An experimental design approach for the optimization of scopoletin extraction from Morinda citrifolia L. using accelerated solvent extraction

Scopoletin is regarded as a major constituent of noni (Morinda citrifolia L), which contributes to the antioxidative, anti-inflammatory, immunomodulatory, and hepatoprotective properties in noni. It is also suggested as a marker for identification and quality control of noni and its derivative products. With the increasing interest in noni due to its health benefits and therapeutic effects, it is important to establish a reliable extraction and analysis method to determine scopoletin content in noni samples. The present study proposes the use of accelerated solvent extraction (ASE) to extract scopoletin from noni, followed by detection using HPLC-DAD for rapid identification and quantification of scopoletin. The optimum operating conditions of ASE were investigated using response surface methodology (RSM), using a three factors central composite design. It was found that the optimum scopoletin yield was achieved by performing the extraction at an elevated temperature of 60 °C for 12 min, using ethanol as extraction solvent with solid to solvent ratio of 1:30 (w/v). The analytical method validation was carried out under optimum conditions. The results indicate that the proposed ASE-HPLC-DAD method was adequately sensitive for the quantification of scopoletin in extracts with limit of detection of 0.17 μg/g. The presented method also exhibits excellent linearity from 0.54 to 120.10 μg/g with R2 0.9995, high precision with RSD lower than 2% for intra-day and inter-day replication, and good recovery (99.88%). The established method was also successfully applied for scopoletin determination in noni product samples. The developed method provides a rapid and reliable method for the identification and quantification of scopoletin in noni samples that is suitable for routine procedures.