Calycosin is an ''O''-methylated isoflavone. It can be isolated from ''

Astragalus membranaceus ''Astragalus propinquus'' (syn. ''Astragalus membranaceus'', commonly known as Mongolian milkvetch in English; 'Хунчир' in Mongolian; ''huáng qí'' (), ''běi qí'' () or ''huáng huā huáng qí'' (), in Mongolia, is a flowering plant ...

'' Bge. var. ''mongholicus'' and '' Trifolium pratense'' L. (red clover).

Biosynthesis

Isoflavone 3′-hydroxylase uses formononetin, NADPH, H⁺ and O₂ to produce calycosin, NADP⁺ and H₂O.

References

O-methylated isoflavones {{phenol-stub