Sulfonamide hybrid schiff bases of anthranilic acid: Synthesis, characterization and their biological potential Naghmana Kausar a , Shahzad Muratza a, * , Muhammad Asam Raza a , Hummera Rafique a , Muhammad Nadeem Arshad b, c , Ataf Ali Altaf a , Abdullah M. Asiri b, c, ** , Syed Salman Shafqat d , Syed Rizwan Shafqat e a Department of Chemistry, University of Gujrat, 50700, Gujrat, Pakistan b Chemistry Department, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah, 21589, Saudi Arabia c Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, P. O. Box 80203, Jeddah, 21589, Saudi Arabia d Department of Chemistry, University of Management and Technology, Sialkot, Pakistan e University Malaysia Sarwak (Unimas), Malaysia article info Article history: Received 15 November 2018 Received in revised form 13 February 2019 Accepted 14 February 2019 Available online 21 February 2019 Keywords: Sulfonamide Mental disorders Docking studies Hydrazine Methyl anthranilate DPPH abstract In the present work, the novel Schiff bases (03e20) of 4-chloro-N-[2-(hydrazinocarbonyl) phenyl]ben- zenesulfonamide (02) were synthesized by reacting it with various aldehydes. 4-Chloro-N-[2-(hydrazi- nocarbonyl) phenyl]benzenesulfonamide (02) was synthesized by reacting methyl 2-{[(4-chlorophenyl) sulfonyl]amino}benzoate (01) with hydrazine. All synthesized compounds (01e20) were characterized by using FTIR, NMR and Mass spectrometry and by single crystal X-ray diffraction (XRD) analysis tech- niques. The synthesized compounds were screened for their enzyme inhibition potential against AChE and BChE enzymes. Molecular docking studies were carried out to demonstrate putative binding modes. Antioxidant potential of the synthesized compounds was also determined. Enzyme inhibition assay revealed that compounds 02 and 12 showed maximum inhibition against AChE enzyme with percentage inhibition of 91% and 83% respectively, while compounds 12 and 07 showed highest inhibition against BChE with percentage inhibition of 92% and 81% respectively. Molecular docking studies supported the results of enzyme inhibition assay with binding energy values of 8.49 kcal mol 1 against AChE and 8.39 kcal mol 1 against BChE for compound 12. Antioxidant studies also showed good results with percentage scavenging of 96% for both compounds 02 and 19 investigated by DPPH scavenging method. © 2019 Published by Elsevier B.V. 1. Introduction The revolutions in the field of research have explored many secret areas that have the potential to resolve many known prob- lems of the advanced world. Many achievements have been gained in medical sciences, such as cure of many fetal diseases. The importance of developing new drugs, synthesizing new materials having active pharmacophore is a better strategy. Sulfonamide and Schiff base are the two well-known moieties present in active drugs (Fig. 1)[1]. This research work leads to the synthesis of compounds having sulfonamide and Schiff base moieties. Sulfonamides are widely used as antimicrobial [2,3], anticancer [4,5], anti-inflammatory [6] and antiviral agents as well as HIV protease inhibitors [7]. Some sulfonamide derivatives are also well recognized as an antimetab- olite [8]. Sulfonamides have also shown very good cytotoxic effects against breast cancer cells [9]. Sulfonamides were the first effective chemotherapeutic agents which were used competently to check and treat the bacterial infection in human beings [10e13]. Clinically sulfonamides are used to treat several urinary tract infections and gastrointestinal infections [14]. Some sulfonamide derivatives were screened for their antioxidant activity, which showed good results [15]. Sulfonamide being very good phamacophore have also shown very good inhibition against AChE and BChE enzymes [16e18]. Schiff bases also form a group of very important compounds having applications in biological, industrial, pharmaceutical and * Corresponding author. Department of Chemistry, Faculty of Science, University of Gujrat, Gujrat, Pakistan. ** Corresponding author. Chemistry Department, Faculty of Science, King Abdu- laziz University, P. O. Box 80203, Jeddah, 21589, Saudi Arabia. E-mail address: shahzad.murtaza@uog.edu.pk (S. Muratza). Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: http://www.elsevier.com/locate/molstruc https://doi.org/10.1016/j.molstruc.2019.02.056 0022-2860/© 2019 Published by Elsevier B.V. Journal of Molecular Structure 1185 (2019) 8e20