Abstract: | ![]() The heartwoods of Acacia giraffae and A. galpinii were selected from South African Acacias as representative of those with abnormally high and minimal tannin contents respectively. A. galpinii contains amongst other analogues, the first natural (+)-2,3-trans-3,4-trans-teracacidin (7,8,4′-trihydroxy-flavan-3,4-diol and novel 3-O-methyl-, 7,8-di-O-methyl- and 7,8,4′-tri-O-methylflavonol analogues. (−)-2,3-cis-3,4-cis-Melacacidin (7,8,3′,4′-tetrahydroxyflavan-3,4-diol) is also present, but tannins are absent. By contrast, from the large excess of leueofisetinidin tannins which characterizes the wood of A. giraffae, only (+)-catechin, (+)-2,3-trans-3,4-trans-leucofisetinidin (7,3′,4′,trihydroxyflavan-3,4-diol and all-trans-(+)-leueofisetinidin-(+)-catechin could be isolated. |