Ginkgolides with anti-PAF activity from Ginkgo biloba L.

Four undescribed ginkgolides, including two rare sesquiterpene ginkgolides (compounds 1 and 2) and two diterpenoid ginkgolides (compounds 3 and 4), were isolated from Ginkgo biloba L. The structures of these four ginkgolides were identified based on extensive spectroscopic analysis, DP4+ probability analysis and X-ray diffraction. Compounds 1 and 2 exhibited excellent antiplatelet aggregation activities with IC50 values of 1.20 ± 0.25 and 4.11 ± 0.34 μM, respectively.