Optimization of Ionic Liquid-Based Microwave Assisted Extraction to Obtain Trans-resveratrol from Gnetum gnemon L. Seeds

Abstract

<p style="text-align: justify;"><strong>Introduction:</strong> <em>Gnetum gnemon</em> L. (Melinjo) is popular in Indonesia as a source of nutrition. Its seeds contain <em>trans-resveratrol</em>, which has been shown to have multiple pharmacological activities. The application of ionic liquid [Bmim]Br as a selected solvent in the microwave assisted extraction (MAE) method was developed for extraction of <em>trans-resveratrol</em> from Melinjo seeds. MAE method with ionic liquid has also been applied to extract <em>trans-resveratrol</em> from the different plant with a high extraction yield value. <strong>Methods:</strong> The Box-Behnken design on four factors with response surface methodology were used to optimize extraction conditions for transresveratrol content from Melinjo seeds. For further, the various salt was applied to separate of the <em>trans-resveratrol</em> form ionic liquid and facilitate for extraction back using an organic solvent. <strong>Results:</strong> The optimum process for the ionic liquid-based microwave assisted extraction was below: [Bmim]Br concentration 2.5 mol/L; liquid-melinjo seeds powder ratio 15 mL/g; microwave power 10%; and extraction time 10 min. Under optimized conditions, the <em>trans-resveratrol</em> value was 1.34 mg/g. Moreover, the salt Na2CO3 0.01 mol/L with ethyl acetate were useful to the extraction back of <em>trans-resveratrol</em> from [Bmim]Br solution. <strong>Conclusion:</strong> This IL-MAE method was suitable to apply as an alternative technique to extract the active compound from the plant. <p style="text-align: justify;"><strong>Key words:</strong> Ionic liquid, <em>Gnetum gnemon</em>, Melinjo, Microwave assisted extraction, <em>Trans-resveratrol</em>, Response surface methodology.