Analysis for ~1H NMR fingerprint of Radix Daphne genkwa / 中成药

ABSTRACT

AIM: To establish ()~1H NMR fingerprint of Radix Daphne genkwa to disclose its chemical composition of the secondary metabolites and provide a quick and credible assay for the detoxicated extraction of the active constituents. METHODS: The ()~1H NMR spectrum of petrol-acetone-methanol extract from Radix Dephne genkwa was detected using CDCl_3/DMSO-d_6(1∶1) as the deuterium reagent. The resonance intensity of the proton in the spectrum was indicated in relative integral area of peaks referenced by the resonance intensity of methyl signal in DMSO. The ()~1H NMR of cascade extraction of Radix Dephne genkwa by the reagent in sequence of petrol→acetone→methanol or chloroform→aether→acetyl acetate→methanol was utilized for observing the variation on their chemical compositions. RESULTS: The ()~1H NMR of Radix Dephne genkwa clearly expressed the information of the protons from long chain aliphatics or genkwadaphnin derivatives, aromatic coumarins or flavonoids as well as glycosides with moiety(ies) of pyran saccharide, symbolizing the existence of aliphatics, genkwadaphnin derivatives, coumarins and flavonoids. Remarkable difference was observed in ()~1H NMR spectrum of the extract by different cascade reagent. As the increase in the polarity of reagent, the intensity of the proton signals in upper field was quickly reduced concomitantly with the rapid enhancement of active proton signals from hydroxyls and saccharides in glycosides in down field. CONCLUSION: The ()~1H NMR fingerprint of Radix Dephne genkwa possesses its own characteristics and can be used as a reliable assay for studying the extraction of active constituents with minimum content of toxic diterpenoids. (Key