Optimization of ionic liquid-based microwave assisted extraction to obtain trans-resveratrol from Gnetum gnemon L. Seeds

Introduction: Gnetum gnemon L. (Melinjo) is popular in Indonesia as a source of nutrition. Its seeds contain trans-resveratrol, 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 trans-resveratrol from Melinjo seeds. MAE method with ionic liquid has also been applied to extract trans-resveratrol from the different plant with a high extraction yield value. Methods: The Box-Behnken design on four factors with response surface methodology were used to optimize extraction conditions for trans-resveratrol content from Melinjo seeds. For further, the various salt was applied to separate of the trans-resveratrol form ionic liquid and facilitate for extraction back using an organic solvent. Results: 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 trans-resveratrol value was 1.34 mg/g. Moreover, the salt Na2CO3 0.01 mol/L with ethyl acetate were useful to the extraction back of trans-resveratrol from [Bmim]Br solution. Conclusion: This IL-MAE method was suitable to apply as an alternative technique to extract the active compound from the plant.