钩藤中钩藤碱、异钩藤碱的提取与含量测定

目的 研究和探讨钩藤药材中钩藤碱与异钩藤碱的最佳提取与含量测定方法.方法 采用Phenomenex C18柱(4.6 mm×150 mm,5μm),以甲醇-0.01 mmol·L-1三乙胺水溶液(70:30,冰醋酸调pH 7.0)为流动相;流速:0.5 mL·min-1;柱温:30℃;进样器温度:5℃;检测波长为245 nm,测定和考察钩藤不同时间的水煎液和不同条件下甲醇冷浸超声提取液中主要有效成分钩藤碱和异钩藤碱含量的变化.结果 钩藤碱回归方程Y=76.7170X-0.0727(r=0.999 8),在2.5～80.0μg·mL-1范围内线性关系良好,平均加样回收率99.84%～116.91%,RSD小于8.8%;异钩藤碱回归方程Y=87.4729X-0.3666(r=0.999 7),在2.0～80.0μg·mL-1范围内线性关系良好,平均加样回收率87.08～104.97%,RSD小于7.3%;甲醇冷浸超声提取液中钩藤碱与异钩藤碱的提取率大约是水煎液中的十倍.在甲醇提取工艺中,影响提取率的因素从大到小依次为超声时间、甲醇用量、冷浸时间,经正交实验优选的最佳提取工艺为用20倍质量的甲醇,冷浸24h,超声60min.结论 钩藤药材中有效成分钩藤碱与异钩藤碱的提取,采用甲醇冷浸超声法优于水煎法.该含量测定方法快速、简便、准确,可为评价钩藤药材的质量提供依据.

Extraction and Determination of Rhynchophylline and Isorhynchophylline in Ramulus Uneariae cum Uncis

Objective To explore the optimal method of extraction and determination of rhynchophylline and isorhynchophylline in Ramulus Uncariae cum Uncis. Methods A RP-HPLC was performed on a Phenomenex C18 column (4. 6 mm× 150 mm, 5m) at 30℃. The mobile phase consisted of methanol-0. 01 mmol/L triethylamine solution (70: 30, pH 7.0 adjusted by glacial acetic acid) at the flow rate of 0. 5 mL/min. The automatic sample injector was set at 5℃ and the ultraviolet detector was operated at 245 nm. And then, the effect of different extraction condition on the contents of rhynchophylline and isorhyn-ehophylline in Ramulus Uncariae cum Uncis was investigated. Results A good linearity of rhynchophylline was in the range of 2. 5μg/mL to 80. 0μg/mL (Y=76. 7170X-0. 0727, r=0. 999 8), the average recoveries were from 99. 84 ％ to 116. 91％, and the RSD (n=6) were less than 8.8 ％. A good linearity of isorhynchophylline was in the range of 2. 0 μg/mL to 80. 0 μg/mL (Y=87. 4729X-0. 3666, r=0.999 7), the average recoveries were from 87.08 ％ to 104. 97 ％, and the RSD (n=6) were less than 7.3 ％. The contents of rhynchophylline and isorhynchophylline in the methanol-extracted solu- tion were approximately ten times as much as those in water-decocted solution. The main factors which had effect on the ex-traction of rhynchophyUine and isorhynchophylline in methanol solution were supersonic time, methanol amount and cold-dousing time, in a decreasing sequence. The best condition selected by orthogonal experiment wasb as follows: extracting the medicinal material with 20-fold volumes of methanol, cold maceration for 24h and supersonic extraction for 1 h. Conclusion The extraction percentage of rhynchophylline and isorhynchophylline in the extraction condition of cold maceration with methanol and supersonic extraction is superior to that in the water-decocting condition. The method is simple, fast and accurate, and it can be used for the quality control of Ramulus Uncariae cum Uncis.