3种常见中药材中绿原酸类成分提取的“逆溶解度”现象

目的 揭示艾叶、菊花和金银花中绿原酸类成分的提取规律。方法 运用超高效液相色谱法（UHPLC）测定艾叶、菊花和金银花中绿原酸类成分在常见溶剂水和乙醇中的溶解度，采用超声辅助法和加热回流法比较3种中药材中绿原酸类成分在水和乙醇中的提取率，并考察各绿原酸类成分在不同体积分数乙醇中的提取规律。结果 7个绿原酸类成分在乙醇中的溶解浓度远大于纯水；菊科植物艾叶和菊花超声提取在乙醇中的提取率显著低于纯水，加热回流提取除异绿原酸A外，其余绿原酸类成分在乙醇中的提取率均显著低于纯水；忍冬科植物金银花超声提取新绿原酸、绿原酸和隐绿原酸在乙醇中的提取率略低于纯水，加热回流提取新绿原酸、隐绿原酸和异绿原酸B在乙醇中的提取率显著低于纯水。上述结果表明，中药绿原酸类成分提取过程中存在“逆溶解度”现象，即中药材中绿原酸类成分在某种溶剂中的提取率与其在该溶剂中的溶解性能相反的现象。在不同体积分数乙醇中，金银花中绿原酸类成分含量都是随乙醇体积分数的升高而先升高后降低，在体积分数为50%时绿原酸类成分含量达到最高点；菊科植物艾叶、菊花中新绿原酸、隐绿原酸等多种成分含量随乙醇体积分数的升高而降低，展现出显著的“逆溶解度”现象，在纯水中含量最高，但不同植物中也略有差异。结论 揭示了中药材中绿原酸类成分提取的“逆溶解度”现象，将为绿原酸类成分的提取及后续深入研究、开发应用提供参考。

Phenomenon of Retrograde Solubility in the Extraction of Chlorogenic Acids from Three Common Chinese Medicinal Materials

Objective To reveal the extraction rules of chlorogenic acids in three common Chinese medicinal materials.Methods In this paper, the solubility of chlorogenic acids in Artemisia argyi, Chrysanthemum morifolium and Lonicera japonica in water and ethanol was separately determined by ultra-high performance liquid chromatography (UHPLC), and their extraction efficiency was compared by ultrasonic-assisted method and heat reflux method. In addition, the extraction rules of chlorogenic acids in various volume fractions of ethanol were investigated.Results The solubility of seven chlorogenic acids in ethanol was much higher than that in pure water. The extraction efficiency of chlorogenic acids in A. argyi and Ch. morifolium in ethanol by ultrasonic-assisted method was significantly lower than that in pure water, and in heat reflux extraction, chlorogenic acids except isochlorogenic acid A had markedly lower extraction efficiency in ethanol than in pure water. In the ultrasonic-assisted extraction of L. japonica, the extraction efficiency of neochlorogenic acid, chlorogenic acid and cryptochlorogenic acid in ethanol was slightly lower than that in pure water, while neochlorogenic acid, cryptochlorogenic acid and isochlorogenic acid B had lower extraction efficiency in ethanol than in pure water during heat reflux extraction. The above results showed that the phenomenon of retrograde solubility occurred in the extraction process of chlorogenic acids in Chinese medicinal materials. That was, the extraction efficiency of chlorogenic acids in Chinese medicinal materials in a certain solvent was opposite to their solubility in this solvent. In different volume fractions of ethanol, the content of chlorogenic acids in L. japonica was firstly increased and then decreased with the increase of the volume fraction, and reached the maximum when the volume fraction was 50%. However, multiple components such as neochlorogenic acid and cryptochlorogenic acid had reduced content in A. argyi and Ch. morifolium with increased volume fraction of ethanol, showing an obvious phenomenon of retrograde solubility, and the highest content was found in pure water, but with slight differences among different plants.Conclusion In this study, the phenomenon of retrograde solubility in the extraction of chlorogenic acids in Chinese medicinal materials was revealed for the first time, which provided reference for the extraction, further study, development and application of chlorogenic acids.