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Narendran Kandaswamy 한국고분자학회 2019 Macromolecular Research Vol.27 No.6
A series of three random copolyesters comprising biscoumarin and chalcone units as prime monomers, spaced with aliphatic alkyl chains of varying methylene units and 4,4′-oxydibenzoate, was synthesized and characterised by FTIR, NMR, TGA, DSC and XRD. The antimicrobial activity of the copolyesters was studied using Agar disc diffusion and broth dilution assay. The inhibitory effects of copolyesters were higher for Gram positive than Gram negative bacteria. All the copolyesters exhibited appreciable antimicrobial activity. In particular, copolyester 4c, poly(biscoumarin- 4,4’-oxydibenzoate-3-methoxychalcone) exhibited highest inhibition zone range of 19±0.39 mm for Bacillus subtilis, 20±0.51mm for Staphylococcus aureus and 20±0.22 mm for Staphylococcus epidermidis. Bacillus subtilis was more sensitive towards copolyester 4c exhibiting a minimum inhibitory concentration of 39.05 μg/mL. Chalcone coupled biscoumarin copolyester presented good antimicrobial activities comparable with those of standard antimicrobial agents, Chloramphenicol and Amphotericin-B. Thus the incorporation of biscoumarin and chalcone units in the polymer chain exhibit very good antimicrobial activity against gram positive bacterial and fungal strains.
Abolghasem Davoodnia 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.12
A novel catalytic synthesis of biscoumarins from 4-hydroxycoumarin and aromatic aldehydes has been developed. The reaction occurs in ethanol in the presence of tetrabutylammonium hexatungstate [TBA]_2[W_6O_19]as catalyst to give the corresponding products in high yields. This new approach has short reaction times, clean reaction profiles, and simple experimental and workup procedures. Moreover, the catalyst can be easily recovered by filtration and used at least three times with only slight reduction in its catalytic activity.
Davoodnia, Abolghasem Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.12
A novel catalytic synthesis of biscoumarins from 4-hydroxycoumarin and aromatic aldehydes has been developed. The reaction occurs in ethanol in the presence of tetrabutylammonium hexatungstate $[TBA]_2[W_6O_{19}]$ as catalyst to give the corresponding products in high yields. This new approach has short reaction times, clean reaction profiles, and simple experimental and workup procedures. Moreover, the catalyst can be easily recovered by filtration and used at least three times with only slight reduction in its catalytic activity.