Ginkgobilol, a new diarylpentanoid and an osteogenic diarylpentanoid analog from Ginkgo biloba leaves

Phytochemical analysis of methanol extracts of Ginkgo biloba leaves resulted in the isolation of a novel diarylpentanoid, ginkgobilol (1) and a known diarylpentanoid analog (2). The structure of the new compound was elucidated by analyzing NMR spectroscopic data and HR-ESIMS, and the absolute configuration was determined using gauge-including atomic orbital NMR chemical shift calculations, followed by DP4+ analysis and specific rotation value. Diarylpentanoids comprise two aromatic rings linked by a five-carbon bridge; these are relatively unique examples in natural products. To the best of our knowledge, the present study is the first to report the presence of diarylpentanoids in G. biloba. Compound 2 increased alkaline phosphatase (ALP) production in C3H10T1/2, a murine mesenchymal stem cell line, in a dose-dependent manner. The promotion of osteogenic differentiation by the active compound 2 mediated by induction of transcriptional ALP and osteopontin (OPN) gene expression was confirmed using quantitative real time polymerase chain reaction, thus indicating its remarkable bone formation activity.