Stemona collinsae

A series of stemofurans A-K (92-102) were isolated and identified from the methanolic extract of Stemona collinsae roots, many of which have the C-methylation of aromatic rings. The structural characteristics inferred that ring B on stemofurans A-K (92—102) was formed via the polyketide pathway always showing two oxygen substitutions in the meta position at C-3 and C-5 [57]. 

Accompanied by stemofurans A-K (92-102), the bibenzyls and stilbostemins A-F (132-137), were also isolated fi-om Stemona collinsae roots together with five known derivatives -the stilbenes pinosylvin and 4-methylpinosylvin and the dihydrophenanthrene stemanthrene D (359) [57]. Stilbostemin B (133) and D (135) have been previously isolated from Stemona tuberosa [75]. The consecutively designated stilbostemin G (138) was isolated from Stemona cf. pierrei [76]. It became apparent that the stilbenoids of Stemona genus can be characterized mainly by the C-methylation of aromatic rings and the formation of phenylbenzofurans. 

According to the TLC Cladosporium bioassay (bioautography), the four structural types of Stemona collinsae, stilbenes, bibenzyls,... 

Pacher T, Seger C, EngehneiCT D, Vajrodaya S, Hofer O, Greger H (2002) Antifungal stilbenoids frtnn Stemona collinsae. J Nat Prod 65 820-827... 

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