Extraction And Separation Of Effective Components From Hawthorn Leaves And Its Application

Hawthorn leaf was used as a traditional Chinese medicinal materials in medicinal history of nearly one thousand years in our country, which has the functions of preventing cardiovascular disease, antihyperglyceic, anti-aging, antibacterial and so on. China as the origin country of hawthorn has the richest resources of wide cultivated area and various varieties. People tend to put more focus on the utilization of hawthorn fruit, but neglect the application value of hawthorn leaves. There are millions of tons hawthorn leaves being abandoned, which not only wastes huge resources, but also causes certain pollution to the environment. There are amounts of flavonoids and triterpenoids compounds in hawthorn leaf, which are the main pharmacological active ingredients of hawthorn leaf. It is important to investigate active compounds extraction and its activity, and develop new hawthorn leaf function products. The research not only can improve the utilization value of hawthorn leaf, and extend the processing industrial chain of hawthorn leaf, but also realize the hugest utilization value of functional component in hawthorn leaf. Therefore, there are important economic value and social significance to investigate high utilization value of hawthorn leaf and develop new health products. This main content and research results are as follows:1. We applied Ultrasound-assisted ethanol extraction technology to extract flavonoids, On the basis of single-factor test, the response surface methodology was used to investigate the effects processing parameters, including ethanol concentration, solid-liquid ratio, extraction time and temperature. The yield of total flavonoids was chosen as response value, mathematical model was established by implementing four factors and three levels. The best extraction technology conditions could be obtained by the analyzing of response surface. The best extraction technology conditions were ethanol concentration of 70%, solid-liquid ratio of 1:35, extraction time of 39 min and extraction temperature of 72℃. The actual flavonoids yield was 28.991 mg/g, which showed 91.9% higher than ordinary extraction and 39% higher than ethanol refluxing extraction.2. Hawthorn leaves flavonoids showed strong inhibition of α-glucosidase, its IC50 value was 1.36 mg/mL, which was significantly lower than the positive control Acarbose(2.75 mg/mL). Its inhibition was 2 times of Acarbose. Its IC50 value was 1.34 mg/mL to inhibit α- amylase. Although its inhibiting effect was weaker than Acarbose, hawthorn leaves flavonoids showed better inhibition effect than other α-amylase inhibitors from plant sources. Investigation in vitro had shown that the flavonoids of hawthorn leaves has good ability to scavenge DPPH and ABTS free radicals, and IC50 value were 754.66μg/mL, 113.47μg/mL. It also has certain reduction of Fe3+. However its antioxidant activity was significantly weaker than positive control Vc.3. We applied all kinds of separation technology to separate water insoluble parts and ethyl acetate parts of hawthorn leaf by active tracking method. Compound 1 and Compound 2 were isolated from water insoluble parts and ethyl acetate parts, which had strong activity to inhibit α-glucosidase. Compound 3 of good inhibition to α-amylase was separated from ethyl acetate parts. They were Quercetin(1), Uosolic Acid(2) and Quercetin 3-O-β-D-glucoside(3) by NMR, IR identification technology. The IC50 value of Quercetin and Uosolic Acid were 0.113 mg/mL, 0.014 mg/mL, which were far lower than the positive control Acarbose(2.75 mg/mL). It had shown better inhibiting activity to α-glucosidase. They showed noncompetitive type manner on α-glucosidase.The IC50 value of Quercetin 3-O-β-D-glucoside was 0.851 mg/mL, which was weaker than Acarbose. However it still showed good inhibition effect to α-amylase enzyme. It showed competitive type manner on α-amylase.4. We made hawthorn green tea and hawthorn black tea according to certain processing technology. Biochemical index determination showed that hawthorn green tea had high content flavonoid(24.3 mg/g) and polyphenol(15.4 mg/g). Compared with fresh hawthorn leaf, it had little change. The flavonoids and polyphenols content of hawthorn black tea reduced greatly. Determination of amino acids showed that total amino acid content of hawthorn green tea was 121.16 mg/g, which was 33.08% higher than hawthorn leaf. The total amino acid content of hawthorn black tea was 67.495 mg/g, which was 25.86% lower than the hawthorn leaf. Aroma components showed that hawthorn green tea had 43 kinds of volatile components. There were some high content compositions such as ionone, eugenol, hyacinthin, linalool, phytol, nonanal and so on, which were the characteristics aroma substance of green tea. hawthorn black tea had 52 kinds of volatile components, There were some high content compositions such as linalool, ionone, geranyl acetone, 3,5-symplectic diene-2-ketone, α-terpineol and so on, which made hawthorn black tea with Chen fragrant and costustoot.