MOLECULE

1,8-Menthadien-4-ol

1,8-Menthadien-4-ol or p-Mentha-1,8-dien-4-ol or Limonene-4-ol belongs to the class of organic compounds known as menthane monoterpenoids. These are monoterpenoids with a structure based on the o-, m-, or p-menthane backbone. P-menthane consists of the cyclohexane ring with a methyl group and a (2-methyl)-propyl group at the 1 and 4 ring position, respectively. The o- and m- menthanes are much rarer, and presumably arise by alkyl migration of p-menthanes. Monoterpenoids are terpenes that contain 10 carbon atoms and are comprised of two isoprene units. The biosynthesis of monoterpenes is known to occur mainly through the methyl-eritritol-phosphate (MEP) pathway in the plastids (PMID: 7640522). Geranyl diphosphate (GPP) is a key intermediate in the biosynthesis of cyclic monoterpenes. GPP undergoes several cyclization reactions to yield a diverse number of cyclic arrangements. 1,8-Menthadien-4-ol is an extremely weak basic (essentially neutral) compound (based on its pKa). It exists as a pale, clear liquid and has a peppery, spicy aroma. p-Mentha-1,8-dien-4-ol has been detected, but not quantified in, several different foods, such as blackcurrants, caraway, citrus, pepper (spice), and spearmints. This could make p-mentha-1,8-dien-4-ol a potential biomarker for the consumption of these foods. p-mentha-1,8-dien-4-ol is also used as a phermone for pine bark beetles. 1,8-Menthadien-4-ol is one of the terpenoids that present only in traces in cannabis plants (PMID: 6991645). There are more than 140 known terpenes in cannabis and the combination of these terepenoids produces the skunky, fruity odor characteristic of C. savita.