Synthesis, characterization, and pharmacological evaluation of the proton transfer salts of 2-aminobenzothiazole derivatives with 5-sulfosalicylic acid and their Cu(II) complexes

Abstract

Two proton transfer compounds, formed between 2-aminobenzothiazole derivatives (2-aminobenzothiazole (abt) and 2-amino-6-ethoxybenzothiazole (EtOabt)) and 5-sulfosalicylic acid dihydrate (H₃ssa) as parent compounds, (Habt)⁺(H₂ssa)⁻ (1) and (HEtOabt)⁺(H₂ssa)⁻ (2) and their Cu(II) complexes (3 and 4, respectively) have been prepared and characterized using spectroscopic techniques. The single crystal X-ray diffraction method has been also applied to 3 and 4. Although 3 has a distorted octahedral form, 4 exhibits a distorted square pyramidal geometry. All compounds, including saline and diclofenac sodium as standards, have been evaluated pharmacologically for their anti-inflammatory and analgesic activities in rats and mice. Parent compounds (abt, EtOabt, and H₃ssa) 3 and 4 show significant anti-inflammatory and analgesic activities as compared with control compounds.

Graphical Abstract

Keywords:

• 2-Aminobenzothiazole derivatives
• 5-sulfosalicylic acid
• proton transfer salt
• anti-inflammatory activity
• analgesic activity

Acknowledgments

The authors would like to thank Aksaray University, Science and Technology Application and Research Center, Aksaray, Turkey, for having been allowed to use the X-ray facility.

Additional information

Funding

The authors acknowledge the support provided by Dumlupınar University Research Fund (Grant No. 2017/09).