Flavone production in transformed root cultures of Scutellaria baicalensisGeorgi

A flavone derivative 5,2'-dihydroxy-6,7,8,3'-tetramethoxyflavone identified by H-1-,C-13-NMR, FABMS, together with two known phenolics skullcapflavone I and acteoside (3), were isolated from Scutellaria baicalensis transforme d roots (clone C) into which the beta-glucuronidase gene had been integrate d by the infection with Agrobacterium rhizogenes A13. Another clone of tran sformed roots (clone W) was also induced by infection with A. rhizogenes AT CC 15834 (wild type). Both clones C and W, cultured in phytohormone-free BF liquid medium, produced 3 at a high content (maximum; clone C: 1.81% and c lone W: 2.96% of tissue dry weight) under the light and dark conditions. Th e contents of glucuronide-type flavonoids, such as baicalin and wogonin 7-O -glucuronide in clone W, were almost three limes higher than those in clone C. Compound 3, which was not detected in the intact plant roots, also accu mulated in leaf (0.23% dry weight) and root (0.68% dry weight) parts of in vitro cultured plantlets. (C) 1999 Elsevier Science Ltd. All rights reserve d.