Metabolism, transformation and dynamic changes of alkaloids in silkworm during feeding mulberry leaves

Abstract

Metabolism, transformation and dynamic changes of DNJ, 2-O-α-D-Gal-DNJ, fagomine, isofagomine and 4-O-β-d-Glc-fagomine from mulberry leaves in silkworms at different instars were observed. UPLC-Q/TOF-MS and UPLC-TQ/MS methods were adopted for qualitative and quantitative analysis respectively. Three species mulberry leaves were used to feed the silkworm as controls. By analyzing and comparing the content changes of DNJ, fagomine and their derivatives in silkworms and silkworm excrement at different instar, we revealed the dynamic changes, confirmed the enrichment effect of the polyhydroxy alkaloids by silkworm, and inferred the conversion process behind this effect. The experimental results indicated that DNJ and its derivatives turned into some intermediate substances in the metabolic process, and finally they converted back and the content increased. Fagomine and its derivatives interconverted into each other in the process, 4-O-β-d-Glc-fagomine transformed into fagomine, while fagomine transformed into isofagomine.

Graphical Abstract

Keywords:

• Mulberry leaves
• silkworm
• alkaloids
• dynamic changes
• metabolism
• transformation

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Grant numbers 81373889, 81673533]; the Construction Project for Jiangsu Key Laboratory for High Technology Research of TCM Formulae [grant numbers BM2010576; BK2010561]; the Priority Academic Program Development of Jiangsu Higher Education Institutions [grant number ysxk-2014]; 2013’ Program for New Century Excellent Talents by the Ministry of Education [grant number NCET-13-0873], 333 High-level Talents Training Project Funded by Jiangsu Province (2016).