[Explore scientific connotation of "taking when fragranceis volatilized fiercely" for Yinqiao powder based on dynamic changes in contents of volatile components in decoction].

Abstract

To establish a method for the determination of three volatile components: menthone, menthol and pulegone in Yinqiao powder (YQP) decoction, explore the change rules of volatile components in decocting process, and provide evidence for elucidating the scientific connotation of its traditional decocting method "taking when the fragrance is volatilized fiercely". YQP decoctions with different decocting time were prepared, and GC-MS was used to qualitatively analyze the volatile components and determine the contents of menthone, menthol and pulegone in decoctions. Then the effects of different decocting time on contents of volatile components were investigated. The results showed that the volatile components in YQP decoctions mainly come from Menthae Haplocalycis Herba, Schizonepetae Herba and Forsythiae Fructus. With the extension of decocting time, the concentrations of all the above 3 volatile components in Yinqiao powder decoction were first increased and then decreased. When soaking for 30 minutes, as well as boiling for 0, 5, 10, 15, 20, 30, 40, 50, 60 minutes, the concentrations of menthone in YQP decoction were 0.058, 0.268, 0.216, 0.073, 0.065, 0.048, 0.048, 0.041, 0.038, 0.034 mg•L ⁻¹; the concentrations of menthol were 0.965, 2.847, 3.633, 2.420, 1.539, 1.189, 1.273, 1.188, 0.905, 0.663 mg•L ⁻¹; the concentrations of pulegone were 0.355, 0.522, 0.598, 0.477, 0.374, 0.374, 0.339, 0.355, 0.248, 0.251 mg•L ⁻¹; and the total concentrations were 1.377, 3.637, 4.446, 2.970, 1.979, 1.611, 1.660, 1.583, 1.191, 0.947 mg•L ⁻¹, respectively. The results showed that the contents of menthone, menthol and pulegone in YQP decoctions were heavily influenced by the decocting time. The fragrance was volatilized fiercely at about 5 minutes after boiling, with larger concentrations of the above three volatile components in decoction; the fragrance got weak after 15 minutes of boiling, the concentrations of menthone, menthol and pulegone in YQP decoctions were significantly decreased, indicating that the traditional decocting method "taking when the fragrance is volatilized fiercely" has some scientific foundation.