Evaluation of Daphne genkwa diterpenes: Fingerprint and quantitative analysis by high performance liquid chromatography

Daphne genkwa contains a novel class of anticancer diterpene esters that inhibit DNA topoisomerase I. Fingerprint and quantitative analysis by HPLC were performed in order to characterise and evaluate D. genkwa. A standard fingerprint of Daphne diterpene esters from the root extract was first established by HPLC-UV, and the major peaks in the fingerprint profile were preliminarily determined using HPLC-MS. The principal Daphne diterpene esters, yuanhuacine (1), yuanhuadine (2), yuanhuajine (3) and yuanhuagine (4), were isolated and identified using a combination of UV, IR, MS, ¹H-NMR and ¹³C-NMR spectral data. Quantitative analysis indicated that 1 was the principal component in the root, and that 2 was the major component in the buds. The average extraction rates of 1 and 2 were 0.0151 and 0.0033% (n = 10) from the root, respectively, and 0.0020 and 0.0078% (n = 3) from the buds, respectively.