Rapid Identification of Glycosides and Aglycones in Pericarp of Sapindus mukorossi Gaertn. Using UHPLC-LTQ Orbitrap MS

Sapindus mukorossi Gaertn. is a Chinese medicinal herb, which has been used for thousands of years in China. The extract of sapindus pericarp has strong surfactivity and biological activities, such as anti-inflammatory, antimicrobial, antitumor, spermicidal, hepatoprotective and fungicidal activities. The major bioactive compounds of Sapindus mukorossi are saponins and sesquiterpene glysides, which are natural non-ionic suractants. The development of liquid chromatography coupled with mass spectrometry technology (LC/MS) provides a simple and rapid method for complex traditional Chinese medicine. LC/MS technology can not only reach the point of high separating capacity of chromatography but also be provided with high selectivity, sensitivity, relative molecular mass and structure information of mass spectrum. The application of this technique generally involves LC/MS data acquisition, data processing and structure identification．In this study, a method of ultra high performance liquid chromatography-linearion trap/orbitrap high resolution mass spectrometry (UHPLC-LTQ Orbitrap MS) and a variety of data acquisition and mining strategy were provided for the pericarp of Sapindus mukorossi. The mass spectrum characterization of two kinds of saponins standards were optimized for rapid screening and qualitative identification of glycosides; explored PIL （parent ion list）-MS², PIL-MS³ and HCD （high energy collision dissociation） techniques for the identification of nucleus structurally similar compounds. Finally, high-throughput screening of new glycosides compounds was performed by using the intelligent In silico strategy (FISH and MS Tree Match in Mass Frontier software), and those new chemical compounds were validated by HCD fragmentation model. Total of 67 glycosides were identified in the pericarp of Sapindus mukorossi, and 38 compounds were quickly screened and identified, 8 compounds with similar nucleolus structures were distinguished, 11 new components were inferred in the plant. This method can provide reference data for the study of Sapindus mukorossi quality control and pharmacodynamics development, and also can provide valuable reference for rapid qualitative analysis of complex traditional Chinese medicine.