One new clerodane-type furanoditerpenoidtinosinoid A ( 1 ) and nine new nor-clerodane analogs tinosinoids B–J ( 2 − 10 ) have been isolated from the stems ofTinospora sinensis . The structures of the new compoundswith absolute confi gurations have been elucidated by spectroscopicmeans, including MS, NMR and ECD techniques,as well as chemical correlation. Compound 1 is a rare sulfurcontainingclerodane diterpenoid incorporating a 2-mercaptoethanolunit via a thioether bond, while compounds 4 / 5and 9 represent two pairs of unusual equilibrium regioisomersthrough an interesting intramolecular transesterifi cation. Our bioassays established that 1 and 8 displayed moderateantiproliferative eff ects against two human tumor celllines, and 9 and 10 showed signifi cant α -glucosidase inhibitoryactivities. A kinetics study revealed that compound 10was a noncompetitive α -glucosidase inhibitor, and its possiblebinding mode to the enzyme was further probed bymolecular docking experiments.