Saponins from Panax bipinnatifidus Seem.: New strategy of extraction, isolation, and evaluation of tyrosinase inhibitory activity based on mathematical calculations

A hyphenated accelerated solvent extraction (ASE) technique coupled with centrifugal partition chromatography (CPC), ultra high performance liquid chromatography (UPLC), and mass spectrometry (MS) was established. The CPC fractions were prepared using the hyphenated technique. Subsequently, tyrosinase inhibitory activities of the CPC fractions were experimentally evaluated, and the activities of individual components were calculated theoretically. This new approach was applied to saponin fractions obtained from 10.0 g of raw Panax bipinnatifidus Seem. via a biphasic solvent system of ethyl acetate/n-butanol/methanol/water (2:3:2:5, v/v/v/v). The CPC fractions monitoring was performed using an online UPLC/PDA system at 5-min intervals. The tyrosinase inhibitory activities of all fractions were analysed using the fluorescence method. Mathematical calculations indicated that the inhibition rates of the ginsenosides Rh1, Rh2, Rg1, Rg2, and chikusetsusaponin L5 were all above 50.00%, showing potential for further development. The results were confirmed by comparison with authentic standards.