Constituents and Chemical Characteristics.

Marijuana contains more than 400 chemical compounds. The main psychoactive substance is generally believed to be delta-9-tetrahydrocannabinol (THC), but at least 60 other cannabinoids (C21-containing compounds) have been identified in the pyrolysis products. Delta-8-THC is similar in potency to delta-9-THC (hereafter referred to as THC), but is present in only small concentrations. Cannabinol and cannabadiol are the other major cannabinoids present. The former is slightly psychoactive, but not in the amounts delivered by smoking marijuana. The average content of THC in marijuana plants usually ranges from 0.3% to 4% based on the climate, soil and growing conditions, and handling after harvest, but values as high as 20% have been achieved in some preparations. THC is a resinous weak acid, pKa = 10.6, with a very high lipid solubility and very low aqueous solubility. It binds to glass, diffuses into plastic, and is photolabile and susceptible to heat, acid, and oxidation. The (-) enantiomer is up to 100 times more potent than the (+) enantiomer depending on the pharmacological test.19.