A new chromatographic method for the isolation of (−)-Δ9-(trans)-tetrahydrocannabinolic acid A

(−)-Δ9-(trans)-Tetrahydrocannabinolic acid A (THCA-A), which is the main cannabinoid in ripe plants and the biogenetk precursor of the psychoactive (−)-Δ9-(trans)-tetrahydrocannabinol, has been isolated from Cannabis sativa L. After extraction with petroleum ether and subsequent fractionation using alkali and diethyl ether, purification was performed by medium pressure liquid chromatography to yield an amorphous >99% pure powder. THCA-A was characterized by its chromatographic and spectroscopic data.