Dynamic changes of volatile components in Forsythia suspensa at different harvest periods based on GC-MS and chemometrics analysis / 中国中药杂志

Forsythiae Fructus is the dried fruit of Forsythia suspensa and the volatile compounds are its main bioactive components. According to the different harvest periods, F. suspensa can be divided into Qingqiao(mature F. suspensa) and Laoqiao(ripe F. suspensa). To investigate dynamic changes of volatile components in Qingqiao and Laoqiao samples collected at different periods, the present study extracted and analyzed the total volatile oils in Qingqiao and Laoqiao samples(four harvest periods for Qingqiao and two for Laoqiao) by steam distillation method. The results indicated that the content of volatile oils in F. suspensa samples at different harvest periods was significantly different. The content of volatile oils in Qingqiao samples(except those harvested in the first period) was higher than that of Laoqiao, and the content of volatile oils in both Qingqiao and Laoqiao increased with the harvest period. Furthermore, volatile compounds in F. suspensa were qualitatively analyzed by the gas chromatography-mass spectrometry(GC-MS), and 28 volatile compounds were identified. Chemometrics analyses including principal component analysis(PCA) and partial least squares discriminant analysis(PLS-DA) were further applied to explore differential markers and dynamic changes of volatile components in Qingqiao and Laoqiao samples at different harvest periods. Finally, four volatile compounds, including α-pinene, sabinene, β-pinene, and 4-terpenol were selected as potential differential markers. The relative content of α-pinene and 4-terpenol was consistent with that of total volatile oils in the changing trend.

Dynamic changes of volatile components of Qiai from different harvest time based on GC-MS and chemometrics analysis / 中国中药杂志

Artemisiae Argyi Folium, the dried leaves of Artemisia argyi, has been widely used in traditional Chinese and folk medicines for a long time. Qiai is one of the top-geoherb of Artemisiae Argyi Folium. Qiai contains various bioactive constituents, such as volatile oils, phenolic acids, flavonoids and terpenoids. Phytochemical studies demonstrated that volatile compounds are the main bioactive constituents in Qiai. Try to investigate dynamic changes of volatile components of Qiai from different harvest time and explore the optimum harvest time of Qiai, in this study, the contents of total volatile oils in Qiai collected from five different harvest time were analyzed by steam distillation method. The results showed that the contents of volatile oils of Qiai were higher in the third harvest time(around the Dragon Boat Festival), which is basically consistent with the traditional harvest time. Furthermore, a sensitive method based on gas chromatography-mass spectrometry(GC-MS) was established for qualitative analysis of volatile compounds in Qiai, and a total of thirty volatile compounds were identified. Chemometrics methods including principal component analysis(PCA) and orthogonal partial least-squares discriminate analysis(OPLS-DA) were applied to explore chemical markers and dynamic changes of volatile components in Qiai from different harvest time, and the results indicated that there were obvious differences in the relative contents of volatile compounds of Qiai samples from different harvest time. Eight volatile compounds, including α-terpinene, γ-terpinene, D-camphor, trans-carveol, α-copaene, isobornylisobutyrate, humulene, and caryophyllene oxide were selected as potential chemical markers. Among the eight chemical markers, the relative contents of α-terpinene, γ-terpinene, α-copaene and caryophyllene oxide were higher in the third harvest period(around the Dragon Boat Festival), which is consistent with the contents of total volatile oils. The present study could provide the basis for investigating the optimum harvest time of Qiai, and might be useful for the quality control of this herbal medicine.