Optimization of Extraction Conditions for Corilagin and Geraniin from Geranium wilfordii Maxim. Using Response Surface Methodology

초록

Geranium wilfordii Maxim. has long been employed in traditional East Asian medicine owing to its anti-inflammatory and antioxidant properties. Despite its therapeutic potential, previous studies have largely focused on biological activity evaluation, while systematic studies addressing extraction process optimization and standardization for reproducible and industrially applicable use remain scarce. In this study, response surface methodology (RSM) with a Box-Behnken design was applied to establish a process-oriented optimization framework for the extraction of representative ellagitannins from G. wilfordii. The effects of extraction temperature, ethanol concentration, and extraction time on extraction yield, corilagin content, and geraniin content were evaluated. Regression models were constructed from the experimental data, and multi-response optimization was performed using the desirability function. Validation experiments were conducted under the predicted optimal conditions. Extraction temperature and ethanol concentration significantly affected extraction yield and corilagin content, whereas geraniin content was strongly dependent on ethanol concentration. The regression models showed acceptable adequacy with R & sup2; values of 82.96-90.64% and adjusted R & sup2; values of 67.62-82.22%. The predicted optimal conditions were 30 degrees C, 60% ethanol, and 14.67 h, yielding predicted values of 16.46% yield, 11.80 mg/g corilagin, and 60.9 mg/g geraniin. Validation experiments yielded 13.11% yield, 9.97 mg/g corilagin, and 44.05 mg/g geraniin, demonstrating reasonable agreement with the predicted values. These results demonstrate that RSM provides a robust and reproducible framework for extraction process optimization, offering a scientific basis for the standardization and industrial utilization of G. wilfordii extracts as functional ingredients.

키워드