Investigation on 4-amino-5-substituent-1,2,4-triazole-3-thione Schiff bases an antifungal drug by characterization (spectroscopic, XRD), biological activities, molecular docking studies and electrostatic potential (ESP)

Four novel Schiff bases 4-(2,4-dinitrobenzylideneamino)-5-m-tolyl-2H-1,2,4-triazole-3(4H)-thione) (F-1), 4-(2,4-dinitrobenzylideneamino)-5-(2-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione) (F-2), 4-(2,4-dinitrobenzylideneamino)-5-(3-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione) (F-3) and 4-(2,4-dinitrobenzylideneamino)-5-(4-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione) (F-4) were prepared as new antifungal compounds contributing 4-Amino-5-Substituent-1,2,4-Triazole-3-Thione and 2,4-dinitrobenzaldehyde via a condensation reaction under the mild conditions with excellent yields. The structures of compounds were characterized by elemental analysis (EA), FT-IR, H-1 NMR, C-13 NMR spectra and X-ray analysis. In addition, the compounds were screened for in vitro biological activity, and the bioassay results indicated that the newly synthesized compounds showed different in vitro antifungal activities against five plant fungi. Particularly, compound F-3 (EC50 = 11.16 mg/L) was found to be the most active respectively against Wheat gibberellic, even more effective than Fluconazole (EC50 = 16.03 mg/L). The active compounds were further evaluated for enzyme inhibition efficacy against the receptor CYP51 by docking. Meanwhile, an explicit surface analysis on compounds were carried out theoretically using the wave function analyzer (Multiwfn 3.4.1 software) in order to study the reactivity of the compounds. (C) 2019 Published by Elsevier B.V.