•A serial of novel phosphoramidate derivatives of coumarin were designed.•These compounds exhibited moderate to excellent activity against chitin synthase.•These compounds showed good activity against the main pathogenic fungi in clinic.•The 7t was a non-competitive inhibitor with apparent Ki values of 0.096 mM.A series of novel phosphoramidate derivatives of coumarin have been designed and synthesized as chitin synthase (CHS) inhibitors. All the synthesized compounds have been screened for their chitin synthase inhibition activity and antimicrobial activity in vitro. The bioactive assay manifested that most of the target compounds exhibited good efficacy against CHS and a variety of clinically important fungal pathogens. In particular, compound 7t with IC50 of 0.08 mM against CHS displayed stronger efficiency than the reference Polyoxin B with IC50 of 0.16 mM. In addition, the apparent Ki values of compound 7t was 0.096 mM while the Km of Chitin synthase prepared from Candida tropicalis was 3.86 mM for UDP-N-acetylglucosamine, and the result of the Ki showed that the compounds was a non-competitive inhibitor of the CHS. As far as the antifungal activity is concerned, compounds 7o, 7r and 7t were highly active against Aspergillus flavus with MIC values in the range of 1 μg/mL to 2 μg/Ml while the results of antibacterial screening showed that these compounds have negligible actions to the tested bacteria. These results indicated that the design of these compounds as antifungal agents was rational.The title compounds were designed and synthesized as chitin synthase inhibitors.

A series of novel 1-methyl-3-substituted quinazoline-2,4-dione derivatives was designed, synthesized, and evaluated for their antimicrobial activities against six strains of bacteria and five fungi in vitro. The synthesized compounds were characterized by spectral methods. The bioactive assays showed that most of the compounds exhibited moderate antimicrobial activities against the tested strains.

A series of novel N-acyl substituted quinolin-2(1H)-one derivatives were synthesized and screened in vitro for their antibacterial and antifungal activities by disc diffusion method. All the compounds exhibited moderate to good antimicrobial activities, some of these compounds displayed comparable or better antibacterial or antifungal activities against some tested strains compared to the reference drugs Streptomycin and Fluconazole.N-Acyl substituted quinolin-2(1H)-one derivatives were synthesized and some of them displayed comparable or even better antibacterial and antifungal efficacy compared to reference drugs Streptomycin and Fluconazole.