NOVEL CYTOTOXIC, ALKYLATED HYDROQUINONES FROM LANNEA-WELWITSCHII

Two novel natural products, lanneaquinol(1) and 2'(R)-hydroxylanneaqui nol (2), were isolated from the organic extract of the plant Lannea we lwitschii (Hiern) Engl. Their structures were solved by spectroanalyti cal methods and confirmed by comparison to synthetic models. The absol ute configuration of 2 was determined by the modified Mosher method. B oth compounds exhibited modest cytotoxicity against the NCI panel of 6 0 human tumor cell lines. The structures of two isomeric 4,5-dihydroxy -5-alkyl-2-cyclohexenones (7 and 8), which appear to be biogenetic pre cursors of 1 and 2, were also elucidated.