Nature-effect transformation mechanism of mulberry leaves and silkworm droppings based on chemical composition analysis

Abstract

Starting with the relationship between mulberry leaves and silkworm droppings as food and metabolites, this study systematically compared the chemical components, screened out differential components, and quantitatively analyzed the main differential components based on ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) and UPLC-Q-TRAP-MS combined with principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA). Moreover, the in vitro enzymatic transformation of the representative differential components was studied. The results showed that(1) 95 components were identified from mulberry leaves and silkworm droppings, among which 27 components only exist in mulberry leaves and 8 components in silkworm droppings. The main differential components were flavonoid glycosides and chlorogenic acids.(2) Nineteen components with significant difference were quantitatively analyzed, and the components with significant differences and high content were neochlorogenic acid, chlorogenic acid, and rutin.(3) The crude protease in the mid-gut of silkworm significantly metabolized neochlorogenic acid and chlorogenic acid, which may be an important reason for the efficacy change in mulberry leaves and silkworm droppings. This study lays a scientific foundation for the development, utilization, and quality control of mulberry leaves and silkworm droppings. It provides references for clarifying the possible material basis and mechanism of the pungent-cool and dispersing nature of mulberry leaves transforming into the pungent-warm and dampness-resolving nature of silkworm droppings, and offers a new idea for the study of nature-effect transformation mechanism of traditional Chinese medicine.