ISOLATION OF BIS-INDOLE ALKALOIDS WITH ANTILEISHMANIAL AND ANTIBACTERIAL ACTIVITIES FROM PESCHIERA VAN HEURKII (SYN TABERNAEMONTANA VAN HEURKII)

Extracts from leaves and stem bark of Pesehiera van heurkii (Muell. Ar g.) L. Allorge (syn. Tabernaemontana van heurkii Muell. Arg., Apocyna ceae) have been assayed for antileishmanial and antibacterial activiti es. The activities were concentrated in the alkaloid fractions which y ielded 20 indole and bisindole alkaloids. The strongest leishmanicidal and antibacterial activities were observed with the dimeric alkaloids conodurine (1), N-demethylconodurine (= gabunine) (2), and conodurami ne (3). Weak toxicity towards macrophage host cells and strong activit y against the intracellular amastigote form of Leishmania were observe d for compounds 1 and 2. In vivo, 1 was less active than glucantime (= N-methylglucamine antimonate), the drug of reference, while 2 was dev oid of activity at 100 mg/kg.