7295-85-4Relevant academic research and scientific papers
11-β-hydroxysterols as possible endogenous stimulators of mitochondrial biogenesis as inferred from epicatechin molecular mimicry
Dugar, Sundeep,Villarreal, Francisco,Hollinger, Frank H.,Mahajan, Dinesh,Ramirez-Sanchez, Israel,Moreno-Ulloa, Aldo,Ceballos, Guillermo,Schreiner, George
, (2019/11/28)
Currently, there is great interest in identifying endogenous (i.e. physiological) stimulators of mitochondrial biogenesis (MB), in particular, those that may mediate the effects of exercise. The molecular size of the cacao flavanols (epicatechin and catechin) highly resembles that of sterols and epicatechin has been reported to activate cells surface receptors leading to the stimulation of MB in endothelial and skeletal muscle cells translating into enhanced exercise capacity. We therefore hypothesize, that epicatechin may be acting as a structural mimic of an as yet unknown sterol capable of stimulating MB. We developed a new synthetic process for obtaining enantiomerically pure preparations of (-)-epicatechin and (+)-epicatechin. Applying spatial analytics and molecular modeling, we found that the two isoforms of epicatechin, (-) and (+), have a structural resemblance to 11-β-hydroxypregnenolone, a sterol with no previously described biological activity. As reported in this proof-of-concept study performed in primary cultures of endothelial and muscle cells, 11-β-hydroxypregnenolone is one of the most potent inducers of MB as significant activity can be detected at femtomolar levels. The relative potency of (-)/(+)-epicatechin isoforms and on inducing MB correlates with their degree of spatial homology towards the 11-β-hydroxypregnenolone. On the basis of these results, the detailed in vivo characterization of the potential for these sterols to act as endogenous modulators of MB is warranted.
A catechin preparation method of compound (by machine translation)
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, (2017/02/23)
The invention relates to a method for preparing a catechin compound. The method comprises the following steps: by taking 2,4,6-trihydroxy acetophenone and p-hydroxy benzaldehyde as raw materials, carrying out condensation reaction, restored deoxidation, cyclization reaction of acid catalysis, so as to obtain the catechin compound. The invention also provides a technology for producing the catechin compound. In the synthesis process of an immediate 9, reduction is carried out by using sodium borohydride which is catalyzed by a lewis acid, so that side reaction caused by double bond transfer is greatly reduced while a highly toxic reagent osmium tetroxide is replaced with hydrogen peroxide oxidation.
NOVEL APPROACH FOR SYNTHESIS OF CATECHINS
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, (2016/01/15)
A process for synthesis of enatiomerically pure or enatiomerically enriched or racemic mixture of (+and/or?) epicatechin echm and its intermediates, comprising the steps of: (i) obtaining penta-protected quercetin; (ii) reducing the penta-protected quercetin obtained from step (i); (iii) optionally deprotecting the compound of step (ii); (iv) reducing the compound obtained from step (ii) or step (iii) in the presence of a chiral/achiral reducing agent to obtain a chiral intermediate; (v) deprotecting and/or hydrogenation of the chiral intermediate obtained from step (iv) to obtain (?)-epicatechin; (vi) optionally simultaneously deprotecting and by drogenation of the compound obtained from step (ii) to obtain racemic epicatechin.
NOVEL PROCESS FOR SYNTHESIS OF POLYPHENOLS
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Paragraph 0150; 0151; 0152; 0153, (2014/02/16)
The present invention provides synthetic processes for preparing racemic and/or optically pure epicatechin, epigallocatechin and related polyphenols as such or as their variously functionalized derivatives. A principle objective of the disclosure is to provide a new and useful method of synthesis to obtain polyphenols in isomerically pure and/or racemic forms.
A NOVEL PROCESS FOR SYNTHESIS OF POLYPHENOLS
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Page/Page column 31, (2012/08/08)
The present invention provides synthetic processes for preparing racemic and/or optically pure epicatechin, epigallocatechin and related polyphenols as such or as their variously functionalized derivatives.
High molecular weight persimmon (Diospyros kaki L.) proanthocyanidin: A highly galloylated, a-linked tannin with an unusual flavonol terminal unit, myricetin
Li, Chunmei,Leverence, Rachael,Trombley, John D.,Xu, Shufen,Yang, Jie,Tian, Yan,Reed, Jess D.,Hagerman, Ann E.
experimental part, p. 9033 - 9042 (2011/05/05)
MALDI-TOF MS suggested that the high molecular weight proanthocyanidin (condensed tannin) from persimmon (Diospyros kaki L.) pulp comprised a heteropolyflavanol series with flavan-3-O-galloylated extenders, flavan-3-ol and flavonol terminal units, and A-type interflavan linkages. Thiolysis-HPLC-ESI-MS with DAD, electrochemical, and ESI-MS detection confirmed a previously unreported terminal unit, the flavonol myricetin, in addition to the typical flavan-3-ols catechin and epigallocatechin gallate. The extender units were epicatechin, epigallocatechin, (epi)gallocatechin-3-O-gallate, and (epi)catechin-3-O-gallate. The crude tannin had a high prodelphinidin content (65%) and a high degree of 3-O-galloylation (72%). The material was fractionated on Toyopearl TSK-HW-50-F to yield fractions distinguished by degree of polymerization (DP). Thiolysis suggested that the persimmon tannin was composed of polymers ranging from 7 to 20 kDa (DP 19-47), but sizes estimated by GPC were 50-70% smaller. The crude material was chemically degraded with acid to yield products that were amenable to NMR and ESI-MS analysis, which were used to establish for the first time that persimmon tannin has a mixture of B-type and A-type linkages. 2010 American Chemical Society.
Reduction potentials of flavonoid and model phenoxyl radicals. Which ring in flavonoids is responsible for antioxidant activity?
Jovanovic, Slobodan V.,Steenken, Steen,Hara, Yukihiko,Simic, Michael G.
, p. 2497 - 2504 (2007/10/03)
Model phenoxyl and more complex flavonoid radicals were generated by azide radical induced one-electron oxidation in aqueous solutions. Spectral, acid-base and redox properties of the radicals were investigated by the pulse radiolysis technique. The physicochemical characteristics of the flavonoid radicals closely match those of the ring with the lower reduction potential. In flavonoids which have a 3,5-dihydroxyanisole (catechins), or a 2,4-dihydroxyacetophenone (hesperidin, rutin, quercetin)-like A ring and a catechol- or 2-methoxyphenol-like B ring, the antioxidant active moiety is clearly the B ring [reduction potential difference between the model phenoxyls is ΔE(A-B ring models) > 0.1 V]. In galangin, where the B ring is unsubstituted phenyl, the antioxidant active moiety is the A ring. Even though the A ring is not a good electron donor, E7, > 0.8/NHE V, it can still scavenge alkyl peroxyl radicals, E7, = 1.06 V, and the Superoxide radical, E7 > 1.06 V. Quercetin is the best electron donor of all investigated flavonoids (measured E10.8 = 0.09 V, and calculated E7 = 0.33 V). The favourable electron-donating properties originate from the electron donating O-3 hydroxy group in the C ring, which is conjugated to the catechol (B ring) radical through the 2,3-double bond. The conjugation of the A and B rings is apparently minimal, amounting to less than 2.5% of the substituent effect in either direction. Thus, neglecting the acid-base equilibria of the A ring, and using those of the B ring and the measured values of the reduction potentials at pH 3,7 and 13.5, the pH dependence of the reduction potentials of the flavonoid radicals can be calculated. In neutral and slightly alkaline media (pH 7-9), all investigated flavonoids are inferior electron donors to ascorbate. Quercetin, E7 = 0.33 V, and gallocatechins, E7 = 0.43 V, can reduce vitamin E radicals (assuming the same reduction potential as Trolox C radicals, E7 = 0.48 V). Since all investigated flavonoid radicals have reduction potentials lower than E7 = 1.06 V of alkyl peroxyl radicals, the parent flavonoids qualify as chain-breaking antioxidants in any oxidation process mediated by these radicals.
IODINATION AND DEUTERATION OF CATECHIN DERIVATIVES
Kiehlmann, E.,Lehto, N.,Cherniwchan, D.
, p. 2431 - 2439 (2007/10/02)
The preparation and 1H and 13C nuclear magnetic reonance spectra of ten monoiodocatechin derivatives are described.The iodination of catechin with N-iodosuccinimide (NIS) takes place regiospecifically at C-6 in acetone but preferentially at C-8 in dimethylformamide; both products can be derivatized at oxygen in alkali medium but lose iodine in the presence of acid. 3',4',5,7,-Tetra-O-methylcatechin reacts with NIS regiospecifically at C-8 while catechin pentaacetate resists iodination.The debromination of 6-bromo- and 6,8-dibromocatechin with sodium sulfite in CD3CN/D2O is accompained by H/D-exchange at C-6 and C-8.The synthesis of catechin pentaacetate from partially deuterated catechin and its conversion to terta-O-methylcatechin proceed without H/D-exchange and permit distinction between the H-6 and H-8 chemical shifts.
DEOXYGENATION OF ALDEHYDES AND KETONES WITH SODIUM CYANOBOROHYDRIDE
Elliger, Carl A.
, p. 1315 - 1324 (2007/10/02)
Treatment of hydroxy-substituted aromatic aldehydes and ketones with sodium cyanoborohydride yields the corresponding methylene compounds under conditions which favor intermediate carbonium ion formation.
Physico-Chemical Studies of Catechins and Epicatechins
Singh, Joginder,Ralhan, N. K.,Pant, T. K.
, p. 1044 - 1047 (2007/10/02)
The physico-chemical properties of (-)-epicatechin, (+)-catechin have been found to be at variance from those reported in literature, and have been corrected after confirmation, by elemental analysis, TGA etc.A quasiracenate (C15H14O6*3H2O) of (-)-epicatechin and (+)-catechin (1 : 1) has also been isolated and characterised.
