Furanoid diterpene glucosides from Tinospora rumphii

The stems of Tinospora rumphii yielded clerodane type furanoid diterpene glucosides: the new rumphioside I, the known borapetosides C and F and three other compounds. Their structures were established on the basis of various spectroscopic techniques. The three compounds have physical and spectral data identical to those of the reported compounds borapetosides E, D and B, respectively. However, the positions of the lactone rings of the first two compounds and the configuration of the bond attaching the glucose moiety to C-6 of the third differ from the reported ones.