51079-25-5Relevant articles and documents
Unexpected different chemoselectivity in the aerobic oxidation of methylated planar catechin and bent epicatechin derivatives catalysed by the Trametes villosa laccase/1-hydroxybenzotriazole system
Bernini, Roberta,Crisante, Fernanda,Gentili, Patrizia,Menta, Sergio,Morana, Fabio,Pierini, Marco
, p. 8183 - 8190 (2014)
Unreported methylated catechin and epicatechin derivatives 5 and 6 were synthesized by an oxa-Pictet-Spengler reaction. Catechin 5 shows the B and C rings coplanar because of the formation of a trans junction between the C ring and the newly generated six
Cinnamoyl glucosides of catechin and dimeric procyanidins from young leaves of Inga umbellifera (Fabaceae)
Lokvam, John,Coley, Phyllis D.,Kursar, Thomas A.
, p. 351 - 358 (2004)
The rapidly growing, nearly achlorophyllous, young leaves of Inga umbellifera express high concentrations of mono and dimeric 3-O-gluco-cinnamoyl catechin/epicatechin, rare forms of substituted flavan-3-ols. Here we present structures for five novel compo
TERPENOIDS AND A FLAVAN-3-OL FROM VIGUIERA QUINQUERADIATA
Delgado, Guillermo,Alvarez, Laura,Vivar, Alfonso Romo De
, p. 675 - 678 (1984)
The isolation is reported of the new natural products from Viguiera quinqueradiata, acetylleptocarpin and (2R,3S)-4'-hydroxy-3',5,7-tri-O-methyl-flavan-3-ol.The diterpenes 15α-angeloyloxy-ent-kaur-16-en-19-oic acid, 15α-tigloyloxy-ent-kaur-16-en-19-oic acid and the sesquiterpene lactones leptocarpin and budlein A were also found.Key Word Index - Viguiera quinqueradiata; Compositae; Heliantheae; sesquiterpene lactones; ent-kaurenoic acids; trans-flavan-3-ol.
Determination of absolute configuration of photo-degraded catechinopyranocyanidin A by modified Mosher's method
Oyama, Kin-ichi,Kondo, Tadao,Shimizu, Toshimichi,Yoshida, Kumi
, p. 556 - 563 (2020)
Catechinopyranocyanidins A and B (cpcA and cpcB) are two purple pigments present in the seed-coat of red adzuki bean, Vigna angularis, of which cpcA is the major pigment, containing two chiral carbons in the catechin part. Their absolute configurations we
Catechin Derivatives as Inhibitor of COVID-19 Main Protease (Mpro): Molecular Docking Studies Unveil an Opportunity Against CORONA
Arif, Muhammad Nouman
, p. 197 - 203 (2022/02/02)
Background: A newly emergent strain of coronavirus (COVID-19) has affected almost the whole of the world’s population. Currently, there is no specific vaccine or drug against COVID-19. Xu et al. (2020) built a homolog model of SARS-CoV-2 Mpro b
Synthesis and evaluation of stereoisomers of methylated catechin and epigallocatechin derivatives on modulating P-glycoprotein-mediated multidrug resistance in cancers
Chow, Larry M. C.,Li, Fu-xing,Li, Peng,Liu, Zhen,Sun, Wenqin,Wan, Sheng-biao,Wang, Bao-chao,Wang, Xing-kai,Wong, Iris L. K.
, (2021/10/04)
P-glycoprotein (P-gp; ABCB1)-mediated drug efflux causes multidrug resistance in cancer. Previous synthetic methylated epigallocatechin (EGC) possessed promising P-gp modulating activity. In order to further improve the potency, we have synthesized some novel stereoisomers of methylated epigallocatechin (EGC) and gallocatechin (GC) as well as epicatechin (EC) and catechin (C). The (2R, 3S)-trans-methylated C derivative 25 and the (2R, 3R)-cis-methylated EC derivative 31, both containing dimethyoxylation at ring B, tri-methoxylation at ring D and oxycarbonylphenylcarbamoyl linker between ring D and C3, are the most potent in reversing P-gp mediated drug resistance with EC50 ranged from 32 nM to 93 nM. They are non-toxic to fibroblast with IC50 > 100 μM. They can inhibit the P-gp mediated drug efflux and restore the intracellular drug concentration to a cytotoxic level. They do not downregulate surface P-gp protein level to enhance drug retention. They are specific for P-gp with no or low modulating activity towards MRP1- or BCRP-mediated drug resistance. In summary, methylated C 25 and EC 31 derivatives represent a new class of potent, specific and non-toxic P-gp modulator.
Site-Selective Alkoxylation of Benzylic C?H Bonds by Photoredox Catalysis
Lee, Byung Joo,DeGlopper, Kimberly S.,Yoon, Tehshik P.
supporting information, p. 197 - 202 (2019/11/26)
Methods that enable the direct C?H alkoxylation of complex organic molecules are significantly underdeveloped, particularly in comparison to analogous strategies for C?N and C?C bond formation. In particular, almost all methods for the incorporation of alcohols by C?H oxidation require the use of the alcohol component as a solvent or co-solvent. This condition limits the practical scope of these reactions to simple, inexpensive alcohols. Reported here is a photocatalytic protocol for the functionalization of benzylic C?H bonds with a wide range of oxygen nucleophiles. This strategy merges the photoredox activation of arenes with copper(II)-mediated oxidation of the resulting benzylic radicals, which enables the introduction of benzylic C?O bonds with high site selectivity, chemoselectivity, and functional-group tolerance using only two equivalents of the alcohol coupling partner. This method enables the late-stage introduction of complex alkoxy groups into bioactive molecules, providing a practical new tool with potential applications in synthesis and medicinal chemistry.
Bioactive Phytochemicals: Efficient Synthesis of Optically Active Substituted Flav-3-enes and Flav-3-en-3-o-R Derivatives
Achilonu, Matthew Chilaka,Sedibe, Moosa Mahmood,Shale, Karabo
, (2017/06/05)
The structural core of flavene (2-phenyl-2H-chromene) is commonly found in plant flavonoids, which exhibit a wide range of biological activities and diverse pharmacological profiles (e.g., antioxidant and anticancer activities). Flavonoids have attracted significant interest in medicinal and synthetic chemistry. Substituted flav-3-ene 13 was exclusively synthesized by the stereoselective elimination of the O-mesyl moiety on C-3 of 5,7,3′,4′-tetramethoxyflavan-3-mesylate 12 with 1,8-diazabicyclo[5.4.0]undec-7-ene. The reaction of 5,7,3′,4′-tetramethoxyflavan-3-one 15 with ytterbium trifluoromethanesulfonate in methanol afforded a novel 3-O-substituted flav-3-ene derivative (3,5,7,3′,4′-pentamethoxyflav-3-ene) 17. The reduction of 4-(1,3,5-trihydroxybenzene)-5,7,3′,4′-tetra-O-benzylflavan-3-one 19b with hydrogen afforded a new compound: 3-hydroxy-4-(1,3,5-trihydroxybenzene)-5,7,3′,4′-tetrahydroxyflavan-3-en-3-ol 21 in good yield (95%), while the acetylation of 19a and 21 afforded the expected novel flav-3-en-3-acetoxy derivatives 20 (92%) and 22 (90%), respectively.
Aged red wine pigments as a source of inspiration for organic synthesis - The cases of the color-stable pyranoflavylium and flavylium-(4→8)-flavan chromophores
Chassaing, Stefan,Isorez-Mahler, Géraldine,Kueny-Stotz, Marie,Brouillard, Raymond
, p. 3066 - 3078 (2015/05/04)
Two flavylium-based chromophores peculiar to aged red wine pigments are investigated from a synthetic viewpoint. The condensation between easy-to-prepare 5-hydroxy-4-methylflavylium salts and aldehydes, giving birth to color-stable pyranoflavylium pigments, further proves efficient and wide in scope. A set of some twenty structurally-related flavylium-based pigments has been prepared and structure:color relationships are discussed. Furthermore, the synthesis of the flavylium-(4→8)-flavan chromophore is achieved via a novel three-step sequence. The elaborated sequence starts with an iodine-magnesium exchange from an 8-iodinated flavan, thus generating a magnesiated species that then smoothly reacts with a flavone to furnish an adduct, that finally leads to the expected chromophore via dehydration.
Chemoselective C-4 aerobic oxidation of catechin derivatives catalyzed by the trametes villosa laccase/1-hydroxybenzotriazole system: Synthetic and mechanistic aspects
Bernini, Roberta,Crisante, Fernanda,Gentili, Patrizia,Morana, Fabio,Pierini, Marco,Piras, Monica
supporting information; experimental part, p. 820 - 832 (2011/04/23)
Catechin derivatives were oxidized in air in the presence of the Trametes villosa laccase/1-hydroxybenzotriazole (HBT) system in buffered water/1,4-dioxane as reactionmedium. The oxidation products, flavan- 3,4-diols and the corresponding C-4 ketones, are
