111397-00-3

Upstream product

• 111421-89-7 1,3-bisbenzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol 
• 863-03-6 (-)-epicatechin gallate 
• 490-46-0 (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol 
• 154-23-4 catechin 
• 154-23-4 (-)-catechin 

Relevant academic research and scientific papers

Biotransformation of (-)-epicatechin 3-O-gallate by human intestinal bacteria

The biotransformation of (-)-epicatechin 3-O-gallate (1) and related compounds was undertaken using a human fecal suspension. Of fifteen metabolites isolated, four compounds were new, namely, two epimers of 1-(3'- hydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl)propan-2-ols (6, 19); 2'',3''- dihydroxyphenoxyl 3-(3',4'-dihydroxyphenyl)propionate (14) and 1-(3',4'- dihydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl)propan-2-ol (18). (-)- Epicatechin (2), (-)-epigallocatechin (16) and their 3-O-gallates (1, 17) were extensively metabolized by a human fecal suspension after incubation for 24 h, whereas the gallates (1, 17) resisted any degradation by a rat fecal suspension, even after a prolonged incubation time (48 h), suggesting a difference in metabolic ability between two intestinal bacterial mixtures from different species.

Isolation and characterization of a human intestinal bacterium Eggerthella sp. CAT-1 capable of cleaving the C-Ring of (+)-catechin and (-)-Epicatechin, followed by p-dehydroxylation of the B-ring

We isolated a human intestinal bacterium, capable of cleaving the C-ring and dehydroxylating the Bring of both (+)-catechin (2 R ,3S ) and (-)-epicatechin (2 R ,3R). Although the strain was classified as Eggerthella (Eg.) lenta [named Eg. sp. CAT-1 (JF798636)] by 16S ribosomal RNA (rRNA) gene similarity, it was quite different in substrate specificity from a previously isolated strain, Eg. sp. SDG-2, which takes part in cleavage of the C-ring and dehydroxylation of the 3,4-dihydroxyphenyl moiety (B-ring) of (3R)-flavan-3-ol derivatives. On the other hand, both Eg. sp. CAT-1 and Eg. sp. SDG-2 showed the same substrate specificity against dehydroxylation of enantiomeric lignans, (+)- and (-)-dihydroxyenterodiol, and (+)- and (-)-dihydroxyenterolactone.

The heterocyclic ring fission and dehydroxylation of catechins and related compounds by Eubacterium sp. strain SDG-2, a human intestinal bacterium

A human intestinal bacterium, Eubacterium (E.) sp. strain SDG-2, was tested for its ability to metabolize various (3R)- and (3S)-flavan-3-ols and their 3-O-gallates. This bacterium cleaved the C-ring of (3R)- and (3S)flavan-3-ols to give 1,3-diphenylpropan-2-ol derivatives, but not their 3-O-gallates. Furthermore, E. sp. strain SDG-2 had the ability of p-dehydroxylation in the B-ring of (3R)-flavan-3-ols, such as (-)-catechin, (-)-epicatechin, (-)-gallocatechin and (-)-epigallocatechin, but not of (3S)-flavan-3-ols, such as (+)-catechin and (+)-epicatechin.

Condensed Tannins: Base-Catalysed Reactions of Polymeric Procyanidins with Toluene-α-thiol. Lability of the Interflavanoid Bond and Pyran Ring.

Reaction of polymeric procyanidins (condensed tannins) with toluene-α-thiol at pH 12.0 and 23 degC gave predominantly one stereoisomer of 1,3-bisbenzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (10) by stereoselective reaction at C-4 and C-2 of the quinone methide derived from the upper 2,3-cis procyanidin units.Smaller amounts of two isomers of 1-benzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (4) were obtained by reaction at the C-2 of catechin obtained from the terminal units.At higher temperatures, (10) loses toluen-α-thiol preferentially from C-1 to give 1-benzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)-propan-2-one (11) by a tautomeric rearrangement of the quinone methide via an enol to the keton.Loss of toluene-α-thiol from (4) gave 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-one (5) by a similar rearrangement.This compound further rearranges to 1-(3,4-dihydroxyphenyl)-4,6-dihydroxyindan-2-one (6).