Overview | The catechins in tea are mainly phenotypic catechins, namely epigallocatechin gallate EG, epigallocatechin E, epicatechin gallate ECG, epicatechin EC, they account for about 60-80% of the total amount of catechins. Among them, EG is the highest content in green tea polyphenols, and is also the most important antioxidant component in tea. However, the existing research has confirmed that the isomers of the phenotype catechins, such as the epigallocatechin, show strong physiological activity in some aspects, such as antioxidant and scavenging free radical activity. Catechin monomer compounds are mainly extracted from tea or tea extract. The commonly used separation and purification methods include liquid-liquid extraction, column chromatography, medium and low pressure column chromatography, high-pressure preparative liquid chromatography and high-speed countercurrent chromatography separation. There are many other methods for the separation and purification of catechins, and two or more methods are often used in combination. In the literature and patents, it is often seen that the separation and purification reports of Gallic acid catechin gallate EG, epicatechin gallate ECG, etc., but there are few methods for preparing gallic acid catechin monomer compounds. |
Application | catechin has a wide range of biological activities, such as anti-cell proliferation (anti-cancer), antioxidant, anti-inflammatory, anti-cardiovascular disease activity; Also has anti-ultraviolet radiation, weight loss, prevention of diabetes, relieve Parkinson's disease and other effects. For example, the effect of dietary catechin on the absorption of glucose by adipocytes under the condition of high concentration of glucose, the differentiation model of 3T3-L1 preadipocytes was applied, the effect of catechin on glucose uptake and on 3T3-L1 preadipocyte differentiation in adipocytes was determined. The results showed that catechin could promote the glucose absorption stimulated by insulin under the condition of high glucose concentration (30mmol/L) in adipocytes, and accelerate the differentiation of 3T3-L1 preadipocytes. Catechin can increase glucose uptake by adipocytes and promote the differentiation of 3T3-L1 preadipocytes, suggesting that catechin can effectively change blood glucose concentration and improve insulin resistance. |