Constituents of the Cultivated Mulberry Tree

From extracts of root bark of the cultivated mulberry tree (a variety of Morus alba L.) three new isoprene-substituted flavanones, Kuwanon D, E and F were isolated. Their structures were shown to be I, II and III, respectively. Key Word Index Morus alba - Moraceae - Kuwanon D - Kuwanon E - Kuwanon F - Isoprenoid-flavanone 1 Part VI: Nomura, T., T. Fukai and J. Matsumoto: J. Heterocyclic Chem. 17 , 641 (1980). 2 Preliminary accounts of this work have been presented: Nomura, T., T. Fukai and M. Katayanagi: Heterocycles 9 , 745 (1978); T. Nomura and T. Fukai: Heterocycles 9 , 1295 (1978); 12 , 943 (1979).