69912-75-0Relevant academic research and scientific papers
Synthesis and quantitative analysis of plasma-targeted metabolites of catechin and epicatechin
Blount, Jack W.,Redan, Benjamin W.,Ferruzzi, Mario G.,Reuhs, Bradley L.,Cooper, Bruce R.,Harwood, John S.,Shulaev, Vladimir,Pasinetti, Giulio,Dixon, Richard A.
, p. 2233 - 2240 (2015/03/14)
Grape seed polyphenolic extract (GSPE) rich in the flavan-3-ols (+)-catechin and (-)-epicatechin beneficially modulates Alzheimers Disease phenotypes in animal models. The parent molecules in the extract are converted to a series of methylated and glucuronidated derivatives. To fully characterize these metabolites and establish a robust quantitative assay of their levels in biological fluids, we have implemented a partial synthetic approach utilizing chemical methylation followed by enzymatic glucuronidation. Liquid chromatography/time-of-flight mass spectrometry (LC-TOF-MS) and nuclear magnetic resonance (NMR) spectroscopy were used to assign unequivocal structures to the compounds. An analytical method using solid-phase extraction and LC-MS/MS in selective reaction monitoring mode (SRM) was validated for their quantitation in plasma. These studies provide a basis for improvements in future work on the bioavailability, metabolism, and mechanism of action of metabolites derived from dietary flavan-3-ols in a range of interventions.
Preparation and characterization of Catechin sulfates, glucuronides, and methylethers with metabolic interest
Gonzalez-Manzano, Susana,Gonzalez-Paramas, Ana,Santos-Buelga, Celestino,Duenas, Montserrat
experimental part, p. 1231 - 1238 (2010/06/14)
Catechins are major polyphenols in many plant foods that have been related to health promotion. In the human organism they are largely metabolized to different conjugates (sulfates, glucuronides, and methylethers), which are further found in plasma and would contribute to the biological effects associated with the intake of the parent compounds. Circulating metabolites are likely to possess biological properties different from those of the original compounds, and therefore, it is important to evaluate their activity, for which sufficient amounts of them are required that cannot be obtained by isolation from biological fluids. This paper describes the preparation of the methyl, sulfate, and glucuronide derivatives of catechins using different chemical syntheses and their characterization by HPLC-DAD-ESI/MS. MS2 fragmentation of the compounds was also described that allowed the determination of the location of the different substituents on the catechin aglycones. The procedures optimized allowed the preparation of (epi)catechin sulfates, glucuronides, and methylethers conjugated at positions 3' and 4', as well as the sulfates at positions 5 and 7 with satisfactory yields for their further isolation by semipreparative-HPLC in view of their use in in vitro/ex vivo assays.
Enzymatic O-methylation of flavanols changes lag time, propagation rate, and total oxidation during in vitro model triacylglycerol-rich lipoprotein oxidation
Yu, Jun,Smith, Gabe,Gross, Heidrun B.,Hansen, Robert J.,Levenberg, John,Walzem, Rosemary L.
, p. 8403 - 8408 (2007/10/03)
3′-O-Methyl derivatives of flavan-3-ols, (+)-catechin (C), (-)-epicatechin (EC), and (-)-catechin gallate (CG) were prepared enzymatically. Hexanal (EC and CG family, 5 mmol/L) and conjugated diene (C and EC family, 0.25-10 mmol/L) formation following CuS
An efficient synthesis of the four mono methylated isomers of (+)-catechin including the major metabolites and of some dimethylated and trimethylated analogues through selective protection of the catechol ring
Cren-Olive, Cecile,Lebrun, Stephane,Rolando, Christian
, p. 821 - 830 (2007/10/03)
The four monomethylated isomers of (+)-catechin in positions 3′, 4′, 5 and 7, two dimethylated derivatives, the 5,7-dimethylcatechin and the 3′, 4′-dimethylcatechin and two trimethylated isomers of (+)-catechin in positions 3′, 5, 7 and 4′, 5, 7 were synthesized by a new method based on successive and selective protections of the various phenol functions present on (+)-catechin. The key step was the selective protection of the catechol ring with dichlorodiphenylmethane and di-tert-butyldichlorosilane.
Oligomeric flavanoids. Part 7. Novel base-catalysed pyran rearrangements of procyanidins
Steynberg, Jan P.,Bezuidenhoudt, Barend C. B.,Burger, Johann F. W.,Young, Desmond A.,Ferreira, Daneel
, p. 203 - 208 (2007/10/02)
Procyanidin B-3 (1) is subject to readily occurring c-ring isomerizations in NaHCO3-Na2CO3 buffer solution to form a novel 8,9-cis-9,10-trans-3,4,9,10-tetrahydro-2H,8H-pyrano[2,3-h;]chromene (3) and a series of 2,3-cis-3,4-trans-4-aryl-2-flavanylbenzopyrans (6), (9), and (12) in which the C-2 pyrocatechol and C-4 ( + )-catechin moieties are interchanged relative to their positions in the biflavanoid (1). These compounds presumably originate via 1,3-aryl migrations in intermediate quinone-methides with concomitant inversion of the absolute configuration at C-3. The lability of the interflavanyl bond at alkaline pH is reflected by the presence of considerable quantities of (+)-catechin as well as high-molecular-mass analogues of precursor (1).
OLIGOMERIC FLAVANOIDS. PART 3. STRUCTURE AND SYNTHESIS OF PHLOBATANNINS RELATED TO (-)-FISETINIDOL-(4α,6)- AND (4α,8)-(+)-CATECHIN PROFISETINIDINS
Steynberg, Jan P.,Burger, Johann F. W.,Young, Desmond A.,Brandt, Edward, V.,Steenkamp, Jacobus A.,Ferreira, Daneel
, p. 3323 - 3330 (2007/10/02)
Several members of the novel class of natural 'phlobaphene' condensed tannins, representing the products of c-ring isomerization of 2,3-trans-3,4-trans-(-)-fisetinidol units present in (4,6)- and (4,8)-biflavanoid profisetinidins, have been charcterized b
