Supercritical CO2 green solvent extraction of Nepeta crispa: Evaluation of process optimization, chemical analysis, and biological activity

Abstract

This research investigates the extraction of compounds from Nepeta crispa (N. crispa), utilizing supercritical carbon dioxide green solvent, for the first time. Using RSM, the study examines the impact of pressure (15-25 MPa), temperature (313-333 K), and co-solvent (0.5- 3.5%) on the extraction yield. The antioxidant activity of the essential oil is assessed through Ferric Reducing Antioxidant Power (FRAP) assay, while its antibacterial properties are evaluated against four bacterial strains. The SCFE method achieved a maximum yield of 1.812% at optimum conditions (P= 25 MPa, T= 313 K and co-solvent= 3.5 %). GC-Mass analysis revealed that the primary constituents of N. crispa essential oil which are 1,8-cineol and 4aα,7α,7aα-nepetalactone in both extraction methods. The antioxidant and antibacterial results of N. crispa showed the superiority of SC-CO2 over hydrodistillation method. These observed antioxidant and antibacterial attributes highlight the plant’s potential suitability for applications within the food and pharmaceutical industries.