Application of Response Surface Methodology for the Optimization of the Extraction of Triterpenoid Saponins from Azadirachta excelsa Leaves

Abstract

Azadirachta excelsa originates from the Meliaceae family and is often subjected to bioactivity studies due to the presence of various types of compounds such as phenolics, flavonoids and terpenes. Triterpenoid saponins are diverse groups under terpenoids and are secondary metabolites produced by plants for carrying out antagonistic and mutualistic interactions. These compounds are extensively investigated for bioactivities such as anticancer, antimicrobial and pesticidal properties due to their wide range of action mechanism. This study aimed to optimize A. excelsa leaves extraction process using response surface methodology (RSM) for obtaining extract with high extract yield and triterpenoid saponins content. The independent variables selected for the extraction process included temperature, ethanol-to-chloroform ratio, time and sample-to-solvent ratio. The individual and interactional effects of extraction parameters on the yield of extract and triterpenoid saponins content were evaluated using Central composite design (CCD) of RSM. The responses were predicted using second order polynomial model. One-way analysis of variance (ANOVA) revealed correlation coefficients (R2) of developed model for yield of extract and triterpenoid saponins contents were 0.9792 and 0.9509. High F-statistics value and lower p-value (