Characterization of Microbial Degradation Products of Steviol Glycosides

Steviol glycosides were subjected to bacteria present in a soil sample collected from a Stevia plantation in Paraguay. During the incubation experiments, next to the aglycon steviol, steviol degradation products were also formed. X-ray analysis and NMR methods in combination with chemical synthesis and GIAO NMR calculations were used to fully characterize the structure of these compounds as a tricyclic ketone and the corresponding reduced form. They were nicknamed monicanone and monicanol. The latter has the (S)-configuration at the alcohol site.

Automated summary

The Steviol glycosides were exposed to bacteria from soil samples taken from a Stevia plantation in Paraguay, resulting in the formation of degradation products alongside the aglycon steviol. X-ray analysis, NMR methods, chemical synthesis, and GIAO NMR calculations were used to fully characterize the structure of these compounds, identified as a tricyclic ketone and its reduced form, named monicanone and monicanol respectively. The latter has an (S)-configuration at the alcohol site.