Extraction of Sugars from Black Gram Peels by Reversed-Phase Liquid Chromatography Systems and Identification by TLC and Mass Analysis

A rapid and sensitive method for extraction of sugars from the black gram (Vigna mungo) peels was developed using the solvent mixture of MeOH-dichloromethane-water (MDW) (0.3:4:1v) where the polar MeOH-water phase contained sugars. High-performance liquid chromatography (HPLC) with Evaporative Light Scattering Detector (ELSD) coupled with electrospray ionization mass spectrometric (ESI-MS) analysis in the positive ion mode gave mass data which were employed for the characterization of the analyte sugars. In the TLC analysis using the solvent system of n-butanol-acetone-pyridine-water (10:10:5:5, v/v/v/v), various standard sugars were spotted along with analyte fractions which indicated the presence of sugars, rhamnose, arabinose, xylose, mannose, galactose and glucose in black gram peels. This is the first assay of the sugar profiles of black gram peels, which can be further evaluated for the sugar composition.