Hwang Eun-Young, Lee Je-Hyun, Lee Yong-Moon, Hong Seon-Pyo
Department of Oriental Pharmaceutical Sciences, Kyung Hee University, Seoul, Korea.
Chem Pharm Bull (Tokyo). 2002 Oct;50(10):1373-5. doi: 10.1248/cpb.50.1373.
In boiling aqueous solution, D-amygdalin usually begins to convert into neoamygdalin in 3 min and more than 30% of the initial D-amygdalin is found as neoamygdalin after 30 min. In this report, we establish methods for simple HPLC analysis and the inhibition of D-amygdalin conversion. D-Amygdalin and its conversion product, neoamygdalin, were clearly separated on reverse-phase column chromatography by an optimized eluent of 10 mM sodium phosphate buffer (pH 3.8) containing 6% acetonitrile. Linearity for analyzing D-amygdalin and neoamygdalin was observed in the range from 0.05 to 0.5 mM. The detection limits for D-amygdalin and neoamygdalin were ca. 5 microM per injected amount. We found that D-amygdalin conversion was completely inhibited by adding 0.05% citric acid to the aqueous solution before boiling. To prevent the loss of pharmaceutical potency of Tonin, we applied this method to measure the conversion rate of D-amygdalin. We confirmed that D-amygdalin conversion in Tonin is effectively inhibited by acidic boiling solution with 0.1% citric acid.
在沸腾的水溶液中，D-苦杏仁苷通常在3分钟内开始转化为新苦杏仁苷，30分钟后，超过30%的初始D-苦杏仁苷会转化为新苦杏仁苷。在本报告中，我们建立了简单的高效液相色谱（HPLC）分析方法以及抑制D-苦杏仁苷转化的方法。通过优化的流动相（含6%乙腈的10 mM磷酸钠缓冲液，pH 3.8），D-苦杏仁苷及其转化产物新苦杏仁苷在反相柱色谱上得到了清晰分离。分析D-苦杏仁苷和新苦杏仁苷的线性范围为0.05至0.5 mM。D-苦杏仁苷和新苦杏仁苷的检测限约为每次进样量5 microM。我们发现，在沸腾前向水溶液中加入0.05%的柠檬酸可完全抑制D-苦杏仁苷的转化。为防止托宁药效损失，我们应用此方法来测定D-苦杏仁苷的转化率。我们证实，含0.1%柠檬酸的酸性沸腾溶液可有效抑制托宁中D-苦杏仁苷的转化。
