Simultaneously Probing and Identification of Radical-scavenging Compounds in Biological Materials with Paralleling Detection System

摘要

In search for new natural antioxidants in biological matrixes, bioassay-guided fractionation is usually used. However, the procedure needs large amount of starting materials and is inefficient both in time and labors. Beside, during purification process the antioxidants are easy to decompose and loss activities. This obviously will retard the advance of natural antioxidant finding. Numbers of groups developed methods for separating and then identified the components immediately isolated from antioxidation active materials by LC-MS (1), which allowed us to elucidate or identify the structure of the LC eluted components but this still cannot tell us which components possess antioxidative activities. For this reason, a method combining separation and activity evaluation would be favorable for such investigation. Recently, Koleva et al. published a new rapid on-line method for screening complex mixtures for radical scavenging components using a methanolic solution of the DPPH.. stable free radical (2). The advantage of this method is that it is no longer necessary to purify each component for off-line assays and the radical scavenging activity of each single substance can be measured immediately. However, this method cannot provide the structure information about the scavenging-active constituents.