| To examine the volatile compositions from Oxytropis falcata Bunge, the volatiles were obtained using water distillation, supercritical CO2 extraction and headspace extraction methods and their chemical compositions were analyzed by GC and GC/MS.58 compounds were identified and the amount of the identified componunds represented for 71.0%,85.6% and 84.5% of all the volatiles, respectively. The main components were paraffin hydrocarbons 30.1%(water distillation), flavonoids 68.5%(supercritical CO2 extraction) and aldehydes 53.8% (headspace extraction). In addition, micromolecular terpenoids, organic acids, esters and nitrogenous compounds were also identified. It suggested that the retention times of the volatiles extracted using three methods were consecutive which could provide comprehensive volatile compositions of O. falcata Bunge and a scientific basis for further development and utilization of this medicinal plant.To study on the extraction and purification of total alkaloids from Oxytropis falcata Bunge, Firstly, the existence of alkaloids in the material was determined by the preliminary experiments. Then the single-factor and L9 (34) orthogonal test were designed to study the effect of the extraction and purification of total alkaloids from Oxytropis falcata Bunge. The results indicated that the optimum condition on the extraction and purification of total alkaloids from Oxytropis falcata Bunge was as follows:0.5% HAc-40% ethanol solution as extraction solvent, the ratio of raw material powder to solvent was 1.0 g. 20 mL, extraction temperature was 60℃, after ultrasonic extraction (30 min/time×2 times), the cation exchange resins were used to extract and purify total alkaloids from the extracted materials with 1.0% NH3·H2O-60% ethanol solution (30 min/times×3 times). The best yield of total alkaloids could be obtained under this condition.To investigate the contents of total flavonoids and phenolic acids from Oxytropis falcata. We determined the content of total flavonoids by NaNO2-Al(NO3)3-NaOH colorimetric assay with rutin as reference substance. And the content of total phenolic acids by using the Folin-Ciocalteu assay with gallic acid as reference substance. Rutin was found to show a good linear relationship in a range of 4.2-50.4μg/mL. The average recovery was 98.07% and the relative standard deviation (RSD) was 1.488%(n=9). Gallic acid showed a good linearity within a range of 0.804-6.432μg/mL. The average recovery was 98.87% and RSD was 2.484%(n=6). The contents of total flavonoids and phenolic acids in Oxytropis falcata from Tibet An duo, Tibet Bange and Qinghai Gong he were 1.218%,1.296%, 1.139% and 0.530%,0.657%,0.493%, respectively. These two proposed methods are sensitive, precise, accurate and reproducible, and are suitable for the determination of total flavonoids and phenolic acids from Oxytropis falcata Bunge.In addition, various fractions extracted from Oxytropis falcata Bunge were investigated for their antioxidant activities in vitro for the first time. Flavonoid fraction (FF) was major active constituents responsible for the activities on three antioxidant models by total antioxidant activity (148.19±4.12 mg Vc/g), DPPH and hydroxyl radical-scavenging activities, with the IC50 of 53.24±1.42 and 365.66±5.98μg/mL, respectively. The anti-inflammatory mechanism of FF may be due, at least in part, to the decrease of MDA levels (P<0.05) and enhancement of SOD (P <0.35), CAT (P<0.35) and GSH-Px (P<0.01) activities without inducing any gastric damage. The results provide evidences to support the folk medicinal utilization of O. falcata for the treatment of inflammation.Moreover, Oxytropis falcata Bunge has long been regarded as an anti-inflammatory medicinal plant. By the analysis of HPLC-DAD, four flavonoid compounds,2',4'-dihydroxy chalcone (1),7-hydroxy flavonone (2), 5,7-dihydroxy-4'-methoxy flavonol (3) and 5,7-dihydroxy-4'-methoxy flavone-3-O-β-D-galactoside (4), were isolated, identified and quantified.4 was isolated for the first time from this plant. In this study, we focused on evaluating the antioxidant activities of four flavonoid compounds on the total antioxidant activities, DPPH and superoxide radical-scavenging activities, for their cytotoxic and anti-inflammatory activities on the inhibition on LPS-induced NO production in RAW 264.7 cells. Taken together,3 as well as 1 and 2 could contribute, at least in part, to the anti-inflammatory properties of Oxytropis falcata Bunge, which could be used as marker compounds in the standardization and quality control for this medicinal plant. |
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