Sesquiterpene Chemistry

Sesquiterpenes are C₁₅ hydrocarbons composed of three isoprene units, forming a major class of secondary metabolites in cannabis and other plants. Unlike monoterpenes (C₁₀), sesquiterpenes exhibit greater molecular complexity and often lower volatility, contributing to cannabis aroma profiles with earthy, woody, and spicy character. Common sesquiterpenes in cannabis include β-caryophyllene, α-humulene, and β-myrcene derivatives. Breeders and analytical chemists study sesquiterpene ratios as phenotypic markers because these compounds are genetically stable within cultivars and persist through curing. Sesquiterpene profiles vary significantly across chemotypes and are influenced by both nuclear genetics and environmental stress conditions.

Breeders monitor sesquiterpene expression as a chemotypic descriptor independent of cannabinoid content, helping establish cultivar identity and consistency. Sesquiterpene-dominant profiles are often associated with specific landrace lineages and are used to verify genetic purity in breeding programs.