Macaranga schweinfurthii

In addition to schweinfurthin C (83), three geranylated stilbenes, schweinfurthins A, B and D (121-123), isolated from Macaranga schweinfurthii (Euphorbiaceae) represent hexahydroxanthene derivatives, which can be considered as substituted cyclized geranylstilbenes [53,72]. 

Prenyl substitution is a conventional derivatization style in stilbenes, exemplified by artoindonesianin N 29 immArtocarpus gomezianus [17]. The prenyl groups in stilbenes cyclize to form new derivatives. 4-Hydroxy-5 -methoxy-6",6"-dimethylpyran[2",3" 3, 4 ]stilbene 30, 3,5 -dimethoxy-4-hydroxy-6",6"-dimethylpyran[2",3" 3, 4 ]stilbene 31, and 3,4,5-trimethoxy-6",6"-dimethylpyran [2",3" 3, 4 ]stilbene 32, with dimethylchromene ring in their structures, have been obtained from Lonchocarpus utilis (Leguminosae) [18]. Furthermore, schweinfurthins A-C 33-35 from the leaves of Macaranga schweinfurthii (Euphorbiaceae) are typical samples of the prenylated stilbenes [19]. 

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