Diterpenoids From The Roots Of Clerodendrum Bungei

Two new rearranged abietane diterpenoids (1 and 2), together with eleven previously described analogues (3-13), were obtained from the ethanolic extract of a traditional ethnological herb, Clerodendrum bungei. The structures with absolute configurations of the new compounds were unambiguously characterized via spectroscopic methods, and that of the formerly reported crolerodendrum B (3) was corrected in the present work. Biological assessment of these isolates revealed that diterpenoids 2, 4, 6 and 12 showed significant inhibition against alpha-glucosidase enzyme with IC50 values in the range of 17.0-25.7 mu M.