MeSH

structure in first source

Date introduced: August 27, 2015

Cyclic compounds that include two rings which share a single atom (usually a carbon). The simplest example of this type of compound is Spiro[2.2]pentane, which looks like a bow tie.

Compounds which contain two or more rings in their structure.

Year introduced: 2005(1974)

A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.

Year introduced: 1998

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.

Organic compounds composed exclusively of carbon and hydrogen forming a closed ring that may be either alicyclic or aromatic.

Year introduced: 1998

Organic compounds that primarily contain carbon and hydrogen atoms with the carbon atoms forming a linear or circular structure.

A class of heterocyclic compounds that include a two-ring fused structure. Both aromatic and non-aromatic ring structures are included in this category.

Year introduced: 1998

Cyclic compounds that include atoms other than carbon in their ring structure.

Multiple ring heterocyclic compounds containing two or more rings that share two atoms and one bond in common.

Year introduced: 2017