| Recently, the modernization of Chinese medicines has attracted the attention of workers in pharmacy and even other disciplines and become a focus of research. To achieve the modernization of traditional Chinese medicines, in addition to the cultivation and quality control, the most critical is the extraction and separation process. Recently, many new extraction and separation technologies (such as ultrasound-assisted extraction, microwave-assisted extraction, etc.) has obvious advantages and can significantly improve the yield and purity of the active ingredients. Therefore, the use of new extraction technology is an important way to achieve the modernization of traditional Chinese medicines and is bound to inject new vitality into the modernization of traditional Chinese medicine research.Aimed at the hot and difficult issues of the extraction and analysis of herbal active ingredients for the modernization of traditional Chinese medicines and based on infrared assisted extraction-chromatography technology, this research established a variety of extraction and analysis methods. Through a series of method validation and technical comparison, this research provided innovative ideas and reliable application research for the development of highly selective, efficient, fast and environmentally friendly technologies for the extraction and analysis of herbal active ingredients. The main research content and research results were summarized as follows:The first chapter given an overview of the significance of the herbal active ingredients extraction and analysis technology for the modernization and quality standards of traditional Chinese medicines, introduced several traditional pre-treatment methods in the analysis of herbal active ingredients, overviewed the basic principles, characteristics and their applications of several modern extraction and separation technologies, such as ultrasound assisted extraction, microwave assisted extraction, solid phase micro-extraction, infrared-assisted extraction, etc. in the analysis of herbal active ingredients, and finally presented the purpose and significance of this dissertation.The second chapter adopted response surface methodology instead of traditional orthogonal experiment’s isolated experimental analysis, to study a variety of factors and their interactions on the rutin yield to find the optimal process parameters to obtain the maximum yield of rutin from crude Flos Sophorae Immaturus with the infrared assisted extraction. Through single factor experiment, ranges of the main variables (including methanol concentration, liquid/solid ratio, extraction time and infrared power) affecting the extraction yield of rutin were confirmed. Box-Behnken design consisting of 24 experimental runs and 5 replicates at zero point was then applied and a regress model was obtained to predict the optimal extraction yield. The ANOVA analysis indicated that the regression equation fits very well with the actual situation. The optimal conditions were as follows:infrared power 204.90 W, liquid/solid ratio 30.00 mL/g, methanol concentration 70.00% and extraction time 4.80 min. Under the optimal conditions, the maximum yield (125.70 mg rutin/0.5 g raw material) was consistent with the experimental value (126.32± 0.67 mg rutin/0.5 g raw material) (n=3), indicating the reliability and feasibility of response surface methodology in the optimization of infrared-assisted extraction of rutin from crude Flos Sophorae Immaturus. Subsequently, the application of response surface methodology to the infrared-assisted extraction of a variety of ingredients in Cortex Magnoliae Officinalis, used as the modle sample, was investigated. The results showed that the response surface methodology could be applied not only to the optimization of infrared-assisted extraction of one component, but also could be applied to a variety of ingredients in traditional Chinese medicines. (The research results in this chapter have been published in Phytochemical Analysis (2012,23:292-298), IF:2.633, first author).The third chapter adopted greener non-ionic surfactants instead of commonly used toxic organic solvent to extract picroside I and picroside II from Picrorhiza scrophulariiflora Pennell with the assistance of infrared and determined the conditions for maximum yield. Under optimum conditions, i.e.10% Genapol X-080 (v/v), liquid/solid ratio of 150:1 (mL/g), infrared power 200 W, infrared-assisted extraction for 4 min, the extraction yield reached the highest value. When compared with various polar and nonpolar solvents (pure water, ethanol, acetone, acetic ether and hexane), the extraction efficiency of 10% Genapol X-080 reached statistically higher value (p<0.05). By using infrared-assisted nonionic surfactant extraction method, the determined amounts of the picrosides in Picrorhiza scrophulariiflora Pennell were statistically higher than those extracted with conventional ultrasound-assisted extraction and heat-reflux extraction (p<0.05). Afterwards, the preconcentration of picroside I and picroside II by cloud-point extraction (CPE) was studied and the final concentration factor of 5 was obtained, which may be valuable in the large-scale extraction and purification of picrosides and other herbal active ingredients. The results showed that infrared-assisted nonionic surfactant extraction was a good, efficient and green analytical preparatory technique for the rapid extraction and pre-concentration of pharmacologically active ingredients from Picrorhiza scrophulariiflora Pennell. (The research results in this chapter have been published in Analytical Methods (2013,5: 3747-3753), IF:1.855, first author).The fourth chapter developed a simple, rapid and solvent-free extraction method of infrared distillation-headspace solid phase microextraction/gas chromatography-mass spectrometry (IRD-HS-SPME/GC-qMSD) for the comparative analysis of volatile constituents in two famous Traditional Chinese Medicines from Sophora japonica L., crude Flos Sophorae Immaturus (CFSI) and crude Fructus Sophorae (CFS). CFSI and CFS have been widely used for a long time because of pharmacologic activity, rich resources, low toxicity and costs. The main bioactive constituents of CFSI and CFS include essential oil and flavonoids, etc. Many reports on CFSI and CFS focus on flavonoids, but few on essential oils which could be used in food (as flavorings), perfumes and pharmaceuticals (for their functional properties). After optimization of the extraction methodology, CFSI and CFS were analysed with the best conditions. Compared with conventional HS-SPME, IRD-HS-SPME had shorter extraction time and higher extraction efficiency, indicating that the proposed method was an alternative tool for fast analysis of essential oils in TCMs. A total of 73 and 55 volatile compounds of CFSI and CFS were identified respectively with 25 common compounds in each of them. The results obtained may be helpful for finding out the possibly bioactive compounds of CFSI and CFS and for further exploitation of TCM from Sophora japonica L. and clinical medication. (Journal of Agricultural and Food Chemistry, under review).The fifth chapter developed a temperature-controllable infrared radiation system to accelerate the enzyme pretreatment of traditional Chinese medicines, which would otherwise take several hours to complete, in a relatively constant temperature with the assistance of the infrared radiation. The feasibility and performance of this unique system were demonstrated by enzyme pretreatment of Cnidium monnieri, used as the model sample. To investigate enzymatic pretreatment assisted by infrared energy, experiments were carried out to evaluate the effects that enzyme type, pH and the concentration of the enzyme solution, incubation time and temperature had upon the enzymatic activity. Statistical treatment of the results revealed that the selected parameters were all significant. The optimum parameters were obtained as follows:0.2 mg/mL pectinase solution, and incubated at pH 6.0 for 2 min at 35 ℃. After enzymatic pretreatment under optimal conditions, the extraction yields of osthole and imperatorin by ultrasound assisted extraction were 18.11 mg/g and 7.27 mg/g respectively and increased by 10.2% and 7.9% respectively compared with the control group of direct ultrasound assisted extraction without enzymatic pretreatment. Using infrared radiation as an energy source, the efficiency of enzymatic pretreatment was significantly increased compared with traditional water bath assisted enzymatic pretreatment (p<0.05), and the extraction yields of osthole and imperatorin of infrared assisted extraction were statistically higher than those of ultrasound-assisted extraction (p<0.05). And more importantly, the time of infrared accelerated enzymatic pretreatment was significantly reduced to 2 min compared with 1 h of the conventional water bath assisted enzymatic pretreatment. These results indicated that the use of infrared radiation in accelerating the enzymatic pretreatment to enhance the extraction yields of herbal active ingredients was a very attractive method and should be fully used in the extraction of natural products. With the advantages of environmentally friendly, low-cost, easy operation, high efficiency, etc., infrared accelerated enzymatic pretreatment was expected to be widely used in industrial fields. (The research results in this chapter have been published in Analytical Methods (2013,5:5669-5676), IF:1.855, first author). |
