Title: steroid
Long Title: IUPAC Gold Book - steroid
DOI: 10.1351/goldbook.11259
Status: current

Definition
Naturally occurring compounds and synthetic analogues, based on the cyclopenta[a]phenanthrene carbon skeleton, partially or completely hydrogenated; there are usually methyl groups at \(\ce{C-10}\) and \(\ce{C-13}\), and often an alkyl group at \(\ce{C-17}\). By extension, one or more bond scissions, ring expansions, and/or ring contractions of the skeleton may have occurred.

Note
Natural steroids are derived in biogenesis from triterpenoids; they play important roles as hormones (sex hormones), membrane components (cholesterol) and emulsifying agents (bile acids).

Related Terms
- hormones: https://goldbook.iupac.org//terms/view/10810
- membrane: https://goldbook.iupac.org//terms/view/11555

Source
- PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 808 (https://doi.org/10.1515/pac-2015-1202)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/11259/html
- json: https://goldbook.iupac.org/terms/view/11259/json
- xml: https://goldbook.iupac.org/terms/view/11259/xml

Citation: Citation: 'steroid' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.11259
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-08-04T13:29:30+00:00