Isolation of 1-(3′,4′-Dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)-propan-2-ol from Grape Seed Extract and Evaluation of its Antioxidant and Antispasmodic Potential

Abstract

HPLC profiling of phenolics in grape seed extracts revealed a prominent peak of an unknown substance with concentrations up to 5.3%. Spectroscopic data allowed the identification of the compound 1 as 1-(3′,4′-dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)-propan-2-ol. 1 is known to be produced from catechin and epicatechin through anaerobic bacteria from human, as well as the rat, intestines. It was hypothesized that the marc remaining after expression of juice from grapes became infested during storage, resulting in the production of 1. Because compound 1 is infrequently found in nature and has never been found in grape seeds, its presence may be considered a marker of an unwanted anaerobic bacterial process occurring during production. The antioxidant potential of 1 was determined by DPPH, ABTS, and FRAP (ferric reducing antioxidant power) assays and compared to the potential of the following compounds: phloroglucine, pyrogallol, gallic acid, catechin, and epicatechin. Furthermore, it was established that 1 significantly reduced guinea pig ileum contraction induced by histamine.

The Donor-Dependent and Colon-Region-Dependent Metabolism of (+)-Catechin by Colonic Microbiota in the Simulator of the Human Intestinal Microbial Ecosystem

“…Its molecular weight was also confirmed by UHPLC-MS analysis in positive and negative mode indicating protonated and deprotonated molecules at m / z 293 and 291, respectively. The product-ion spectrum for m / z 291 provided characteristic fragmentation ions at m / z 123, 247, 135 and 167, which is in agreement with previous reports [ 20 , 21 ]. The MS 2 fragmentation at 123.04 and 135.04 originated from the loss of C 8 H 9 O 4 and the combined loss of C 8 H 9 O 4 and H 2 O from the parent ion, respectively.…”

How Fermentation Affects the Antioxidant Properties of Cereals and Legumes

“…plantarum isolated from cheese, were found to cleave the heterocyclic ring of monomeric flavan-3-ols, giving rise to 1-(3′,4′-dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)propan-2-ol (3,4-diHPP-2-ol) [90]. This compound, which can be further degraded by the gut microbiota in several other substances, was recently studied for its antioxidant properties [91]. The authors found that 3,4-diHPP-2-ol had scavenging activity on ABTS and DPPH radicals higher than its precursor, as well as than other phenolic compounds.…”

A newly isolated intestinal bacterium involved in the C-ring cleavage of flavan-3-ol monomers and the antioxidant activity of the metabolites

“…This result is consistent with those previously reported in the literature. 51 In the FRAP assay, the ferric ion reducing capacity of EGC′ was 1.50-fold that of EGC. However, EGC and EGC′ showed no significant difference in DPPH and ABTS assays.…”