Efficient catalyst free green synthesis and in vitro antimicrobial, antioxidant and molecular docking studies of α-substituted aromatic/heteroaromatic aminomethylene bisphosphonates

Abstract

A new series of α-substituted aromatic/heteroaromatic amino bisphosphonates have been synthesized by the three component condensation of diversely substituted amines with dialkyl phosphites and triethyl orthoformate without catalyst and solvent under microwave irradiation conditions. All the synthesized compounds were screened for their in vitro antibacterial, antifungal, antioxidant activity and molecular docking studies. The results revealed that among the synthesized compounds 3e, 3f, 3i and 3j showed high antibacterial, antifungal activity when compared to the standard drugs. Computational docking studies were made on the test compounds to predict how several amino bisphosphonates bind to DNA ligase. The bioactive compounds 3e and 3f have stronger inhibiting activity on human DNA ligase enzyme when compared with standard antibiotic ciprofloxacin. The compounds 3e, 3f, 3i and 3j showed better DPPH, NO and H₂O₂ scavenging activity.

Graphical Abstract

Keywords:

• Amino methylene bisphosphonates
• antifungal
• antioxidant
• in vitro antibacterial
• molecular docking studies

Acknowledgments

The authors express thanks to Professor C. Devendranath Reddy, Department of Chemistry, Sri Venkateswara University, Tirupati, for his helpful discussions. One of the authors Dr. G. Mohan acknowledge DST-PURSE 2nd Phase Programme in S.V. University, Tirupati, funded by DST, New Delhi, India for providing instrumental analysis (File No. 17118-UGC-III(3)/DST-PURSE-2^nd phase/2017, dated 23/08/2018).

Additional information

Funding

The authors express thanks to University Grants Commission (UGC), New Delhi for funding and providing fellowship (BSR-RFSMS) to Mr. Shaik Mahammad Sadik. One of the authors Dr. G. Mohan acknowledge DST-PURSE 2nd Phase Programme in S.V. University, Tirupati, funded by DST, New Delhi, India for providing funding.