The pharmacological activity of epicatechin and of certain novel esters and ketals of catechin and of epicatechin is described. The use of said compounds in order to ellicit a choleretic, hypocholesterolimic, hypolipaemic or hepatoprotective effect is described along with pharmaceutical compositions for use in these treatments.
The subject of the present invention is new O-substituted derivatives of (+)-cyanidan-3-ol corresponding to the general formula I ##STR1## 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; or a radical of an inorganic acid containing at least one oxygen atom, with the exception of a glucosidic radical, and the salts thereof, a process for the preparation thereof as well as their application in therapeutics and medicaments containing these new products. These compounds have a valuable activity in the prevention of hepatic necrosis and also inhibit lipoperoxidation. In addition, they are capable of acting on the fibrillation of collagen.
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.
Pharmaceutical preparations containing (+)-cyanidan-3-ol derivatives of the formula I ##STR1## wherein R' and R" are hydrogen, an unsubstituted or substituted hydrocarbon radical, or heterocyclic radical, halogen, formyl, free or functionally modified carboxyl, free or etherified or esterified hydroxyl, free, etherified or oxidized mercapto, unsubstituted or substituted sulfamoyl, acyl or unsubstituted or substituted amino, where however R' and R" cannot both be hydrogen simultaneously, and R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each hydrogen or an unsubstituted or substituted hydrocarbon radical, and R.sub.2 and R.sub.3 together can also be an unsubstituted or substituted methylene group, and R.sub.1 also an acyl group or an amidated carboxyl group; and therapeutically applicable salts of these compounds, as well as new compounds of these preparations. These pharmaceutical preparations are particularly valuable for treating liver and venous diseases.
Compound of the formula ##STR1## in which R and R' represent hydrogen or an optionally substituted hydrocarbon radical or acyl radical, R.sub.1 represents hydrogen or an optionally substituted hydrocarbon radical of aliphatic or aromatic character, R.sub.2 represents hydrogen or an optionally substituted hydrocarbon radical of higher aliphatic or aromatic character, it being possible for R.sub.1 and R.sub.2 together to represent also an optionally substituted alkylene radical or an optionally substituted biphenyl-2,2'-ylene radical, whereby however, when R, R.sub.1 and R.sub.2 are hydrogen, R' cannot be methyl and salts of such compounds that contain a salt-forming grouping, and pharmaceutical compositions containing these compounds. The pharmaceutical compositions containing these compounds are particularly valuable for treating liver and veneous diseases.
A salt of (+)-catechin formed of the reaction product of (+)-catechin with at least a basic amino-acid, such as L-lysine and L-arginine; a hydrosoluble double salt is formed by the reaction product of (+)-catechin with a basic amino-acid, such as L-lysine and L-arginine, and another inorganic or organic acid.
