Optimization of a green ethanol–water extraction system for Pimenta dioica leaves: Effects on phytochemical content and antioxidant potential

Abstract

The present study investigated the effect of extraction parameters on the phytochemical composition, total phenolic content, and antioxidant activity of Pimenta dioica (L.) Merrill leaf extracts, emphasizing a green and sustainable approach for the efficient utilization of plant biodiversity. Extraction was performed using an ethanol water solvent system at varying solvent ratios (70:30, 80:20 and 90:10), temperatures (60°C, 70°C, and 80°C), and incubation times (60 and 120 min). Preliminary phytochemical screening revealed the presence of major bioactive constituents such as flavonoids, phenols, tannins, saponins, and glycosides in most extracts, while alkaloids appeared only at specific combinations 80:20 at 80°C and 90:10 at 60°C after 60 min, but were detected in nearly all solvent
systems after 120 min. The total phenolic content was highest in extracts obtained at 80:20 solvent ratio, 60°C, and 120 min incubation, indicating the influence of solvent polarity and extraction duration on phenolic recovery. Antioxidant potential evaluated through
reducing power and DPPH radical scavenging assays demonstrated that extracts at 60°C exhibited the highest reducing power, whereas the 70:30 solvent ratio showed superior DPPH radical scavenging activity. Overall, ethanol–water extraction proved effective and environmentally benign for recovering phenolic-rich bioactives from P. dioica leaves. The findings highlight optimized extraction as a green strategy to enhance the recovery of natural antioxidants, supporting the sustainable exploitation of plant biodiversity for
pharmaceutical and nutraceutical applications. The ethanol–water solvent system represents an environmentally benign alternative to conventional organic solvents, being biodegradable, renewable, and safe. Hence, the extraction approach adopted in this study
aligns with green chemistry principles and contributes to sustainable biodiversity utilization