PREPARATION AND ANTILEUKEMIC ACTIVITY OF CONGENERS OF TROPOLOISOQUINOLINE ALKALOIDS FROM ABUTA-CONCOLOR

Antileukemic tropoloisoquinoline alkaloids, pareirubine A (1) and gran dirubrine (2), at first have been isolated from Abuta concolor (Menisp ermaceae). Methylation of 1 and 2, existing in solution as a mixture o f tautomers gave the corresponding four methyl derivatives (3 - 6). Th ioimerubrine (7) and thioisoimerubrine (8) were prepared by the nucleo philic substitutions of the methoxyl groups at C-11 and -10, respectiv ely. Acetylation of 1 and 2 produced the corresponding mono-acetyl tau tomers (9 and 10). Antileukemic activity of these derived tropoloisoqu inoline alkaloids is also reported.