1849-59-8Relevant academic research and scientific papers
Stereoselective reduction of flavanones by marine-derived fungi
Birolli, Willian G.,Nitschke, Marcia,Porto, André Luiz M.,Santos, Darlisson de A.,de Matos, Iara L.
, (2021/08/13)
Biotransformation is an alternative with great potential to modify the structures of natural and synthetic flavonoids. Therefore, the bioreduction of synthetic halogenated flavanones employing marine-derived fungi was described, aiming the synthesis of flavan-4-ols 3a-g with high enantiomeric excesses (ee) of both cis- and trans-diastereoisomers (up to >99% ee). Ten strains were screened for reduction of flavanone 2a in liquid medium and in phosphate buffer solution. The most selective strains Cladosporium sp. CBMAI 1237 and Acremonium sp. CBMAI1676 were employed for reduction of flavanones 2a-g. The fungus Cladosporium sp. CBMAI 1237 presented yields of 72–87% with 0–64% ee cis and 0–30% ee trans with diastereoisomeric ratio (dr) from 52:48 to 64:36 (cis:trans). Whereas Acremonium sp. CBMAI 1676 resulted in 31% yield with 77–99% ee of the cis and 95–99% ee of the trans-diastereoisomers 3a-g with a dr from 54:46 to 96:4 (cis:trans). To our knowledge, this is the first report of the brominated flavon-4-ols 3e and 3f. The use of fungi, with emphasis for these marine-derived strains, is an interesting approach for enantioselective reduction of halogenated flavanones. Therefore, this strategy can be explored to obtain enantioenriched compounds with biological activities.
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.
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
, 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.
Synthesis, crystal structure and antitumour activity evaluation of 1H-thieno[2,3-c]chromen-4(2H)-one derivatives
Yu, Huchang,Li, Yan,Feng, Zhiyuan,Jiang, Hongwu,Zhao, Yinglan,Luo, Youfu,Huang, Wencai,Li, Zicheng
, p. 36 - 41 (2017/02/15)
A series of 1H-thieno[2,3-c]chromen-4(2H)-one derivatives were synthesised through Knoevenagel condensation of substituted flavanones with thiazolidine-2,4-dione in ethanol in the presence of piperidine. The mechanism of the reaction was proposed. All synthesised compounds were characterised by IR, 1H NMR, 13C NMR, HRMS, and elemental analysis. The structure of 2-(3-chlorophenyl)-1H-thieno[2,3-c]chromen-4(2H)-one was confirmed by a single crystal X-ray diffraction analysis. A preliminary antitumour screening showed that 2-(2-fluorophenyl)-1H-thieno [2,3-c]chromen-4(2H)-one had moderate to good activity against A549, BGC-823, HCT116 and MDA-MB-453 cancer cell lines, and 2-(3,4-dimethoxyphenyl)-1H-thieno[2,3-c]chromen-4(2H)-one displayed similar activity against these four kinds of cancer cells compared with the reference drug.
Enhanced reactivity and selectivity of asymmetric oxa-Michael addition of 2′-hydroxychalcones in carbon confined spaces
Shaikh, Melad,Atyam, Kiran Kumar,Sahu, Mahendra,Ranganath, Kalluri V. S.
supporting information, p. 6029 - 6032 (2017/07/10)
Carbon nanotubes (CNTs) are employed as nanoscale reaction vessels for the asymmetric oxa-Michael addition of 2′-hydroxychalcones. A systematic comparison of the catalytic activities of chiral phosphoric acid treated ferrite nanoparticles (chiral ferrites) has been studied for the synthesis of flavanones. Higher reactivity and selectivity with switching of enantiomers were observed when these chiral ferrites are inside the CNT channel.
Enantioselective biomimetic cyclization of 2′-hydroxychalcones to flavanones
Zhang, Yan-Lei,Wang, Yong-Qiang
supporting information, p. 3255 - 3258 (2014/06/09)
A new family of organocatalysts based on aminoquinoline and pyrrolidine have been developed and shown to catalyze the direct and highly enantioselective cyclization of 2′-hydroxychalcones in imitation of the natural process of chalcone cyclization. The straightforward synthetic process occurs under mild reaction conditions, tolerates moisture and air, and gives an enantiomeric excess up to 99%. This approach provides a facile and efficient access to chiral flavanones.
SAR studies of o-hydroxychalcones and their cyclized analogs and study them as novel inhibitors of cathepsin B and cathepsin H
Raghav,Garg
, p. 55 - 63 (2014/06/10)
Cathepsins have emerged as a potential target for anti-cancer drug development. In the present study, we have synthesized three structurally related series of flavanoids i.e., 2′-hydroxychalcones, flavanones and flavones and assayed in vitro to study their inhibitory potency against cathepsin B and H, promising drug candidate for cancer therapy. Enzyme kinetics studies were carried out in presence of these compounds after preliminary proteolytic studies on endogenous protein substrates. SAR studies suggested that open chain flavanoids were better inhibitors as compared to their cyclized analogs. The most potent inhibitors among the three series were nitro substituted compounds 1g, 2g and 3g with Ki values of ~6.18 × 10-8 M, 4.8 × 10-7 M and 7.85 × 10-7 M for cathepsin B and Ki values of ~2.8 × 10-7 M, 31.8 × 10-6 M and 33.7 × 10 -6 M for cathepsin H, respectively. The relationship between chalcone, flavanones and flavone structures interpreted by docking studies on cathepsin B and H also provided useful insights.
Highly efficient and green synthesis of flavanones and tetrahydroquinolones
Zheng, Xuxu,Jiang, Heyan,Xie, Jingjing,Yin, Zhongyi,Zhang, Haidong
, p. 1023 - 1029 (2013/03/13)
Highly efficient and green catalytic conversion of 2′-hydroxy and 2′-amino chalcones to flavanones and tetrahydroquinolones is reported herein. 2′-Hydroxy and 2′-amino chalcones can be almost completely converted to flavanones and tetrahydroquinolones in just 2 min in the presence of piperidine and KOH under room temperature. Liquiritigenin is also efficiently synthesized under similar conditions.
Hydromagnesite as an efficient recyclable heterogeneous solid base catalyst for the synthesis of flavanones, flavonols and 1,4-dihydropyridines in water
Rajesh, U. Chinna,Manohar, Sunny,Rawat, Diwan S.
, p. 3170 - 3178 (2013/12/04)
A form of hydromagnesite (HM) with flower-like thin-sheet morphology was synthesized by an environmentally benign approach using simple conventional heating at moderate temperature without using any template in water as medium. The versatility of this HM catalyst was studied in the synthesis of flavanones, flavonols and the multicomponent synthesis of 1,4-dihydropyridines in water. The recyclability of catalyst was studied for six times and there was no appreciable loss in its catalytic activity. Copyright
Sodium perborate tetrahydrate-mediated transformations of 2′-hydroxychalcones to flavanones, flavones, and 3′, 5′-diiodoflavone under mild, environmentally friendly conditions
Ganguly, Nemai C.,Chandra, Sumanta,Barik, Sujoy Kumar
, p. 1351 - 1361 (2013/05/09)
Sodium perborate tetrahydrate has been utilized as a nucleophilic catalyst for facile conversion of 2′-hydroxychalcones to flavanones in warm aqueous acetonitrile, and then these chalcones, upon oxidative cyclization in warm acetic acid with an excess of the same reagent, afforded flavones in acceptable yields. One-pot synthesis of 3′,5′-diiodoflavone has been accomplished by diacetoxyiodobenzene-catalyzed iodination of 2′-hydroxychalcone with tetra-n-butylammonium iodide in acetic acid in the presence of sodium perborate as a terminal oxidant.
