ABSTRACT
Objective: To establish an HPLC method for the simultaneous determination of the main flavonoids in the leaves of Apocynum venetum and Poacynum hendersonii, and to reveal the differences of flavonoids in Apocyni Veneti Herba located between Xinjiang and other areas in China. Methods: The leaves of the two kinds of Apocyni Veneti Herba were extracted with 60% ethanol by reflux extraction. The separation was carried out on an Agilent TC-C18 column (150 mm × 4.6 mm, 5 μm) eluted with the mobile phases of acetonitrile-0.1% phosphoric acid (16:84). The column temperature was 40°C, and the flow rate was 1.0 mL/min, the detection wavelength was 360 nm, and the column temperature was 40°C. Results: The linear ranges of rutin, hyperin, and isoquercitrin were 4.96-49.60 (r = 0.9992), 0.96-9.60 (r = 0.9990) and 10.24-102.40 μg/mL (r = 0.9970), respectively; and the average recoveries (n = 5) were 98.2% (RSD = 1.5%), 92.3% (RSD = 3.2%), and 100.1% (RSD = 2.7%), respectively. Conclusion: This method is simple, rapid, accurate, and reproducible, and the results show that the flavonoids in Apocyni Veneti Herba located in Xinjiang are remarkably different from those in the other areas in China. In the leaves of A. venetum located in Xinjiang, the lutin content is high, about 0.55%, close to the isoquercetin content, but the hypercetin content is very low, only about 0.07%, and in the leaves of P. hendersonii, the contents of both lutin and hypercetin are very small. Such study will offer the credible method for the quality control of A. venetum and P. hendersonii.
ABSTRACT
Objective: To study the nonflavonoid constituents in the leaves of Apocynum venetum, the medicinal halophyte. Methods: The constituents were isolated and purified by silica gel and Sephadex LH-20 column chromatography as well as preparative HPLC, and their structures were elucidated by means of physicochemical properties and spectrosocpic analyses. Results: Fifteen nonflavonoid compounds were isolated from the methanol extract from the leaves of A. venetum, and identified as scopoletin (1), esculetin (2), methyl chlorogenate (3), chlorogenic acid (4), grasshopper ketone (5), benzyl-O-β-D-glucopyranoside (6), 2-phenylethyl-O-β-D-glucopyranoside (7), 1-β-O-benzoyl-D-glucopyranoside (8), tyrosol (9), isovanillic acid (10), vanillic acid (11), protocatechuic acid (12), lupeol (13), β-amyrin (14), and α-linolenic acid (15). Conclusion: Compounds 2, 3, 5-10, 14, and 15 are isolated from this plant and the plants in Apocynum Linn. for the first time.
