Term: terpenes https://doi.org/10.1351/goldbook.T06278 Definition: hydrocarbons of biological origin having carbon skeletons formally derived from isoprene [CH2=C(CH3)CH=CH2]. This class is subdivided into the C5 hemiterpenes, C10 monoterpenes, C15 sesquiterpenes, C20 diterpenes, C25 sesterterpenes, C30 triterpenes, C40 tetraterpenes (carotenoids) and C5n polyterpenes. Related Terms: 1) carotenes (http://doi.org/10.1351/goldbook.C00857). 2) carotenoids (http://doi.org/10.1351/goldbook.C00858). 3) isoprenoids (http://doi.org/10.1351/goldbook.I03306). 4) prenols (http://doi.org/10.1351/goldbook.P04816). 5) retinoids (http://doi.org/10.1351/goldbook.R05369). 6) steroids (http://doi.org/10.1351/goldbook.S06005). 7) terpenoids (http://doi.org/10.1351/goldbook.T06279). 8) hydrocarbons (http://doi.org/10.1351/goldbook.H02889). Source: PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1371 (https://doi.org/10.1351/pac199567081307) Citation: 'terpenes' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.T06278 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. 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.