Isoprenylated flavonoids kuwanon

About seventy kinds of new phenolic compounds could be isolated from Japanese cultivated mulberry tree (Morus alba, M. bombycis, and M, Ihou) and Chinese crude drug Sang-Bai-Pi (the root bark of Chinese mulberry tree). Most of them are isoprenylated flavonoids. Among them, kuwanon G (1) was the first isolation of the active substance exhibiting the hypotensive effect from the Japanese Morus alba root bark [9]. Furthermore, kuwanon G (1) and its isoprenylated derivative kuwanon H (2) [10] are considered to be formed through an enzymatic Diels-Alder type reaction of a chalcone and a dehydrokuwanon C or its... 

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