New rearranged clerodane diterpenes from Tinospora baenzigeri.

Baenzigeroside B, a new rearranged clerodane diterpene glucoside, was isolated from the stems of Tinospora baenzigeri. The aglycone of baenzigeroside B, baenzigeride B (isolated as its acetate), was found together with baenzigeride A, baenzigerosides A and B in the leaves of the same plant. Baenzigeride B and baenzigeroside B are the first examples of a new class of rearranged clerodane diterpenes. The possible biogenesis of the compounds is discussed.