57765-66-9Relevant articles and documents
Enzymatic conversion of flavonoids using bacterial chalcone isomerase and enoate reductase
Gall, Mechthild,Thomsen, Maren,Peters, Christin,Pavlidis, Ioannis V.,Jonczyk, Patrick,Grunert, Philipp P.,Beutel, Sascha,Scheper, Thomas,Gross, Egon,Backes, Michael,Geissler, Torsten,Ley, Jakob P.,Hilmer, Jens-Michael,Krammer, Gerhard,Palm, Gottfried J.,Hinrichs, Winfried,Bornscheuer, Uwe T.
, p. 1439 - 1442 (2014)
Flavonoids are a large group of plant secondary metabolites with a variety of biological properties and are therefore of interest to many scientists, as they can lead to industrially interesting intermediates. The anaerobic gut bacterium Eubacterium ramulus can catabolize flavonoids, but until now, the pathway has not been experimentally confirmed. In the present work, a chalcone isomerase (CHI) and an enoate reductase (ERED) could be identified through whole genome sequencing and gene motif search. These two enzymes were successfully cloned and expressed in Escherichia coli in their active form, even under aerobic conditions. The catabolic pathway of E. ramulus was confirmed by biotransformations of flavanones into dihydrochalcones. The engineered E. coli strain that expresses both enzymes was used for the conversion of several flavanones, underlining the applicability of this biocatalytic cascade reaction.
Examination of the phenolic profile and antioxidant activity of the leaves of the australian native plant smilax glyciphylla
Huang, An-Cheng,Wilde, Amelie,Ebmeyer, Johanna,Skouroumounis, George K.,Taylor, Dennis K.
, p. 1930 - 1936 (2013/11/19)
Together with the sweet principle component glycyphyllin A (3), seven phenolic compounds including two new dihydrochalcone rhamnopyranosides, glycyphyllin B (1) and glycyphyllin C (2), and five known flavonoids, catechin (4), kaempferol-3-O-β-d-glucopyranoside (5), quercetin-3-O-β-d- glucopyranoside (6), kaempferol-3-O-β-neohesperidoside (7), and 2R,3R-dihydrokaempferol-3-O-β-d-glucopyranoside (8), have been isolated from the ethanolic extract of the leaves of Smilax glyciphylla for the first time. The structures of these compounds were characterized by spectroscopic methods including UV, MS, and 1D and 2D NMR. In vitro antioxidant capacity tests employing FRAP and DPPH assays indicated that 1, 4, and 6 exhibited potent antioxidant activity and are the key phenolics responsible for the antioxidant activity of the leaf extract of S. glyciphylla.
Dihydrochalcones: Evaluation as novel radical scavenging antioxidants
Nakamura, Yoshimasa,Watanabe, Shigeo,Miyake, Nobuyuki,Kohno, Hiroyuki,Osawa, Toshihiko
, p. 3309 - 3312 (2007/10/03)
Dihydrochalcones are a family of bicyclic flavonoids, defined by the presence of two benzene rings joined by a saturated three carbon bridge. In the present study, we systematically examined the antioxidant activities of dihydrochalcones against the stable free radical (1,1-diphenyl-2-picrylhydrazyl) and lipid peroxidation in the erythrocyte membrane. All dihydrochalcones exhibited higher antioxidant activities than the corresponding flavanones. The 1H NMR analysis indicated that the active dihydrochalcone has a time-averaged conformation in which the aromatic A ring is orthogonal to the carbonyl group, while the inactive dihydrochalcone such as 2′-O-methyl-phloretin has a strongly hydrogen-bonded phenolic hydroxyl group, suggestive of a coplanar conformation. A hydroxyl group at the 2′-position of the dihydrochalcone A ring, newly formed by reduction of the flavanone C ring, is an essential pharmacophore for its radical scavenging potential.
