Design, synthesis, and antimicrobial evaluation of 2‐aminothiazole derivatives bearing the 4‐aminoquinazoline moiety against plant pathogenic bacteria and fungi

Abstract

BACKGROUNDTo find more effective agricultural antibiotics, a class of new 2‐aminothiazole derivatives containing the 4‐aminoquinazoline moiety were synthesized and evaluated for their antimicrobial properties against phytopathogenic bacteria and fungi of agricultural importance.RESULTSAll the target compounds were fully characterized by 1H NMR, 13C NMR, and high‐resolution mass spectrometry. The bioassay results showed that compound F29 with a 2‐pyridinyl substituent exhibited an outstanding antibacterial effect against Xanthomonas oryzae pv. oryzicola (Xoc) in vitro, having an half‐maximal effective concentration (EC50) value as low as 2.0 μg/mL (over 30‐fold more effective than the commercialized agrobactericide bismerthiazol, with an EC50 value of 64.3 μg/mL). In addition, compound F8 with a 2‐fluorophenyl group demonstrated a good inhibitory activity toward the bacterium Xanthomonas axonopodis pv. citri (Xac), around twofold more active than bismerthiazol in terms of their EC50 values (22.8 versus 71.5 μg/mL). Interestingly, this compound also demonstrated a notable fungicidal effect against Phytophthora parasitica var. nicotianae, with an EC50 value largely comparable with that of the commercialized fungicide carbendazim. Finally, mechanistic studies revealed that compound F29 exerted its antibacterial effects by increasing the permeability of bacterial membranes, reducing the release of extracellular polysaccharides, and triggering morphological changes of bacterial cells.CONCLUSIONCompound F29 has promising potential as a lead compound for developing more efficient bactericides to fight against Xoc. © 2023 Society of Chemical Industry.

Exploring the latest trends in chemistry, structure, coordination, and diverse applications of 1-acyl-3-substituted thioureas: a comprehensive review

“…52 afford desired 2-aminothiazole derivatives (34F1-30) (Scheme 9). 53 Cyclization of pivaloyl thiourea (35) to 5-(tert-butyl)-N-(2,4dichlorophenyl)-1H-1,2,4-triazol-3-amine (36) was carried out by reacting pivaloyl thiourea (35) with hydrazine hydrate in ethanol at room temperature (Scheme 10). 54 Halo aroyltetrazoles (38a-l, 39a-c, 40a-c) were synthesized by Gunturu et al by addition of 50 mol% Fe 2 (SO 4 ) 3 $H 2 O, NaN 3 , and Et 3 N to the solution of N-benzoyl-N 0 -halophenyl thiourea (37a-l) in DMF at room temperature for 10 min (Scheme 11).…”

“…oryzicola (Xoc) with EC 50 value as low as 2.0 mg mL −1 (Scheme 9). 53 Muhammed et al synthesized acyl thiourea ligand (77) and its complexes with palladium to investigate its antibacterial potential against E. coli, S. sciuri, and S. aureus. Among compounds the complex [Pd(L) 2 (dppp)] showed the highest activity against S. aureus and S. sciuri with inhibition zones of 14.27 mm and 17.29 mm, respectively.…”

“…nicotianae have comparable activity with that of standard fungicides (Scheme 9). 53 6.1.3 Antituberculosis. Acyl thiourea derivatives synthesized by Poyrazet et al were investigated against the M. Tuberculosis H37Rv strain.…”

“…Wan et al synthesized a series of 2-aminothiazole derivatives ( 34F1-30 ), first of all reacting amine ( 31 ) with benzoyl isothiocyanate in dry THF furnished acyl thiourea derivative ( 32 ), followed by its hydrolysis using alkaline conditions to produce intermediate thiourea ( 33 ), which was further treated with different acetoaryl bromides in heated acetonitrile solution to afford desired 2-aminothiazole derivatives ( 34F1-30 ) (Scheme 9). 53…”