Inhibitory potential of Syzygium aromaticum against Fusarium oxysporum f. sp. lycopersici: In-vitro analysis and molecular docking studies

Abstract

The antifungal potential of the extract of cloves (Syzygium aromaticum) was investigated in this study. The crude extracts of cloves and n-hexane, chloroform and n-butanol fractions were prepared. The antifungal activity of obtained fractions was studied at various concentrations ranging from 1.5 to 200.00 µg/mL. Thiophanate methyl (TM) was used as +ve control in this study. The fractions including methanolic, n-hexane, n-butanol, and chloroform significantly inhibited the growth of Fusarium oxysporum f.sp. lycopersici (FOL) ranging from 93.8 to 100 % when used at 200 µg/mL. The chloroform fraction showed 6.25 µg/mL MIC as compared to TM with 64 µg/mL MIC. GC/MS analysis showed that the chloroform fraction contained Eugenol, Phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl, 2,4-Di‑tert-butylphenol, n-Hexadecanoic acid, Phenol, and 2‑methoxy-4-(2-propenyl)- acetate. The findings of in-vitro antifungal analysis were further supported by molecular docking studies. Two virulence proteins of FOL i.e., global transcription regulator (SGE1) and DNA binding transcription factor (STE12) were docked with identified phytocompounds in the chloroform fraction by GC/MS analysis. Both of the receptors showed maximum binding affinities with 2-[2-(4-Phenyl-piperidin-1-yl)-ethyl]-isoindole-1,3‑dione (PED) (-12.054 kcal/mol) and 3,5-di‑tert-Butyl-4-hydroxyphenylpropionic acid (BHP) (-13.327 kcal/mol) respectively with strong hydrophilic/phobic interactions with active pocket residues. In conclusion, the chloroform fraction of S. aromaticum can be used to manage FOL.