Extraction and Determination of Rhynchophylline and Isorhynchophylline in Ramulus Uneariae cum Uncis / 中药新药与临床药理

ABSTRACT

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. ResultsA 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.