Study On Chemical Constituents From The Rhizome Of Helleborus Thibetanus Franch

Helleborus Thibetanus Franch., belonging to the family of Ranunculaceae, is a kind of chinese traditional medicines used in some regions of QinLing mountain, and its phytochemistry has not been studied. In this paper, the progress on chemical compositions and pharmacological research were reviewed.The systematic pretests have been carried out by the tube-test methods. The results showed that the Helleborus Thibetanus Franch. Contained carbohydrates, flavonoids, steroid saponins, organic acids, volatile oils etc., no alkaloids, thraquinone and its glycosides.Seven macroporous adsorption resins were selected to examine adsorption properties for total saponins from Helleborus Thibetanus, and the LSA-30 resin possessed the better adsorption ability. The optimized conditions for adsorption and desorption were as following: the concentration of sample was 60 mg/mL; the current velocity of adsorption was 2.0BV/h ; the eluting reagent was 30%-95% EtOH ; eluting rate was 1.0 BV/h ; [NaCl] was 0.5 mol/mL. The content of total saponins was up to 60% in the fraction of 95% ethanolic elution.The optimum procedure of ultrasound-assisted extracting steroid saponins from H.Thibetanus was studied, and a quantitative method to determine total saponins was established. The results indicated that the dominative order of four factors affecting extraction was: concentration of ethanol > extraction time> extraction temperature> dosage of solvent. The optimum conditions of ultrasound-assisted extractinon was as follows: 60℃, 5 times volume of 50% ethanol, the extraction time was 30 min. The yield of total saponins was up to 3.163 %.Thirteen compounds were isolated and purified from the ethanol extracts of the rhizome of Helleborus Thibetanus in conjuction with the use of macroporous adsorption resins, silica gel column chromatography, Sephedex LH-20, re-crystallization. Based on the analysis of their spectral data (MS, UV, IR, 1HNMR, 13CNMR) and the comparation with the related literature data, the thirteen compounds were identified as 9,12-octadecadienoic acid (H-1),β-sitosterol (H-2), stearic acid (H-3), 4-ethoxy-2-hydroxy-4-oxobutanoic acid (H-4), 2-butyl-3-methylsuccinic acid (H-5), hellebrigenin (H-6), 4-hydroxy-3-methoxybenzoic acid (H-7), 4-(2-hydroxyethyl)phenol (H-8), quercetin (H-9), succinic acid (H-10), glucose (H-11), 5-(hydroxymethyl) furfura (H-12), 3,5,14-trihydroxy-19-oxo-3-[(α-L - rhamnopyranosyl)oxy] bufa-20,22-dienolide (H-13).