888-12-0Relevant articles and documents
Synthesis and Crystal Structure of Chalcone Derivatives and Their Effect on α-Glucosidase
Lin, Ping,Yin, Zhong-Ping,Wang, Meng,Liu, Jia,Yuan, En,Peng, Da-Yong,Nie, Xu-Liang,Shang-Guan, Xin-Chen
, p. 249 - 254 (2020)
Abstract: Five chalcone derivatives (E)-1-(2-(2-bromoethoxy)phenyl)-3-phenylprop-2-en-1-one(1), (E)-1-(2-(3-bromopropoxy)phenyl)-3-phenylprop-2-en-1-one(2),(E)-1-(2-(4-bromopropoxy)phenyl)-3-phenylprop-2-en-1-one(3),(E)-1-(2-(5-bromopropoxy)phenyl)-3-phenylprop-2-en-1-one(4),(E)-1-(2-(6-bromopropoxy)phenyl)-3-phenylprop-2-en-1-one(5) were synthesized and characterized by 1H NMR, HRMS. The crystalline structures of compounds 4 and 5 were further characterized by X-ray crystal diffraction. Among the five compounds, 1 and 2 showed inhibitory activity on α-glucosidase, but 4 and 5 increased the activity of α-glucosidase. Graphic Abstract: Five chalcone derivatives were synthesized and characterized by 1H MNR and HRMS. The crystalline structures of two compounds were further characterized by X-ray crystal diffraction. Two of the compounds have the ability to inhibit α-glucosidase, and two different compounds have the ability to promote α-glucosidase. [Figure not available: see fulltext.].
Stereoselective control in 1,3-dipolar cycloaddition of nitrones to substituted styrenes
Chiacchio, Ugo,Casuscelli, Franco,Corsaro, Antonino,Rescifina, Antonio,Romeo, Giovannni,Uccella, Nicola
, p. 6671 - 6680 (1994)
The stereochemistry of 1,3-dipolar cycloaddition of C-methyl-N-phenylnitrone 1 with substituted styrenes has been investigated. The presence of an hydroxyl function at the ortho position in the dipolarophile completely controls the stereochemical course of the reaction with the exclusive formation of cis cycloadduct 7. MNDO calculations help to rationalise the obtained results on the basis of an intermolecular hydrogen bonding, which leads to changes in the FMO properties so improving a stabilizing secondary orbital interaction in the E-endo transition state leading to cis isomer.
Control of the photoisomerization mode of carbon-carbon double bond by intramolecular hydrogen bond; one-way photoisomerization of 2′-hydroxychalcone induced by adiabatic intramolecular hydrogen atom transfer
Norikane, Yasuo,Itoh, Hiroki,Arai, Tatsuo
, p. 1094 - 1095 (2000)
To investigate the effect of intramolecular hydrogen bonding on the photoisomerization of carbon-carbon double bond, photoisomerization of 2′-hydroxychalcone has been studied. Based on the quantum yield measurements and laser flash photolysis studies, it
Ruthenium organometallics of chloro-substituted 2′-hydroxychalcones – A story of catecholase biomimetics beyond copper
Kahrovi?, Emira,Roca, Sun?ica,Vi?njevac, Aleksandar,Zahirovi?, Adnan
, (2021/05/26)
Four new organoruthenium(II) compounds of 2’-hydroxychalcones, differing in the position of the chloro substituent at chalcone moiety, were prepared by solution synthesis and characterized by chemical analysis, infrared and electron spectroscopy, mass spectrometry and 1D and 2D NMR spectroscopy, as biomimetic functional models of catechol oxidase. The molecular and crystal structures of three compounds were determined by single crystal X-ray diffraction. The organometallics are neutral species having piano-stool pseudo octahedral geometry with ruthenium(II) coordinated by η6-cymene, bidentate monobasic 2’-hydroxychalcone ligand, and chloride ion. The catecholase activity of new organometallics was investigated by electron spectroscopy in three solvents at three temperatures. The kinetic measurements were done under pseudo first order conditions and vmax, kcat, KM, TON, TOF, and Ea values are determined. Compounds (1) – (4) have solvent-dependent catecholase activity with activity decreasing in order ethanol > methanol ? acetonitrile. The highest kcat value and the lowest activation energy were found for the reaction catalyzed by organometallic (4), having a chloro substituent at the B ring of the chalcone ligand in the para position. The kcat values of 104 h?1 and 105 h?1 order at 297 K and 307 K, respectively classify these organometallics among the best artificial functional models of catechol oxidase. The results indicate that the catechol oxidation mediated by organometallics (1) – (4) proceeds via semiquinone radical formation.
Convenient synthesis of flavanone derivatives via oxa-Michael addition using catalytic amount of aqueous cesium fluoride
Miura, Motofumi,Shigematsu, Karin,Toriyama, Masaharu,Motohashi, Shigeyasu
supporting information, (2021/10/25)
A total of 36 flavanones, which included polycyclic aromatic and heterocyclic rings, were readily synthesized via oxa-Michael addition from the corresponding hydroxychalcones with a catalytic amount of aqueous cesium fluoride solution under mild conditions. This method could be applied to the scalable synthesis of eriodictyol as a known potent inhibitor of the SARS-CoV-2 spike protein.
Chapter Open for the Excited-State Intramolecular Thiol Proton Transfer in the Room-Temperature Solution
Chang, Chao-Che,Chen, Chao-Tsen,Chou, Pi-Tai,Huang, Chun-Hao,Li, Elise Y.,Liao, Yu-Chan,Liu, Yi-Hung,Liu, Zong-Ying,Meng, Fan-Yi,Wang, Chun-Hsiang
supporting information, p. 12715 - 12724 (2021/08/30)
We report here, for the first time, the experimental observation on the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton in room-temperature solution. This phenomenon is demonstrated by a derivative of 3-thiolflavone (3TF), namely, 2-(4-(diethylamino)phenyl)-3-mercapto-4H-chromen-4-one (3NTF), which possesses an - S - H···O= intramolecular H-bond (denoted by the dashed line) and has an S1 absorption at 383 nm. Upon photoexcitation, 3NTF exhibits a distinctly red emission maximized at 710 nm in cyclohexane with an anomalously large Stokes shift of 12 230 cm-1. Upon methylation on the thiol group, 3MeNTF, lacking the thiol proton, exhibits a normal Stokes-shifted emission at 472 nm. These, in combination with the computational approaches, lead to the conclusion of thiol-type ESIPT unambiguously. Further time-resolved study renders an unresolvable (180 fs) ESIPT rate for 3NTF, followed by a tautomer emission lifetime of 120 ps. In sharp contrast to 3NTF, both 3TF and 3-mercapto-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one (3FTF) are non-emissive. Detailed computational approaches indicate that all studied thiols undergo thermally favorable ESIPT. However, once forming the proton-transferred tautomer, the lone-pair electrons on the sulfur atom brings non-negligible nπ? contribution to the S1′ state (prime indicates the proton-transferred tautomer), for which the relaxation is dominated by the non-radiative deactivation. For 3NTF, the extension of π-electron delocalization by the diethylamino electron-donating group endows the S1′ state primarily in the ππ? configuration, exhibiting the prominent tautomer emission. The results open a new chapter in the field of ESIPT, covering the non-canonical sulfur intramolecular H-bond and its associated ESIPT at ambient temperature.
C3 amino-substituted chalcone derivative with selective adenosine rA1 receptor affinity in the micromolar range
Janse van Rensburg, Helena D.,Legoabe, Lesetja J.,Terre’Blanche, Gisella
, p. 1581 - 1605 (2020/11/20)
Abstract: To identify novel adenosine receptor (AR) ligands based on the chalcone scaffold, herein the synthesis, characterization and in vitro and in silico evaluation of 33 chalcones (15–36 and 37–41) and structurally related compounds (42–47) are reported. These compounds were characterized by radioligand binding and GTP shift assays to determine the degree and type of binding affinity, respectively, against rat (r) A1 and A2A ARs. The chalcone derivatives 24, 29, 37 and 38 possessed selective A1 affinity below 10?μM, and thus, are the most active compounds of the present series; compound 38 was the most potent selective A1 AR antagonist (Ki (r) = 1.6?μM). The structure–affinity relationships (SAR) revealed that the NH2-group at position C3 of ring A of the chalcone scaffold played a key role in affinity, and also, the Br-atom at position C3′ on benzylidene ring B. Upon in vitro and in silico evaluation, the novel C3 amino-substituted chalcone derivative 38—that contains an α,?-unsaturated carbonyl system and easily allows structural modification—may possibly be a synthon in future drug discovery. Graphic abstract: C3 amino-substituted chalcone derivative (38) with C3′ Br substitution on benzylidene ring B possesses selective adenosine rA1 receptor affinity in micromolar range.[Figure not available: see fulltext.]
Spectroscopic analysis by NMR, FT-Raman, ATR-FTIR, and UV-Vis, evaluation of antimicrobial activity, and in silico studies of chalcones derived from 2-hydroxyacetophenone
Xavier, Jayze da Cunha,de Almeida-Neto, Francisco W.Q.,Rocha, Janaína E.,Freitas, Thiago S.,Freitas, Priscila R.,de Araújo, Ana C.J.,da Silva, Priscila T.,Nogueira, Carlos E.S.,Bandeira, Paulo N.,Marinho, Márcia M.,Marinho, Emmanuel S.,Kumar, Nitin,Barreto, Ant?nio C.H.,Coutinho, Henrique D.M.,Juli?o, Murilo S.S.,dos Santos, Hélcio S.,Teixeira, Alexandre M.R.
, (2021/05/31)
Six 2’-hydroxychalcones were synthesized and characterized by NMR, FT-Raman, ATR-FTIR, and UV-Vis. These chalcones alone and in combination with the ciprofloxacin, penicillin, and erythromycin antibiotics were tested against multiresistant strains of Staphylococcus aureus. It was also verified by in vitro and in silico studeis the capacity of these chalcones to inhibit the NorA efflux pump. The MICs values of ciprofloxacin were reduced in the presence of all tested chalcones. For norfloxacin antibiotic, the chalcones A1, A4, A5 and A6 promoted the reduced in the MIC values. The A2 chalcone was the only one to reduce the MIC values when associated with penicillin. Any chalcones were not able to reduce MIC values when associated with erythromycin. These results indicate that the synergistic effects demonstrated for the synthesized chalcones were influenced by the introduction of a furanic ring (A1), a chlorine atom and a methoxy group at the C4 position (A2 and A4), a second double bond (A5), and a fluorine atom at the C2 position (A6). The ADMET analysis predicts that the chalcones A2, A3, A5 and A6 have easier cell permeation. The nucleophilic region makes the A5 chalcone capable of covalently bonding with plasma proteins, and the presence of oxygenated aromatic substitutions makes the chalcones A1 and A4 more water-soluble and consequently easier to excrete. On the other hand, the substitution of the methoxy group of the A4 chalcone makes it more susceptible to O-demethylation reactions by the CYP3A4 isoenzyme. The molecular docking revealed that all six chalcones could hinder the binding of norfloxacin to the NorA efflux pump.
Biocatalytic green alternative to existing hazardous reaction media: Synthesis of chalcone and flavone derivatives via the Claisen-Schmidt reaction at room temperature
Tamuli, Kashyap J.,Sahoo, Ranjan K.,Bordoloi, Manobjyoti
supporting information, p. 20956 - 20965 (2020/12/31)
Owing to the increasing amount of waste materials around the globe, the conversion of waste or secondary by-products to value-added products for various applications has gained significant interest. Herein, two novel agro-food waste products, Musa sp. 'Malbhog' peel ash (MMPA) and Musa Champa Hort. ex Hook. F. peel ash (MCPA) are used as catalysts to promote an inexpensive, efficient and eco-friendly carbon-carbon bond forming crossed aldol reaction at room temperature in solvent free conditions. Furthermore, the resulting products were subjected to reactions with these promoters in an oxygen atmosphere and led to the formation of novel flavone derivatives. Moreover, the used catalysts were properly characterized using different sophisticated analytical techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller analysis (BET), Raman spectroscopy, scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), transition electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) along with element detection using atomic absorption spectroscopy and ion chromatographic methods. These two approaches are metal free, as well as being devoid of any extra additives, co-catalysts, harsh conditions, the use of column chromatography for purification and result in a higher yield of the product within a short space of time. The catalytic abilities of the promoter were also examined to synthesize important bioactive molecules such as butein and apigenin at room temperature. With gram scale synthesis of the chalcone derivatives, the used catalysts (MMPA and MCPA) were further reused for five cycles and did not demonstrate any loss in catalytic activity.
Organocatalytic Approach for Assembling Flavanones via a Cascade 1,4-Conjugate Addition/oxa-Michael Addition between Propargylamines with Water
He, Xinwei,He, Xinwei,Xie, Mengqing,Li, Ruxue,Choy, Pui Ying,Tang, Qiang,Shang, Yongjia,Kwong, Fuk Yee
supporting information, p. 4306 - 4310 (2020/06/05)
A DBU-catalyzed one-pot cascade reaction of propargylamines and water for the synthesis of flavanones has been developed. This process proceeds via a sequence of 1,4-conjugate addition of water to alkynyl o-quinone methide (o-AQM), followed by the alkyne-allene isomerization and subsequent intramolecular oxa-Michael addition. This strategy provides a convenient method for accessing a broad range of flavanones in good to excellent yields with good functional-group tolerance, in particular, the reactive halo functional groups.
