Design and synthesis of novel 1,3,2-benzoxazaphosphinine-2-one derivatives: an in vitro biological evaluation and in silico approaches

Abstract

A new class of benzoxazaphosphinine-2-one derivatives were synthesized by the reaction of 2-(3a,4,5,6,7,7a-hexahydro-1H-benzo[d]imidazol-2-yl)phenol with salicylic acid and thionyl chloride (SOCl₂) via three-step process, and were obtained in good to excellent yields (77–95%) The designed compounds were evaluated for their in vitro antioxidant, anti-fungal activities and in silico molecular docking. Amongst all, five compounds exhibited significant anti-fungal activity against F. oxysporum, A. niger and A. foetidus with MIC values displaying from 3.12 to 6.25 µg/mL correlated with standard drug Ketoconazole at 200 µg/mL. Furthermore, four compounds displayed promising antioxidant activity compared with the standard drugs butylated hydroxytoluene (BHT) and ascorbic acid in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide (NO) methods at 25, 50, 75 and 100 µg/mL. Molecular docking results disclosed that all the title compounds shown interesting binding modes with docking scores between −6.6 and −7.8 against the target 3MNG protein in comparison with standard drugs BHT (−5.1) and ascorbic acid (−5.5).

Graphical abstract

Keywords:

• Organophosphorus heterocycles
• 1,3,2-benzoxazaphosphinine-2-ones
• anti-fungal activity
• antioxidant activity
• molecular docking

Acknowledgments

Authors are grateful to Department of Chemistry, Sri Venkateswara University, Tirupati, Andhra Pradesh, India, for the constant support of this work.

Disclosure statement

There is no conflict of interest declared by the authors.