Extraction And Purification Of Chlorogenic Acid From Stems And Leaves Of Lonicera Japonica Thunb.

Chlorogenic acid is a kind of polyphenol compound, which shows wide bioactivity, such as the efficacy of antioxidation, anticancer, antitumor, anti-aging and other healthy functions. It has been widely applied in the fields of medicine, food, daily appliance and its further exploration is of bright prospects. In China, chlorogenic acid is mainly extracted from honeysuckle (Lonicera japonica Thunb.) and skin of Eucommia ulmoides Oliv. The production costing is high and can not meet the requirement of the market. On the other hand, stems and leaves of Lonicera japonica Thunb., which also include rich chlorogenic acid, has been little utilized. Hence, it is of economic significance to develop technology to extract, separate and purify chlorogenic acid from stems and leaves of Lonicera japonica Thunb.In this paper, the extraction and purification technology for chlorogenic acid from stems and leaves of Lonicera japonica Thunb. was studied, aiming at developing a process of low production costing, high extration ratio and purity, low pollution from waste materials, and providing reference for industrial production. The main contents of the study included alcohol refluxing extraction of chlorogenic acid from stems and leaves of Lonicera japonica Thunb., enrichment and purification process by D-101 resin, and refinement of chlorogenic acid by Silica Gel Column and recrystallization. The main results were as follows:1 The extracion ratio of chlorogenic acid by alcohol refluxing extraction and ultrasonic methods was compared, and the former one was chosen as the proper method for extraction of chlorogenic acid from stems and leaves of Lonicera japonica Thunb.. Through single factor, orthogonal and verification experiments, parameters for optimum process were established as follows: ethanol concentration 70%, ratio of material to liquid 1:14, extraction time 2 h, extraction temperature 60℃, solvent pH 6. The average yield for chlorogenic acid was 1.37%.2 Macroporous resin was used for enrichment and purification of chlorgenic acid from stems and leaves of Lonicera japonica Thunb.. Four different kinds of macroporous resins were evaluated with static adsorption and desorption tests. D-101 resin was confirmed as the most suitable resin based on comparison of adsorption capacities, adsorption and desorption ratios. Kinetic curves of adsorption showed that D-101 could absorb chlorogenic acid from crude extract of stems and leaves of Lonicera japonica Thunb. within 2 h, and adsorption isotherms showed that the proper concentration of chlorogenic acid for the sample was 1.01 mg·mL^-1. Optimum parameters were established according to dynamic adsorption and desorption: sample pH 4, flow rate 2 BV·h^-1, sample volume 5 BV, eluent 20% ethanol for 10 BV. Results showed that the final purity and recovery rate reached 50.72% and 54.44%, respectively.3 Extract obtained after the treatment of D-101 resin was further purified through silica gel column chromatography and recrystallization with acetylacetic ester-methanol. The final purity of chlorogenic acid reached 97.96%.In this paper, the extraction, separation and purification process of chlorogenic acid from stems and leaves of Lonicera japonica Thunb was studied systematically, and the process parameters were established for alcohol refluxing extraction, as well as enrichment and purification of chlorogenic acid with D-101 resin. The study also provided important theoretical and experimental reference for large scaled manufacture of chlorogenic acid as well as proper utilization of waste resource of Lonicera japonica Thunb.