Synthesis, crystal structure, thermal analysis and biological activities of sodium 5-carboxy-2,3-dihydroxybenzenesulfonate

ABSTRACT

Through the sulfonation of protocatechuic acid, sodium 5-carboxy-2,3-dihydroxybenzenesulfonate (SPA) was synthesized. The structure of the sulfonated derivative was confirmed by FT-IR, MS, ¹H NMR, ¹³C NMR, single crystal X-ray diffraction, and thermogravimetric analysis. The antioxidative activities of the derivative SPA were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging method and reducing power determination, showing that SPA had strong antioxidative effects. Meanwhile DPPH scavenging progress by SPA was analyzed from dynamics experiments. Isothermal titration calorimetry (ITC) and circular dichroism (CD) were applied to investigate the interaction between the derivative SPA and human serum albumin (HSA).

KEYWORDS:

• Antioxidative activity
• circular dichroism
• crystal structure
• isothermal titration calorimetry
• protocatechuic acid
• thermogravimetric analysis

Acknowledgments

This work was financially supported by the Natural Science Foundation of China (21362001), and Natural Science Foundation of Guangxi Province (2013GXNSFDA019005).