Chemical analysis, pharmacological activity and process optimization of the proportion of bilobalide and ginkgolides in Ginkgo biloba extract.

•Variations in the ratio of BB and ginkgolides were detected in ginkgo preparations.•Ratio of BB and ginkgolides at 1:2 possesses better antithrombotic effects in vivo.•Extraction process was optimized to approach the better BB and ginkgolides ratio.•Ratio of BB and ginkgolides should be used as a quality control in ginkgo products.