A process for producing catechins from tannic substance which has been extracted from tea leaves. An aqueous solution of the extract is admixed with an aqueous solution of caffeine to form a liquid-containing mixture of free catechins and a precipitated mixture of ester-type catechins. The caffeine is then removed from the aforesaid mixtures, and the respective mixtures fractionated to obtain epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate.
The present invention relates to the use of O-substituted derivatives of (+)-cyanidan-3-ol corresponding to the formula ##STR1## and their addition salts, in which R represents an optionally substituted hydrocarbon radical, an acyl radical of an organic carboxylic acid containing at least 2 carbon atoms, of a carbonic acid, or of an organic sulphonic acid, of a radical of an inorganic acid containing at least one oxygen atom, as compounds having immunomodulating properties, and pharmaceutical compositions for this purpose.
Catechin complexes are obtained from aqueous extracts obtained from plants containing catechins. The extracts are concentrated to a liquor, and the liquor then is extracted with dichloromethane to eliminate pigments from the liquor and to obtain an aqueous phase, which contains catechin complexes, and a dichloromethane phase. The aqueous phase is mixed with purified sea sand to form a paste which is eluted with acetone to obtain the catechin complexes in the acetone. The catechin complexes are recovered from the acetone by evaporating the acetone, and the recovered catechin complexes may be dried to obtain a powder.
Unsubstituted or substituted 6-amino-1,2-benzopyrones are potent, selective and non-toxic inhibitors and suppressants of viral infections in a mammalian host. The compounds are particularly useful for treatment of AIDS, herpetic episodes and cytomegaloviral infections. The method of treatment of viral diseases by 6-amino-1,2-benzopyrones is described.
Extract of tea leaves or (-)-epigallocatechin gallate as the principal ingredient of the extract forms a complex with active aluminum hydroxide. The animal test using rats has established that these complexes have therapeutic effect for gastric ulcers, e.g. pylorus-ligated ulcer and indomethacin-induced ulcer, when orally administered. Tests were also undertaken for the effect on the secretion of gastric juice and acute toxicity of these complexes using rats and mice as the test animals.
A process for producing a natural antioxidant from tea leaves comprising treating said tea leaves with a solvent selected from the group consisting of hot water (preferably 80.degree. C.-100.degree. C.), a 40-75% aqueous solution of methanol, a 40-75% aqueous solution of ethanol and a 30-80% aqueous solution of acetone to obtain an extract-containing solution; washing the extract-containing solution with chloroform to obtain a washed extract; combining the washed extract with an organic solvent to transfer said washed extract into said organic solvent; removing the organic solvent; and drying the resulting extract. The invention also provides the natural antioxidant produced by the aforesaid process.
