

Caprolactone

ε-Caprolactone or simply caprolactone is a cyclic ester, a member of the lactone family, with a seven-membered ring with the formula (CH2)5CO2. This colorless liquid is miscible with most organic solvents. It is produced on a very large scale as a precursor to caprolactam.

— Freebase

Quinolizidines

Quinolizidines

Saturated quinolizines that are two fused six-membered rings with a nitrogen atom at the ring fusion. They are biosynthesized in PLANTS by cyclization of a LYSINE coupled to CADAVERINE. Many of them are naturally occurring ALKALOIDS.

— U.S. National Library of Medicine

Bufanolides

Bufanolides

Cyclopentanophenanthrenes with a 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. They are found in BUFONIDAE and often possess cardiotonic properties.

— U.S. National Library of Medicine

Muscone

Muscone

Muscone is an organic compound that is the primary contributor to the odor of musk. The chemical structure of muscone was first elucidated by Lavoslav Ružička. It consists of a 15-membered ring ketone with one methyl substituent in the 3-position. It is an oily liquid that is found naturally as the-enantiomer, but synthetic material is typically a racemate. It is very slightly soluble in water and miscible with alcohol. Natural muscone is obtained from musk, a glandular secretion of the musk deer, which has been used in perfumery and medicine for thousands of years. Since obtaining natural musk requires killing the endangered animal, nearly all muscone used in perfumery today is synthetic. It has the characteristic smell of being "Musky". One asymmetric synthesis of-muscone begins with commercially available-citronellal, and forms the 15-membered ring via ring-closing metathesis: Muscone is now produced synthetically for use in perfumes and for scenting consumer products.

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Cytochalasins

Cytochalasins

11- to 14-membered macrocyclic lactones with a fused isoindolone. Members with INDOLES attached at the C10 position are called chaetoglobosins. They are produced by various fungi. Some members interact with ACTIN and inhibit CYTOKINESIS.

— U.S. National Library of Medicine

Pyrimidines

Pyrimidines

A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They include several nucleic acid constituents (CYTOSINE; THYMINE; and URACIL) and form the basic structure of the barbiturates.

— U.S. National Library of Medicine

Aromatic hydrocarbon

Aromatic hydrocarbon

An aromatic hydrocarbon or arene is a hydrocarbon with alternating double and single bonds between carbon atoms forming rings. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent. The configuration of six carbon atoms in aromatic compounds is known as a benzene ring, after the simplest possible such hydrocarbon, benzene. Aromatic hydrocarbons can be monocyclic or polycyclic. Some non-benzene-based compounds called heteroarenes, which follows Hückel's rule, are also called as aromatic compounds. In these compounds, at least one carbon atom is replaced by one of the heteroatoms oxygen, nitrogen, or sulfur. Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes an oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one nitrogen atom.

— Freebase

Indolizidines

Indolizidines

Saturated indolizines that are fused six and five-membered rings with a nitrogen atom at the ring fusion. They are biosynthesized in PLANTS by cyclization of a LYSINE coupled to ACETYL COENZYME A. Many of them are naturally occurring ALKALOIDS.

— U.S. National Library of Medicine

Venturicidins

Venturicidins

Toxic substances isolated from various strains of Streptomyces. They are 20-membered macrolides that inhibit oxidative phosphorylation and mitochondrial ATPases. Venturicidins A and B are glycosides. Used mainly as tools in the study of mitochondrial function.

— U.S. National Library of Medicine

Thromboxane

Thromboxane

Thromboxane is a member of the family of lipids known as eicosanoids. The two major thromboxanes are thromboxane A2 and thromboxane B2. The distinguishing feature of thromboxanes is a 6-membered ether-containing ring. Thromboxane is named for its role in clot formation.

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Oxetane

Oxetane

Oxetane, or 1,3-propylene oxide, is an heterocyclic organic compound with the molecular formula C3H6O, having a four-membered ring with three carbon atoms and one oxygen atom. The term oxetane may also refer more generally to any organic compound containing an oxetane ring.

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Furanose

Furanose

A furanose is a collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle furan, but the furanose ring does not have double bonds.

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Aminoshikimic acid

Aminoshikimic acid

Aminoshikimic acid is a synthetic crystalline carboxylic acid. It is characterized by multiple stereogenic centers and functional groups arrayed around a six-membered carbocyclic ring. Aminoshikimic acid is also an alternative to shikimic acid as a starting material for the synthesis of neuraminidase inhibitors such as the antiinfluenza agent oseltamivir.

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Dioxolane

Dioxolane

Dioxolane is a heterocyclic acetal with the chemical formula (CH2)2O2CH2. It is related to tetrahydrofuran by interchange of one oxygen for a CH2 group. The corresponding saturated 6-membered C4O2 rings are called dioxanes. The isomeric 1,2-dioxolane is a peroxide. 1,3-Dioxolane is used as a solvent and as a comonomer in polyacetals.

— Freebase

Pyran

Pyran

In chemistry, pyran, or oxine, is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the location of the double bonds. In 2H-pyran, the saturated carbon is at position 2, whereas, in 4H-pyran, the saturated carbon is at position 4. 4H-Pyran was first isolated and characterized in 1962 via pyrolysis of 2-acetoxy-3,4-dihydro-2H-pyran. It was found too unstable, particularly in the presence of air. 4H-pyran easily disproportionates to the corresponding dihydropyran and the pyrylium ion, which is easily hydrolyzed in aqueous medium. Although the pyrans themselves have little significance in chemistry, many of their derivatives are important biological molecules, such as the pyranoflavonoids. The term pyran is also often applied to the saturated ring analog, which is more properly referred to as tetrahydropyran. In this context, the monosaccharides containing a six-membered ring system are known as pyranoses.

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Cupferron

Cupferron

Cupferron, the ammonium salt of N-nitroso-N-phenylhydroxylamine, is a common reagent for the complexation of metal ions. Its formula is NH4[C6H5NNO]. The anion binds to metal cations through the two oxygen atoms, forming five-membered chelate rings. Cupferron is prepared from phenylhydroxylamine and an NO+ source:

— Freebase

Tetrazine

Tetrazine

Tetrazine is an unstable compound that consists of a six-membered aromatic ring containing four nitrogen atoms with the molecular formula C2H2N4. The name tetrazine is used in the nomenclature of derivatives of this compound. Three core-ring isomers exist: 1,2,3,4-tetrazines, 1,2,3,5-tetrazines and 1,2,4,5-tetrazines.

— Freebase

Rotane

Rotane

The rotanes are a class of hydrocarbon consisting of spiro-linked cyclopropane units having a common n-membered ring in the middle. They are named [n]rotanes depending on the number of carbon atoms in the middle ring. The simplest of them, [3]rotane, is a branched triangulane.

— Freebase

Piperazine

Piperazine

Piperazine is an organic compound that consists of a six-membered ring containing two nitrogen atoms at opposite positions in the ring. Piperazine exists as small alkaline deliquescent crystals with a saline taste. The piperazines are a broad class of chemical compounds, many with important pharmacological properties, which contain a core piperazine functional group.

— Freebase

Tetrahydrothiophene

Tetrahydrothiophene

Tetrahydrothiophene is an organosulfur compound with the formula (CH2)4S. It consists of a five-membered ring containing four carbon atoms and a sulfur atom. It is the saturated analog of thiophene. It is a volatile, colorless liquid with an intensely unpleasant odor. It is also known as thiophane or THT.

— Freebase

Carbolines

Carbolines

A group of pyrido-indole compounds. Included are any points of fusion of pyridine with the five-membered ring of indole and any derivatives of these compounds. These are similar to CARBAZOLES which are benzo-indoles.

— U.S. National Library of Medicine

Diazepine

Diazepine

Diazepine is a seven-membered heterocyclic compound with two nitrogen atoms. Types include: ⁕1,2-diazepine ⁕1,3-diazepine ⁕1,4-diazepine When combined with a benzene ring, it is the basis of the benzodiazepine family of compounds. In these compounds the nitrogen atoms are at the 1 and 5 positions as, for example, in clobazam.

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Dithiothreitol

Dithiothreitol

Dithiothreitol is the common name for a small-molecule redox reagent known as Cleland's reagent. DTT's formula is C4H10O2S2 and the molecular structure of its reduced form is shown at the right; its oxidized form is a disulfide-bonded 6-membered ring. Its name derives from the four-carbon sugar, threose. DTT has an epimeric compound, dithioerythritol.

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Thiophene

Thiophene

Thiophene, also commonly called thiofuran, is a heterocyclic compound with the formula C4H4S. Consisting of a flat five-membered ring, it is aromatic as indicated by its extensive substitution reactions. Related to thiophene are benzothiophene and dibenzothiophene, containing the thiophene ring fused with one and two benzene rings, respectively. Compounds analogous to thiophene include furan and pyrrole.

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Oxepin

Oxepin

Oxepin is an oxygen-containing heterocycle consisting of a seven-membered ring with three double bonds. It exists as an equilibrium mixture with benzene oxide. The oxepin-benzene oxide system has fluctuating bonds in which the equilibrium can be shifted to one extreme or the other by suitable substituents. This compound is not aromatic.

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Macrolide Antibiotic

Macrolide Antibiotic

The macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. Macrolides belong to the polyketide class of natural products.

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Pyrazole

Pyrazole

Pyrazole is the organic compound with the formula C3H3N2H. It is a heterocycle characterized by a 5-membered ring of three carbon atoms and two adjacent nitrogen centres. Pyrazoles are also the class of compounds that have the ring C3N2 with adjacent nitrogen centres. Notable drug that is a pyrazole is Celebrex.

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Cardenolides

Cardenolides

C(23)-steroids with methyl groups at C-10 and C-13 and a five-membered lactone at C-17. They are aglycone constituents of CARDIAC GLYCOSIDES and must have at least one double bond in the molecule. The class includes cardadienolides and cardatrienolides. Members include DIGITOXIN and DIGOXIN and their derivatives and the STROPHANTHINS.

— U.S. National Library of Medicine

Oligomycins

Oligomycins

A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).

— U.S. National Library of Medicine

Penam

Penam

Penams are a subclass of the broader β-lactam family of antibiotics and related compounds. Penams contain a β-lactam ring fused to a 5-membered ring, where one of the atoms in the ring is a sulfur and the ring is fully saturated. Penicillin is a member of this family of compounds.

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Oxirene

Oxirene

Oxirene is a hypothesized heterocyclic chemical compound which contains an unsaturated three-membered ring containing two carbon atoms and one oxygen atom. As the configuration is extremely strained, no consensus exists whether the structure constitutes a molecule or whether it is merely a transition state. The substance is therefore mainly evaluated by molecular modeling techniques. Experimental indications exist that oxirene occurs in the Wolff rearrangement.

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Pyranose

Pyranose

Pyranose is a collective term for carbohydrates that have a chemical structure that includes a six-membered ring consisting of five carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle pyran, but the pyranose ring does not have double bonds. A pyranose in which the anomeric OH at C has been converted into an OR group is called a pyranoside.

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beta-Lactams

beta-Lactams

Four-membered cyclic AMIDES, best known for the PENICILLINS based on a bicyclo-thiazolidine, as well as the CEPHALOSPORINS based on a bicyclo-thiazine, and including monocyclic MONOBACTAMS. The BETA-LACTAMASES hydrolyze the beta lactam ring, accounting for BETA-LACTAM RESISTANCE of infective bacteria.

— U.S. National Library of Medicine

Pyrrole

Pyrrole

Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H4NH. It is a colourless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., N-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrins of heme, the chlorins, bacteriochlorins, chlorophyll, porphyrinogens.

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Avermectin

Avermectin

The avermectins are a series 16-membered macrocyclic lactone derivatives with potent anthelmintic and insecticidal properties. These naturally occurring compounds are generated as fermentation products by Streptomyces avermitilis, a soil actinomycete. Eight different avermectins were isolated in 4 pairs of homologue compounds, with a major and minor component usually in ratios of 80:20 to 90:10. Other anthelmintics derived from the avermectins include ivermectin, selamectin, doramectin and abamectin.

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Trioxane

Trioxane

Trioxane refers to any of three isomeric organic compounds composed of a six membered ring with three carbon atoms and three oxygen atoms, having the molecular formula C3H6O3. The three isomers are ⁕1,2,3-Trioxane, a hypothetical compound related to molozonide ⁕1,2,4-Trioxane, a hypothetical compound whose skeleton occurs as a structural element of some antimalarial agents. ⁕1,3,5-Trioxane, a trimer of formaldehyde used as fuel and in plastics manufacture.

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Oxazolidine

Oxazolidine

Oxazolidine is a five-membered ring compound consisting of three carbons, a nitrogen, and an oxygen. The oxygen and NH are the 1 and 3 positions, respectively. In oxazolidine derivatives, there is always a carbon between the oxygen and the nitrogen. All of the carbons in oxazolidines are reduced. Some of their derivatives, the oxazolidinediones, are used as anticonvulsants.

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Valinomycin

Valinomycin

A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.

— U.S. National Library of Medicine

Pyrone

Pyrone

Pyrones or pyranones are a class of cyclic chemical compounds. They contain an unsaturated six membered ring containing one oxygen atom and a ketone functional group. There are two isomers denoted as 2-pyrone and 4-pyrone. The 2-pyrone structure is found in nature as part of the coumarin ring system. 4-Pyrone is found in some natural chemical compounds such as chromone, maltol and kojic acid.

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Oxazoline

Oxazoline

Oxazoline is a five-membered heterocyclic organic compound containing one atom of oxygen and nitrogen. It exists between oxazole and oxazolidine in terms of saturation. It was first characterised in 1889 and was named in-line with the Hantzsch–Widman nomenclature. Compounds containing this ring are referred to as oxazolines or oxazolyls and have a variety of chemical uses; particularly as ligands in asymmetric catalysis and as protecting groups for carboxylic acids.

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Ovalene

Ovalene

Ovalene is a polycyclic aromatic hydrocarbon with the formula C32H14, which consists of ten peri-fused six-membered rings. It is very similar to coronene. Ovalene is a reddish-orange compound. It is sparingly soluble in solvents such as benzene, toluene, and dichloromethane. Its solutions have a green fluorescence under UV light. Ovalene has been shown to form in deep-sea hydrothermal vent areas and in the hydrocracking process of petroleum refining.

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Ladderane

Ladderane

In chemistry, a ladderane is an organic molecule containing two or more fused cyclobutane rings. The name arises from the resemblance of a series of fused cyclobutane rings to a ladder. Numerous synthetic approaches have been developed for the synthesis of ladderane compounds of various lengths. The mechanisms often involve [2 + 2] photocycloadditions, a useful reaction for creating strained 4-membered rings. Naturally occurring ladderanes have been identified as major components of the anammoxosome membrane of the anammox bacteria, Planctomycetes.

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Piperidine

Piperidine

Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic amine consists of a six-membered ring containing five methylene bridges and one amine bridge. It is a colorless fuming liquid with an odor described as ammoniacal, pepper-like; the name comes from the genus name Piper, which is the Latin word for pepper. Piperidine is a widely used building block and chemical reagent in the synthesis of organic compounds, including pharmaceuticals.

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Azirine

Azirine

Azirines are three membered heterocyclic unsaturated compounds containing a nitrogen atom and related to the saturated analogue aziridine. They are highly reactive yet have reported in a few natural products such as Dysidazirine. There are two isomers of azirine: 1H-azirines with a carbon-carbon double bond are not stable and rearrange to the tautomeric 2H-azirine, a compound with a carbon-nitrogen double bond. 2H-Azirines can be considered strained imines and are isolable.

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Isothiazole

Isothiazole

An isothiazole, or 1,2-thiazole, is a type of organic compound containing a five-membered aromatic ring that consists of three carbon atoms, one nitrogen atom, and one sulfur atom. Isothiazole is a member of a class of compounds known as azoles. In contrast to the isomeric thiazole, the two heteroatoms are in adjacent positions. The ring structure of isothiazole is incorporated into larger compounds with biological activity such as the pharmaceutical drugs ziprasidone and perospirone.

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Cyclooctene

Cyclooctene

Cyclooctene is a cycloalkene with an eight-membered ring. It is notable because it is the smallest cycloalkene that can exist as either the cis- or trans-isomer with the cis-isomer more common. Its most stable cis stereoisomer can adopt various conformations, the most stable one being shaped like a ribbon; its most stable trans-conformer is shaped like the 8-carbon equivalent chair conformation of cyclohexane.

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mesoionic compound

mesoionic compound

any of a class of compounds having five-membered ring heterocycles (or their benzo derivatives) which possess a sextet of u03C0-electrons in association with the atoms comprising the ring, but which cannot be represented by any one covalent or polar structure; typically the ring structure contains both positive and negative delocalised charges which cannot be associated with any one ring atom, and the negative charge can also be associated with a conjugated exocyclic atom (typically oxygen, sulfur, or nitrogen).

— Wiktionary

Tetrahydropyran

Tetrahydropyran

Tetrahydropyran is the organic compound consisting of a saturated six-membered ring containing five carbon atoms and one oxygen atom. The compound is a colourless volatile liquid, but is obscure. Derivatives of tetrahydropyran are, however, more common. Tetrahydropyranyl ethers derived from the reaction of alcohols and dihydropyran are common intermediates in organic synthesis. Furthermore, tetrahydropyran ring system, i.e. a five carbon atoms and an oxygen, is the core of pyranose sugars, such as glucose.

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Furan

Furan

Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen. The class of compounds containing such rings are also referred to as furans. Furan is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature. It is soluble in common organic solvents, including alcohol, ether and acetone, but is slightly soluble in water. It is toxic and may be carcinogenic. Furan is used as a starting point to other specialty chemicals.

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Tacrolimus

Tacrolimus

Tacrolimus is an immunosuppressive drug that is mainly used after allogeneic organ transplant to reduce the activity of the patient's immune system and so lower the risk of organ rejection. It is also used in a topical preparation in the treatment of atopic dermatitis, severe refractory uveitis after bone marrow transplants, exacerbations of minimal change disease, and the skin condition vitiligo. It is a 23-membered macrolide lactone discovered in 1984 from the fermentation broth of a Japanese soil sample that contained the bacteria Streptomyces tsukubaensis. It reduces interleukin-2 production by T-cells.

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Cardiac Glycosides

Cardiac Glycosides

Cyclopentanophenanthrenes with a 5- or 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. Plants they come from have long been used in congestive heart failure. They increase the force of cardiac contraction without significantly affecting other parameters, but are very toxic at larger doses. Their mechanism of action usually involves inhibition of the NA(+)-K(+)-EXCHANGING ATPASE and they are often used in cell biological studies for that purpose.

— U.S. National Library of Medicine

Pentazole

Pentazole

Pentazole is an aromatic chemical molecule consisting of a five-membered ring with all nitrogen atoms, one of which is bonded to a hydrogen atom. It has a molecular formula of HN5. Its SMILES structure is n1n[nH]nn1. Although strictly speaking a homocyclic, inorganic compound, pentazole has historically been classed as the last in a series of heterocyclic azole compounds containing one to five nitrogen atoms. This set contains pyrrole, imidazole, pyrazole, triazoles, tetrazoles, and pentazole. One can consider pentazole to be at the interface between inorganic and organic chemistry.

— Freebase

Quinazoline

Quinazoline

Quinazoline is a heterocyclic compound made up of two fused six-membered simple aromatic rings, a benzene ring and a pyrimidine ring. Its chemical formula is C8H6N2. Quinazoline is yellow solid. It is isomeric with other naphthyridines including quinoxaline, phthalazine and cinnoline. Derivatives of quinazoline are called quinazolines. Medicinally it has been used in various areas especially as an anti-malarial agent and in cancer treatment. One example of a compound containing the quinazoline structure is doxazosin mesylate. The ring system is typically prepared by heating 2-acylanilides in the presence of ammonia or amines.

— Freebase

Pyridazine

Pyridazine

Pyridazine is a heteroaromatic organic compound with the molecular formula C4H4N2, sometimes called 1,2-diazine. It contains a six-membered ring with two adjacent nitrogen atoms. It is a colorless liquid with a boiling point of 208 °C. Pyridazine has no household use. It is mainly used in research and industry as building block for more complex compounds. The pyridazine structure is found within a number of herbicides such as credazine, pyridafol and pyridate. It is also found within the structure of several pharmaceutical drugs such as cefozopran, cadralazine, minaprine, pipofezine, hydralazine, and cilazapril.

— Freebase

Mesoionic

Mesoionic

Mesoionic chemical compounds are dipolar five- or six- membered heterocyclic compounds in which both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be represented satisfactorily by any one mesomeric structure. The formal positive charge is associated with the ring atoms and the formal negative charge is associated either with ring atoms or an exocyclic nitrogen atom. Mesoionic compounds are a subclass of betaines. Examples are sydnones and sydnone imines, and münchnones.

— Freebase


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