Endophytic Bacillus stercoris (VITSSSTJ4) an endophyte of Chaetomorpha antennina in the synthesis of lead molecule 1-(4-Acetamidoanilino)-3,7-dimethylbenzo[4,5]imidazo[1,2-a]pyridine-4-carbonitrile against bacterial pathogens.

Chaetomorpha antennina is a green alga and is known for its medicinal properties. Endophytes are microbes capable of synthesizing bioactive compounds which kills the pathogens without harming the host. The current study was aimed to detect the presence of endophytic bacteria that could inhibit bacterial human pathogens. The isolate VITSSSTJ4 produced secondary metabolites that restrained the development of Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli with a zone diameter of 19 ± 0.67, 13 ± 0.67 and 12 ± 0.67 mm respectively, in n-hexane extract. Additionally, SPE and UPLC were used to purify the extract and a peak was detected in UPLC at a retention time of 7.741 min. Further, FT-IR technique was employed to detect the functional groups such as C-O, O-H, N=C=O, C=C, C-H, O-H, and N-H. Gass Chromatography-Mass Spectrometry (GC-MS) confirmed molecular mass of the lead molecule to be 369.1638 g/mol and was identified to be 1-(4-Acetamidoanilino)-3,7-dimethylbenzo [4,5]imidazo[1,2-a]pyridine-4-carbonitrile. The effective isolate VITSSSTJ4 was found to be the closest neighbour of Bacillus stercoris in 16S rRNA gene sequencing, and the rod-shaped cell structure of VITSSSTJ4 was detected by scanning electron micrographs. Molecular docking revealed that the lead molecule had a substantial binding interaction with the methyltransferase component with a binding affinity of -7.7 kcal/mol.