Structure activity relationship of four tetrahydrocannabinols and the pharmacological activity of five semi-purified extracts of Cannabis sativa

The structure activity relationships of four tetrahydrocannabinols and the pharmacological activity of five semi-purified extracts from Cannabis sativa were studied using four biological methods: corneal areflexia in rabbits (Gayer test) and catatonia, decrease of motor activity and suppression of isolation-induced aggressiveness in mice. Modifications in the structure of pure, natural ⁹-THC rendered the resultant compounds inactive only when activity was measured by the Gayer test; by the other three methods the activity ranged from 1/5th to equal to the activity of pure ⁹-THC. It was concluded that of the methods employed, the Gayer test was the only useful procedure to measure ⁹-THC content in mixtures. This was confirmed by the relationship found between ⁹-THC content and activity using five semi-purified extracts.Read before the XX Annual Meeting of the Brazilean Society for the Advancement of Science. This research was partially supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).