Cannabinoid biosynthesis Sample Clauses

Cannabinoid biosynthesis. Histochemical (▇▇▇▇▇ and ▇▇▇▇▇▇▇▇▇▇, 1976; ▇▇▇▇▇ et al., 1988), immunochemical (▇▇▇ and ▇▇▇▇▇▇▇▇, 1997) and chemical (▇▇▇▇▇▇ et al., 1981) studies have confirmed that glandular hairs are the main site of cannabinoid production, although they have also been detected in stem, pollen, seeds and roots by immunoassays (▇▇▇▇▇▇ and ▇▇▇▇▇▇▇, 1999) and chemical analysis (▇▇▇▇▇▇, 2004; ▇▇▇▇ et al., 2000). The precursors of cannabinoids are synthesized from 2 pathways, the polyketide pathway (▇▇▇▇▇▇▇ et al., 1975) and the deoxyxylulose phosphate/methyl-erythritol phosphate (DOXP/MEP) pathway (▇▇▇▇▇▇▇▇▇▇▇ et al., 2001) (Figure 3). From the polyketide pathway, olivetolic acid is derived and from the DOXP/MEP pathway, geranyl diphosphate (GPP) is derived. Both are condensed by the prenylase geranyl diphosphate:olivetolate geranyltransferase (GOT) (Fellermeier and ▇▇▇▇, 1998) to form cannabigerolic acid (CBGA), which is a common substrate for three oxydocyclases: Cannabidiolic acid synthase (▇▇▇▇▇ et al., 1996), Δ9-Tetrahydrocannabinolic acid synthase (▇▇▇▇▇ et al., 1995a) and Cannabichromenic acid synthase (▇▇▇▇▇▇▇▇ et al., 1998), forming cannabidiolic acid (CBDA), Δ9-tetrahydrocannabinolic acid (Δ9-THCA) and cannabichromenic acid (CBCA), respectively (▇▇▇▇▇▇▇▇ et al., 1999).