Portal:Chemistry

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Introduction

Cannabinoid biosynthetic pathway showing formation of THCA, CBDA and CBCA from cannabigerolic acid (CBGA) via specific synthase enzymes

Cannabis chemistry examines the molecular structures, biosynthetic pathways and analytical methods for understanding cannabis phytochemistry. The plant produces over 140 cannabinoids, 200+ terpenes and numerous flavonoids and phenolic compounds, creating extraordinary chemical diversity that varies between regional populations and underlies differences in effects, aromas and traditional uses.

Cannabinoid biosynthesis begins with the polyketide pathway producing olivetolic acid, which combines with geranyl pyrophosphate to form cannabigerolic acid (CBGA), the "mother cannabinoid." Specific synthase enzymes then convert CBGA into THCA, CBDA or CBCA, which decarboxylate to their neutral forms (THC, CBD, CBC) through heat or aging. Terpene biosynthesis follows the MEP and MVA pathways, producing monoterpenes (myrcene, pinene, limonene) and sesquiterpenes (caryophyllene, humulene) that create regional "chemotypes" recognized by traditional farmers through scent alone.

Modern analytical chemistry employs HPLC, GC-MS and spectroscopic methods to quantify cannabinoids and profile terpenes, enabling documentation of regional chemical variation and authentication of traditional varieties. Understanding chemistry is essential for explaining why Himalayan charas differs from Moroccan kif, why some populations produce high THC while others maintain balanced cannabinoid ratios and how environmental factors influence chemical expression. This chemical knowledge complements genetic and botanical documentation of landrace diversity.