Biotransformation of 3,4-cyclocondensed coumarins by transgenic hairy roots of Polygonum multiflorum

Two new coumarin glycosides (5 and 6), together with one known compound (4), were biosynthesized by transgenic hairy roots of Polygonum multiflorum with three 3,4-cyclocondensed coumarins as substrates (1 to 3). Their structures were elucidated by physicochemical and extensive spectroscopic analyses. The results of this study demonstrated that the hairy roots of P. multiflorum have the abilities to glycosylate 3,4-cyclocondensed coumarins in a regio- and stereo-selective manner. Furthermore, the effects of three elicitors (salicylic acid, yeast extract and HgCl2) on the accumulation of the products were evaluated.   Key words: Polygonum multiflorum, transgenic hairy roots, biotransformation, 3,4-cyclocondensed coumarins.