Tea Catechins
DESCRIPTION:
Tea Catechins, traditionally called
tea tannin, contents
65%-80% in Tea Polyphenol, is the special component of tea leaf
with bitter and acerbic taste as well as astringency.
It has the effects of resisting oxidation, resisting
mutation, preventing tumor, resisting AIDS virus,
lowering blood cholesterol, decreasing lipoprotein
of low density, inhibiting hyperpressure, inhibiting
the congealing of blood platelet, controlling
bacteria, and preventing allergy etc.
They are stronger active
materials formed with catechin as the main structure
combined with gallic acid group. Those of them
exist in green tea are mainly (-)-epigallocatechin
gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin
gallate (ECG), (+)-epicatechin (EC), (-)-gallocatechin
gallate (GCG), and (-)-catechin. The catechin
mainly exists in black tea is theaflavin, which
is a doubly condensed catechin substance based
on (-)-epigallocatechin-3-gallate (EGCG). The
theaflvin has 4 isomers, which are theaflavin-3-gallate,
theaflavin-3'-gallate, theaflavin-3, 3'-digallate
and theaflavin. The catechin substances exist
in Oolong tea are mainly catechin itself and catechin
oligomer.
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