Green Extraction of Antioxidant Compounds from Adiantum capillus-veneris L. and Optimization According to Response Surface Methodology

In the wake of growing concerns regarding the safety of our ecosystems, environmentally sustainable protocols for natural antioxidant extraction from plants are highly desirable. The current article is the outcome of the realization of this compelling need. Adiantum capillus-veneris L. is a widely found fern species known for its several ethnomedicinal uses. It is rich in phytochemicals such as phenolics of different types. In the current study, isopropanol-propylene glycol binary solvent was used as an extractant for bioactive compounds from this plant. The input factors used for optimization were time, temperature, solvent-to-solid ratio (SSR), selected responses were total phenolic content (TPC), total flavonoid content (TFC), and radical scavenging activity (RSA). The optimum conditions found by numerical optimization were SSR ۳۰ mL/g, time ۲.۶۲ h, and temperature ۶۰ °C with predicted TPC, TFC, and RSA as ۱۶.۱۴ mg gallic acid equivalents/g dry weight (DW), ۵۷.۶۴ mg rutin equivalents/g DW, and ۹۴.۶۳ %, respectively. The validation study strongly supported the suggested model with only a small % error. Based on these findings, a procedure may be developed for the safe and sustainable extraction of antioxidants from A. capillus-veneris for industrial application using isopropanol-propylene glycol binary solvent.