In vitro and in silico studies of active phytochemical constituents isolated from Deverra tortuosa as anti-fish pathogens

The rapid growth of aquaculture production has led to an increase in disease outbreaks, and the misuse of antibiotics poses a threat to the developmental aquaculture industry. This study aims to isolate promising compounds from Deverra tortuosa (Desf.) DC and determine their bioactivity against some fish pathogens. The antimicrobial activities of the methanolic extract of D. tortuosa and four successively different fractions: hexane, chloroform, ethyl acetate, and butanol were carried out. The most potent and less polar fractions hexane and chloroform were qualitatively and quantitatively analyzed by using GC–MS. The minimum inhibitory concentration of these extracts showed the highest averages by using hexane and chloroform for bacteria (46.7 and 45.53 µg/ml) and fungi (47.73 and 47.33 µg/ml). By using supra-MIC of chloroform extract, Vibrio ordalli cell has non-uniformity of membranous structures and rupture of the periplasmic membrane that were observed on TEM. Molecular docking confirmed the mode of action of the identified compounds by the presence of good polar interaction with high binding energy of the characterized bioactive constituents with the recognized target enzymes involved in antimicrobial activities. In conclusion, chloroform extract of D. tortuosa contains various bioactive chemicals that can be useful as antimicrobial agents against fish diseases.