Résumé
The purpose of this article is to study the degradation of chemical compositions after the silkworm excrement being expelled from the silkworm, and to determine its main metabolic compositions and their changing relationships. This research is based on UPLC-Q-TOF-MS technology. Based on the systematic analysis of the main chemical compositions contained in silkworm excrement, the principal compositions analysis(PCA) and partial least squares discriminant analysis(OPLS-DA) on commercial silkworm excrement and fresh silkworm excrement were analyzed for differences. The S-plot chart of OPLS-DA was used to select and identify the chemical compositions that contributed significantly to the difference. At the same time, the relative peak areas of the different compositions were extracted by Masslynx to obtain the relative content of different compositions in fresh silkworm excrement. The results showed that there was a significant difference in the chemical compositions between fresh silkworm excrement and commercial silkworm excrement. The difference compositions were mainly flavonoid glycosides and Diels-Alder type composition, and two types of compounds are degradated during the storage of silkworm sand. In this study, the chemical compositions of fresh silkworm excrement were systematically identified and analyzed for the first time by mass spectrometry, and it was found that some chemical compositions of silkworm excrement were degradated with time during storage.