Metabolite of chiral cycloxaprid in solvent and in the raw of Puer tea.

Cycloxaprid (CYC) with a chiral oxabridged cis- structure contains a pair of enantiomers. Enantioselective degradation, transformation and metabolite of CYC was performed in different solvents under light and raw Puer tea processing. The results showed that cycloxaprid enantiomers in acetonitrile and acetone was stable over 17 day, however the transformation of -(-)-cycloxaprid or -(-)-cycloxaprid was founded in methanol. The fastest degradation of cycloxaprid occurred in acetone under light, the metabolites were founded with retention times (T) at 34.83, 15.78 min, which mainly was via the reduce reaction of NO to NO, and rearrange reaction to tetrahydropyran. Degradation pathways were via the cleavage of the oxabridge seven member ring and the whole C ring. However, the degradation pathway under raw Puer tea processing was via the cleavage of whole C ring and the cleavage of oxabridge seven member ring and reducing NO, then it underwent an elimination of nitromethylene and rearrange reaction. This pathway of Puer tea processing was firstly founded.