New Derivative and Differential Spectrophotometric Methods for the Determination of Pterostilbene-An Antioxidant

Abstract

Pterostilbene found in blueberries and Pterocarpus marsupium heartwood is structurally similar to resveratrol. It is used for the treatment of cancer, diabetes and fungal infections. Three spectrophotometric methods have been developed for the determination of Pterostilbene. Two first derivative methods and one difference spectrophotometric method were attempted. Two first derivative spectroscopic methods were developed in sodium hydroxide (Method A) and methanol (Method B) and differential spectroscopic method (Method C) was developed using borate buffer and sodium hydroxide. Linearity was observed over the concentration range 0.1-25 and 1-25 μg/ml with linear regression equations y = 0.0043x-0.0003 (R 2 =0.9997) and y=0.0037x - 0.0007 (R 2 =0.9997) for method A and B respectively whereas for method C the linearity was followed over the concentration range 0.1-20 μg/ml with linear regression equation y=0.1124x - 0.0016 (R 2 =0.9999). The three methods were validated and can be applied for the determination of Pterostilbene pharmaceutical formulations. Key words: Derivative spectroscopy, Differential spectroscopy, Pterostilbene, Validation.