Bruceanic acids

Quassinoid glycosides named bruceantinoside (72) and the new bruceanic acids B (73), C (74), and D (75) were isolated from wood Brucea antitfysenterica [39-40], Bruceanic acid D (75) was cytotoxic against P-388 (ED50 0.77 pg/mL). 

From the correlated structures of 1, 86, and 22, it seems reasonable to assume that bruceantin (1) (ED5o=0.59 ig/ml) [1] might be converted to dehydrobruceantin (86) (EDso=1.0 (Xg/ml) [1] and 86 might further converted to bruceanic acid-A (22) (ED5o=4.16 fAg/ml) (the values in the parentheses are antitumor activity for KB cells) [12], Thus, on the basis of these data, the activity drops with degradation of the quassinoid. 

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