Extraction of α-glucosidase inhibitory compounds fromPhaleria macrocarpafruit flesh using solvent, sonication, and subcritical carbon dioxide soxhlet methods

Abstract

The objective of this study was to compare α-glucosidase inhibitory activity of Phaleria macrocarpa extracts using subcritical carbon dioxide (subCO2) soxhlet extraction method with sonication and solvent extraction methods. The extraction was performed by subCO2 soxlet using carbon dioxide and the conventional organic solvent-based sonication using ethanol and water, solvent extraction using methanol, and n-hexane solvents. The yields and α-glucosidase inhibitory activity of the P. macrocarpa extracts were analyzed. The yields using sonication, solvent extraction, and subCO2 soxhlet extraction were approximately 10.2 ± 1.0 to 25.4 ± 0.6% and 0.9 ± 0.1 to 2.0 ± 1.0%. The IC50 value of subCO2 soxhlet, sonication, and solvent extraction methods were 4.35, 7.34, and 1.9 µg/mL, respectively. The α-glucosidase inhibitory activity of P. macrocarpa extract using subCO2 soxhlet method was higher than the conventional sonication method and lower than the solvent extraction method. Overall, subCO2 soxhlet extraction of P. macrocarpa represents a promising method to produce organic solvent free and highly α-glucosidase inhibitory compounds containing extracts. Practical applications This study compared the conventional and nonconventional extraction methods for separating bioactive compounds from P. macrocarpa. Plant extracts contain a large variety of bioactive compounds with many other constituents including pharmaceuticals that require separations, purifications, and fractionations for further processing. Pharmaceutical industries are always looking for green processing methods obtaining green products. Nonconventional methods are of great interest owing to their efficiency such as fast, organic-residues-free, low temperature processing, and cost-effective compare to any conventional method. Moreover, nonconventional methods are technologically advanced and claimed to be green with innumerable applications. Bioactive compounds of P. macrocarpa extracted by nonconventional methods may retain the natural quality that is of organic residues free and can be further exploited for the pharmaceutical, cosmetic, functional foods, and neutraceuticals industries. The environmental issues and health concerns of society are also demanding the green technology in our daily life.