Two new cytotoxic furoquinoline alkaloids isolated from Aegle marmelos (Linn.) Correa.

Two new cytotoxic furoquinoline alkaloids were isolated from the leaves of Aegle marmelos (Linn.) Correa; one from the total alkaloidal fraction (acid/base shake-out method) of the CHCl extract and identified as 7,8-dihydroxy-4-hydrofuroquinoline and named trivially as Aegelbine-A. The other new alkaloid isolated from the pet. ether extract and identified as 4-hydro-7-hydroxy-8-prenyloxyfuroquinoline and named trivially as Aegelbine-B, together with a known alkaloid; aegeline and a known phenolic acid; ρ-hydroxybenzoic acid. The structures of all the isolated compounds were established based on 1D and 2D NMR spectroscopy and HR-ESI/MS. The cytotoxic activity of the isolated compounds was evaluated in vitro against HepG-2, PC3, A549 and MCF-7 cell lines. The obtained results revealed promising activity with structure-based relationship which is discussed briefly.