Synthesis, estrogenic activity, and anti-osteoporosis effects in ovariectomized rats of resveratrol oligomer derivatives.

Three series of resveratrol oligomer derivatives were synthesized, including the indenone-type, indene-type and octahydropentalene-type derivatives, among which ten derivatives were novel compounds. Compounds 2, 14f, and 4d were confirmed as ERβ agonists by yeast two-hybrid assay, and compound 2 (isopaucifloral F) was further chosen to evaluate its anti-osteoporosis activity in vivo. Compared with the sham-operated and the positive control groups, isopaucifloral F (10 μg/kg) showed a notable anti-osteoporosis effect in the ovariectomized (OVX) female rats based on a micro-CT analysis and the following measurements: bone mineral density, bone volume/tissue volume, trabecular thickness, trabecular separation/spacing, and the serum biochemical parameters. LD50 of isopaucifloral F was found to be greater than 5 mg/kg and its effective dose (ED) was found to be about 10 μg/kg. Therefore, isopaucifloral F may be a promising lead compound for the treatment of postmenopausal osteoporosis.