基于热分析技术的甘草制甘遂的炮制机制研究

Preliminary investigation on processing mechanism of Kansui Radix by liquorice based on thermal analysis technology

运用热分析技术,以模拟空气(N2-O2 4∶1)为载气,选取10℃·min-1的升温速率,体积流量为60 mL·min-1,分别对甘遂生品、甘遂醇提物、石油醚萃取物、氯仿萃取物、乙酸乙酯萃取物、正丁醇萃取物及其甘草汁拌制品进行热解特性分析。结果发现,由于萃取溶剂极性的不同,各极性部位所含化学成分的种类及数量发生变化,且随着甘草汁固体粉末加入量的增加,最大热失重速率峰均提前,石油醚、氯仿、乙酸乙酯部位分别提前(157.40±1.06),3.50,(25.83±1.66)℃,但是热失重率除氯仿部位增加(2.62±5.19)℃外,石油醚、乙酸乙酯部位却分别减少(33.90±1.72),(19.28±1.11)℃。可见甘草汁的加入,使得甘遂的毒性部位石油醚部位及氯仿部位的热解速率增加,最大热失重速率峰的温度点降低,同时药效部位乙酸乙酯部位虽然在升温过程中亦有所下降,但是整体失重率及失重速率相对较小,达到保留药效成分的作用,证明了甘草制甘遂炮制后减毒的机制以及甘草制甘遂的科学性及合理性。同时,随着加入甘草汁比例的增大,石油醚、氯仿、乙酸乙酯部位的最大热失重速率峰均提前,峰温降低,易于热解。其中石油醚、氯仿部位10∶1混合物的热失重速率相对较大,峰温较低,而乙酸乙酯则正好相反。此结论对于甘遂与甘草的比例具有一定的指导意义。

In the thermal analysis, the pyrolysis characteristics of crude Kansui Radix, alcohol extract of Kansui Radix, petroleum ether extract, chloroform extract, ethyl acetate extract, n-butanol extract, and licorice vinegar were analyzed with simulated air(N2-O2 4∶1) as the carrier gas, at a temperature increase rate of 10 ℃·min-1 and a volume flow rate of 60 mL·min-1, respectively. The results showed that due to the different polarity of the extraction solvent, the type and quantity of the chemical components contained in each polar part were different, and with the increase in the amount of solid powder of licorice, the peak of the maximum heat loss rate occurred in advance. For petroleum ether, chloroform, and ethyl acetate fractions,(157.40±1.06), 3.50,(25.83±1.66) ℃ in advance respectively, but the weight loss rate of the chloroform fraction was increased by(2.62±5.19) ℃, while decreased by(33.90±1.72),(19.28±1.11) ℃ for the petroleum ether and ethyl acetate fractions. So we can conclude that with the addition of licorice, the pyrolysis rate of the petroleum ether and chloroform fractions in the toxic part of Kansui Radix was increased;the temperature point at the peak of the maximum weight loss rate was decreased, and the ethyl acetate fraction(effective part) showed a decrease in temperature rising process, but its overall ratio of weight loss and weight loss rate were relatively small, retaining the effect of medicinal ingredients. This proved the mechanism of licorice system Kansui Radix on attenuating toxicity after processing and the scientificity and rationality of licorice system Kansui Radix. At the same time, as the proportion of glycyrrhizin was increased, the peak of the maximum heat loss rate of petroleum ether, chloroform and ethyl acetate fractions occurred in advance;the peak temperature was decreased, with easy pyrolysis. Among them, the thermogravimetric rate of the mixture of petroleum ether and chloroform fractions(10∶1) was relatively large, with a low peak temperature, while ethyl acetate fraction showed opposite results. This conclusion has certain guiding significance for the ratio of gansui to licorice.