Synthesis, structure and structure–activity relationship analysis of caffeic acid amides as potential antimicrobials
摘要:
A series of caffeic acid amides 1-23 were synthesized and nine of which (13-17, 19-21 and 23) were reported for the first time. The chemical structures of these compounds were confirmed by means of H-1 NMR, ESI MS and elemental analyses. Compound 15 was determined by single-crystal X-ray diffraction analysis. All of the compounds were assayed for antibacterial (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens and Staphylococcus aureus) and antifungal (Aspergillus niger, Candida albicans and Trichophyton rubrum) activities by MTT method. Compounds 10-12, 15, 18 and 21 showed considerable antibacterial activities against B.subtilis with MICs of 795, 625, 389, 118, 312 and 155 mu g/mL, respectively. Structure-activity relationship analysts disclosed that caffeic acid amilides with electron-donating groups at p-position of benzene ring have better inhibitory activities.
A series of caffeic acid amides were designed, synthesized, and their synergistic activity with fluconazole against fluconazole-resistant Candida albicans was evaluated in vitro. The title caffeic acid amides 3-30 except 26 exhibited potent activity, and the subsequent SAR study was conducted. Compound 3, 5, 21, and 34c, at a concentration of 1.0 mu g/ml, decreased the MIC80 of fluconazole from 128.0 mu g/ml to 1.0-0.5 mu g/ml against the fluconazole-resistant C. albicans. This result suggests that the caffeic acid amides, as synergists, can sensitize drug-resistant fungi to fluconazole. The SAR study indicated that the dihydroxyl groups and the amido groups linking to phenyl or heterocyclic rings are the important pharmacophores of the caffeic acid amides. (C) 2014 Elsevier Ltd. All rights reserved.
Synthesis, structure and structure–activity relationship analysis of caffeic acid amides as potential antimicrobials
A series of caffeic acid amides 1-23 were synthesized and nine of which (13-17, 19-21 and 23) were reported for the first time. The chemical structures of these compounds were confirmed by means of H-1 NMR, ESI MS and elemental analyses. Compound 15 was determined by single-crystal X-ray diffraction analysis. All of the compounds were assayed for antibacterial (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens and Staphylococcus aureus) and antifungal (Aspergillus niger, Candida albicans and Trichophyton rubrum) activities by MTT method. Compounds 10-12, 15, 18 and 21 showed considerable antibacterial activities against B.subtilis with MICs of 795, 625, 389, 118, 312 and 155 mu g/mL, respectively. Structure-activity relationship analysts disclosed that caffeic acid amilides with electron-donating groups at p-position of benzene ring have better inhibitory activities.