Cipadesin limonoids are a group of oxygenated tetracyclic triterpenoids with various biological effect spresent in Rutaceae and Maliaceae families. Up to now, nuclear magnetic resonance (NMR) spectroscopy plays an important role in the analysis of cipadesin limonoids. However, many trace cipadesin limonoids in plant cannot be analysed by NMR method.

In order to establish a reliable, fast and low-cost analysis method, researchers in Prof. ZHANG Guolin  lab at the Chengdu Institute of Biology, Chinese Academy of Sciences investigated the structure characteristic of six cipadesin limonoids using electrospray tandem mass spectrometry (ESI-MS/MS) method.

Prof. ZHANG and his colleagues revealed firstly fragmentation rules of cipadesin limonoids. And the corresponding information can be used for the rapid analysis of cipadesin limonoids, including isomers with similar structure, in complex mixtures from plant extract. In addition, they found the rare radical production formed by anti-even-electron rule, which is of scientific interest.

The method is a rapid and new analysis method of limonoids and is especially valuable for reliable and rapid identification of these compounds or their metabolites in complex mixtures.

This research entitled "Analysis of cipadesin limonoids from Cipadessa cinerascens using electrospray ionization quadrupole time-of-flight tandem mass spectrometry and quantum chemical calculations" was published in Rapid Commun. Mass Spectrom. on March 15, 2012. (http://onlinelibrary.wiley.com/doi/10.1002/rcm.6126/full)