Comparison of bioactive compounds and their antioxidant potentials of three varieties of Labisia pumila Benth. extracts obtained from different extraction methods. Ehsan Karimi1*, Hawa Z. E. Jaafar2, Pooyan MehrabanJoubani3

Extraction methods are very important processes for separation of bioactive compounds of medicinal plants before analyses. Phenolic and flavonoid compounds include a broad variety of structures and functionalities that are required for the production of foods and food additives and there are different methods for the their extraction. In this study, total phenolic and flavonoid contents of leaf extracts from three varieties of Labisia pumila Benth (variety alata, pumila, and lanceolata) were investigated by microwave assisted extraction (MAE) and reflux extraction methods. Furthermore, DPPH radical-scavenging and ferric-reducing antioxidant power (FRAP) assays were applied to test the antioxidant activities. Results revealed that total phenolic (3.14, 3.03, 2.94 mg GAE g-1 DW) and flavonoid contents (2.08, 2.1, 1.85 mg Rutin g-1 DW) in the leaf extracts of Labisia pumila varieties alata, pumila, and lanceolata by MAE method were significantly higher than reflux extraction method, which was possibly responsible for the higher antioxidant activities in all three varieties of L. pumila Benth. These findings further illustrate that MAE has a bright prospect for extracting active ingredients from plant materials.