ABSENCE OF ALKALOIDS IN PSYCHOTRIA-CARTHAGENENSIS JACQ (RUBIACEAE)

Psychotria viridis and P. carthagenensis are often discussed in relati on to the hallucinogenic beverage Ayahuasca, used for religious, medic inal and social purposes. The significance of including Psychotria spe cies in this beverage has been understood on the basis of substantial amounts of tryptamine alkaloids detected on leaves of both P. viridis and P. carthagenensis. Nevertheless, there is a long lasting debate ov er the identification of which Psychotria species are actually traditi onally employed. We here report that a P. carthagenensis leaf ethanol extract was found to be devoid of alkaloids. The extract significantly decreased mice body temperature (350 and 500 mg/kg). Toxicity assessm ent revealed that the extract induced sedation and slight ptoses (75% of animals treated with 1000 mg/kg). Lethality was not observed within 48 h. The data indicate that P. carthagenensis does have bioactive co mpound(s), possibly active al the central nervous system, but unlikely to be tryptamine alkaloids as in the case of P. viridis. Therefore, i f P. carthagenensis is indeed used by ayahuasqueros, its chemical and pharmacological significance have yet to be elucidated.