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Substantial progress has been made since 1988 in the field of aporphinoid alkaloids, including aporphines sensu stricto and biogenetically related aporphinoids. This review supplements our earlier ones (102-105) by including data published since 1988, as well as by reporting several related aporphinoids

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The alkaloidal content of the leaves and the barks of stems and roots of Colubrina faralaotra, subspecies faralaotra, was studied. Twelve alkaloids o f aporphine and bisbenzylisoquinoline structure were isolated and identified. Three alkaloids were found in major amounts: nuciferine, limacine and a new alkaloid, faralaotrine. From the minor alkaloids, the epi-4-steporphine was isolated for the first time. Le contenu alcaloidiqtre des feuilles et des kcorces de tiges et de racines de Colubrina faralaotra .sous-espkce faralaotra (Rhamnackes) a kt& ktudik. Douze alcaloides, de structttre aporphinique et bisbenzylisoquinolkique, ont ktk isolks et identifiks; trois d'entre-eux sont majoritaires: la nucifkrine, la limacine et un alcaloide nouveau, la faralaotrine. Parmi les alcaloides mineurs, l'kpi-4-stkporphine a ktk isolbe pour la premi2re fois. Le Colubrina faralaotra (H. PERRIER) R. CAPURON, SOUS espkce (ssp.) faralaotray est une Rhamnacte arborescente de Madagascar. La description complkte des Colubrina malgaches a Ct C donnCe par CAPURON (1965). Le genre Colubrina groupe une vingtaine d'espkces des rtgions tropicales et subtropicales. Les Colubrina malgaches sont des arbrisseaux, des arbustes (parfois grimpants) ou des arbres pouvant atteindre de grandes dimensions. Cinq espi-ces se difftrencient: C. asiatica, C. faralaotra, C. decipiens, C. alluaudi et C. htrmberti. Le Colubrina faralaotra est un arbre A Ccorce lisse, ne dkpassant pas une vingtaine de mttres de hauteur et 0,50 m de diamktre. Les feuilles p6tiolCes, de 5 A 10 crn de long sur 3 A 5 crn de large, sont ovales. Les inflorescences de trois A vingt fleurs sont plus ou moins pubescentes. C'est une esptce variable, largement rCpartie sur I'ile de Madagascar; cette variabilitt intkresse la pubescence, la taille e t la forme des feuilles, le plus ou moins grand dtveloppement des inflorescences et le degr6 de pubescence du fruit.

As part of an ongoing collaborative effort to discover new antimalarial agents from natural sources, we have tested 53 bisbenzylisoquinoline alkaloids for cytotoxicity against cultured mammalian cells and for antiplasmodial activity against chloroquine-sensitive and chloroquine-resistant clones of Plasmodium falciparum. The isolates from Cyclea barbata, Stephania pierrei, Stephania erecta, Pachygone dasycarpa, Cyclea atjehensis, Hernandia peltata, Curare candicans, Albertisia papuana, and Berberis valdiviana exhibited a wide range of biological potencies in antiplasmodial assays, and the majority exhibited some degree of cytotoxicity against human KB cells. More than half of the compounds tested, however, showed selective antiplasmodial activity, with >100-fold greater toxicity toward one or both of the P. falciparum clones, relative to cultured mammalian cells. The most selective alkaloids were (-)-cycleanine (40), (+)-cycleatjehine (50), (+)-cycleatjehenine (49), (+)-malekulatine (3), (-)-repandine (13), and (+)-temuconine (2). As a result of these studies, relationships between the structures, the stereochemistry, and the substitution patterns of these alkaloids and their in vitro antiplasmodial and cytotoxic activities are beginning to emerge.