Catechins are an important class of phenolic active substances:
1. Basic information
English name: Catechin, Cianidanol.
Alias: Catechin, Catechic acid, Tea tannin.
Chemical formula: C15H14O6.
Relative molecular mass: 290.28.
Physical state: white needle crystal (water-acetic acid).
Melting point: 212~216℃ (there are different sayings, such as 93~96℃, 175~177℃, etc., may be related to whether the crystals contain water).
Water solubility: soluble in hot water, ethanol, glacial acetic acid, acetone, slightly soluble in cold water and ether, almost insoluble in benzene, chloroform and petroleum ether.
Density: 1.593g/cm³.
Appearance: crystal.
Flash point: 335.04°C.
2. Source and distribution
Catechin was initially extracted from a plant that is not related to tea – the catechu tree. However, catechins are widely distributed in the plant world, is an important component of tea, accounting for 12% 24% of the dry mass of tea, accounting for 60% 80% of tea polyphenols. In addition, catechins or their isomers can also be found in cocoa beans and some other plants.
3. The chemical structure and isomers
Catechin has two benzene rings (A and B ring) and dihydropyran heterocycle (C ring), the carbon 3 on the hydroxyl group. the A ring is similar to the resorcinol part, the B ring is similar to the catechol part.
There are two chiral carbon atoms in the catechin molecule (on carbon atoms 2 and 3) and therefore four stereoisomers exist: (+)-catechin, (-)-catechin, (+)-epicatechin, and (-)-epicatechin. The most common catechin isomer is (+)-catechin.
4. Efficacy and function
Antioxidant: Catechin has the effect of scavenging free radicals, and its antioxidant activity even exceeds that of vitamin E. It can protect cell membranes from oxidative damage by inhibiting lipid peroxidation.
Improve cardiovascular health: Catechin helps to lower cholesterol levels, especially LDL cholesterol, which helps to reduce the risk of atherosclerosis. It also improves vascular endothelial function and promotes blood circulation.
Supports the immune system: By modulating the immune response, catechins may enhance the body’s ability to fight off infections. Some studies point out that catechins may have some inhibitory effect on viral infections.
Supports weight loss: Catechins support the weight loss process by increasing the metabolic rate and aiding in fat oxidation. Clinical trials have shown that catechins can enter the entire body through blood circulation, enhancing metabolism, fat oxidation and energy expenditure, and achieving the effect of suppressing obesity.
Neuroprotective effects: Studies have shown that catechins may have a protective effect on neurons and may play a role in the prevention of neurodegenerative diseases.
Other effects: Catechins also have anti-inflammatory, anti-aging and blood pressure lowering effects. In addition, it precipitates heavy metals and proteins, and has some tanning or tannin properties (but weak tanning properties compared to some typical vegetable tannins such as pentaphyllum tannins).