- Red fluorescence from tautomers of 2′-hydroxychalcones induced by intramolecular hydrogen atom transfer
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Tautomer fluorescence in the longer wavelength region at 600 nm produced by intramolecular hydrogen atom transfer was observed in several 2′-hydroxychalcones having an electron donating group at the para position of the phenyl ring. The quantum yield of tautomer fluorescence increased by 1000 times upon decreasing the temperature from room temperature to 77 K. The introduction of dendritic substituents also increased the intensity of the tautomer fluorescence. One can control the photochemical and photophysical properties of the olefins by introduction of intramolecular hydrogen bonding and photoinduced hydrogen atom transfer. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2009.
- Teshima, Takeshi,Takeishi, Madoka,Arai, Tatsuo
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- Synthesis, characterization, and antioxidant activity of Zn2+ and Cu2+ coordinated polyhydroxychalcone complexes
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Four new metal complexes [Cu(ISO)2], [Cu(BUT)2] and [Zn(ISO)2], [Zn(BUT)2] of the polyhydroxychalcones (isoliquiritigenin and butein) are synthesized, structurally characterized and their antioxidant activity is investigated. The formation of the complexes [Cu(ISO)2] and [Zn(ISO)2] is followed by Job’s plot using NMR titration. The resulting compounds are characterized by mass spectrometry, IR spectroscopy, and elemental analysis. Studies on the radical scavenging activity are performed using DPPH as substrate. The results showed that the antioxidant activities of isoliquiritigenin and butein are enhanced after binding to copper or zinc. Graphical abstract: [Figure not available: see fulltext.]
- Sulpizio, Chiara,Müller, Simon T. R.,Zhang, Qi,Brecker, Lothar,Rompel, Annette
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p. 1871 - 1881
(2016/10/22)
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- Synthesis and antibacterial activity of chalcones bearing prenyl or geranyl groups from Angelica keiskei
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Chalcones bearing prenyl or geranyl groups from Angelica keiskei, such as 4-hydroxyderricin (1a), xanthoangelol (1e), xanthoangelol F (1f), xanthoangelol H (2), deoxyxanthoangelol H (3), and deoxydihydroxanthoangelol H (4) and their derivatives were synthesized. From the evaluation of antibacterial activity of the synthesized chalcones, 1a, isobavachalcone (1b), 1e, 1f, bavachalcone (5a), and broussochalcone B (5b) were found to inhibit Gram-positive bacteria.
- Sugamoto, Kazuhiro,Matsusita, Yoh-Ichi,Matsui, Kana,Kurogi, Chiaki,Matsui, Takanao
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p. 5346 - 5359
(2011/08/04)
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- Anti-ulcer agent comprising chalcone derivative as effective ingredient and novel chalcone derivative
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The present invention relates to an anti-ulcer agent comprising a compound represented by the following general formula I as the effective ingredient, and a novel chalcone derivative included in the compound represented by this general formula I: STR1 wherein X and Y independently stand for a hydrogen atom or together form a single bond, R1 stands for a hydroxyl group, an acetoxy group, a carboxymethoxy group or a methoxycarbonylmethoxy group, R2 stands for a hydrogen atom, an isoprenyl group, isopentyl group or a propyl group, R3 stands for hydroxyl group or a methoxy group, R4 stands for a hydrogen atom, a hydroxyl group or a methoxy group, R5 stands for a hydrogen atom, a hydroxyl group, a methoxy group or an isopentyl group, R6 stands for a hydroxyl group, a methoxy group or a carboxymethoxy group, and R7 stands for a hydrogen atom or a methoxy group.
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- CONVERSION OF 2'-HYDROXYCHALCONES TO FLAVANONES CATALYZED BY COBALT SHIFF BASE COMPLEX
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Co(salpr) catalyzes the conversion of 2'-hydroxychalcones to flavanones in methanol under oxygen.Base catalysis by Co(salpr) (OH) produced in situ is responsible for the reaction, which is found to proceed reversibly.
- Maruyama, Kazushige,Tamanaka, Kimihiro,Nishinaga, Akira,Inada, Akira,Nakanishi, Tsutomu
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p. 4145 - 4148
(2007/10/02)
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- New Syntheses of 4',7-Dihydroxy-6,8-di-C-prenylflavanone, Bavachin, Isobavachin and Related Compounds
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The titel compounds have been synthesised by nuclear prenylation of 4',7-dihydroxyflavanone(liquiritigenin, III), Cyclodehydrogenation of bavachin and isobavachin with DDQ yields the chromenoflavanones (VIII) and (X) respectively which on dehydrogenation
- Krishnamurti, M.,Parthasarathi, J.
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p. 247 - 248
(2007/10/02)
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