We screened active compounds from natural marine products able to increase PPARalpha/gamma transcriptional activity. Sargaquinoic acid (SQA) and sargahydroquinoic acid (SHQA) from Sargassum yezoense were identified as novel PPARalpha/gamma dual agonists. The binding affinity of SQA with PPARgamma was higher than that of the specific PPARgamma agonist troglitazone, leading to an activation of PPARgamma transcriptional activity. In parallel, treatment of 3T3-L1 cells with SQA and SHQA led to an increase in adipocyte differentiation and increased expression of adipogenic marker genes such as aP2, PPARgamma, resistin, adiponectin, C/EBPalpha and Glut4. Collectively, our data suggest that SQA and SHQA are novel PPARalpha/gamma dual agonists and may be beneficial for reducing insulin resistance through regulation of adipogenesis.