104320-35-6Relevant articles and documents
Structural identification and distribution of proanthocyanidins in 13 different hops
Li, Hui-Jing,Deinzer, Max L.
, p. 4048 - 4056 (2006)
Ten newly isolated hop proanthocyanidin oligomers and flavan-3-ol monomers from 13 different hops have been identified as gallocatechin, gallocatechin-(4α→8)-catechin, gallocatechin-(4α→6)- catechin, catechin-(4α→8)-gallocatechin, catechin-(4α→6)- gallocatechin, afzelechin-(4α→8)-catechin, catechin-(4α→8) -catechin-(4α→8)-catechin, epicatechin-(4β→8)-epicatechin- (4β→8)-catechin, catechin-(4α→8)-gallocatechin- (4α→8)-catechin, and gallocatechin-(4α→8)-gallocatechin- (4α→8)-catechin, together with seven previously isolated oligomers, namely, catechin, epicatechin, epicatechin-(4β→8)-catechin, epicatechin-(4β→8)-epicatechin, catechin-(4α→8)-catechin, catechin-(4α→8)-epicatechin, and epicatechin-(4β→8)- catechin-(4α→8)-catechin. These compounds were subjected to acid-catalyzed degradation in the presence of phloroglucinol or by partial or complete acid-catalyzed degradation and reaction with benzyl mercaptan followed by desulfurization. The resultant adducts when compared to authentic samples by high-performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry and high-performance liquid chromatography-electrospray ionization tandem mass spectrometry served to identify the precursors. The composition of proanthocyanidins from 13 different hops was similar, but the concentration of individual compounds showed some differences, which indicated that hop proanthocyanidin profiles are affected by geographic origin and are variable depending on the cultivars.
Isolation and structure elucidation of tetrameric procyanidins from unripe apples (Malus pumila cv. Fuji) by NMR spectroscopy
Nakashima, Shohei,Oda, Chihiro,Masuda, Susumu,Tagashira, Motoyuki,Kanda, Tomomasa
, p. 144 - 152 (2012)
Procyanidins are plant secondary metabolites widely consumed and known to have various physiological functions, but their bioavailability and mechanism of action are still unclear especially for larger oligomers. One of the reasons is scarce information about the detailed structure of oligomeric procyanidins. As for apple, structures of procyanidin components larger than trimers are scarcely known. In this study, 11 tetrameric procyanidins including two known compounds were isolated from unripe apples (Malus pumila cv. Fuji) and identified by NMR spectroscopic analysis and phloroglucinol degradation. As a result, the detailed structural diversity of tetrameric procyanidins in apple was established.
Synthesis and ribonuclease A inhibition activity of resorcinol and phloroglucinol derivatives of catechin and epicatechin: Importance of hydroxyl groups
Dutta, Sansa,Basak, Amit,Dasgupta, Swagata
experimental part, p. 6538 - 6546 (2010/10/03)
The reported ribonuclease A inhibitory activity of the green tea extracts prompted us to synthesize novel catechin/epicatechin based conjugates with resorcinol and phloroglucinol with the aim to increase the number of phenolic OH groups. These are found to be more effective inhibitors of ribonuclease A as compared to catechin and epicatechin thus indicating the importance of number of phenolic OH groups for the inhibition of ribonucleolytic activity. Fluorescence studies have been carried out to evaluate the binding parameters. The protein-ligand docking studies are also performed to gain insight into the protein-polyphenols interactions. The epicatechin based polyphenols 1 and 2 also showed inhibition of angiogenin-induced angiogenesis, as determined by chorioallantoic membrane (CAM) assay.
