Optimization of sulfation of okra fruit gum for improved rheological and pharmacological properties

In the present investigation, sulfated derivatives of Okra fruit gum (OFG) with the degree of substitution (DS) ranging from 0.39 to 1.13 were synthesized using chlorosulfonic acid/pyridine (CSA/Py) reagents under the umbrella of Box-Behnken Design (BBD) of Response Surface Methodology (RSM) to optimize the reaction conditions. The extracted gum was characterized for particle size, zeta-potential, surface morphology, architectural arrangement, mechanical and rheological chattels, pharmacological properties etc. The optimal reaction conditions of sOFG (sulfated okra fruit gum) were included ratio of CSA/Py, 0.28; reaction time, 3.05 h and reaction temperature, 58.74 °C. A high DS of 1.004 was procured at optimized conditions that was analogous to the predicted value. The sOFG was investigated to be advanced over the immensely used polysaccharide sodium alginate in mechanical and rheological attributes. Also, pharmacological properties including anticoagulant and antimicrobial property of sOFG were superior as compared to OFG. In conclusion, sulfation of OFG under the shed of BBD offered a superior DS that could be further explored for wide usage as pharmaceutical excipient for designing health care products.