Hydroxylation and glucoside conjugation in the microbial metabolism of the diterpene sclareol

1. The microbial metabolism of sclareol (1), a labdane diterpene ditertiary alcohol, was studied. Preliminary screening identified a number of microorganisms capable of metabolizing sclareol. 2. Preparative scale fermentation of growing cultures of Bacillus cereus UI-1477 resulted in the production of seven metabolites which have been characterized as 3 beta-hydroxysclareol (2), 2 alpha-hydroxysclareol (3), 18-hydroxysclareol (4), 2 alpha,18-dihydroxysclareol (6), 8 alpha,13 beta-dihydroxy-labd-14-en-3 beta-O-beta-D-glucoside (5), 8 alpha,13 beta-dihydroxy-labd-14-en-18-O-beta-D-glucoside (7), and 8 alpha,13 beta-dihydroxy-labd-14-en-2 alpha-O-beta-D-glucoside (10) by chemical, enzymic, and spectral data, especially 2D-n.m.r. techniques and thermospray liquid chromatography-mass spectrometry analysis.