A convenient preparation of glycosyl sulfoxides and its application to the synthesis of Salidroside epimer

Synthesis and bioactivity evaluation of mirror isomer salidroside derivatives as potent antioxidant and anti-inflammatory agents

A series of derivatives of salidroside with mirror isomer glucose and different phenyl moieties were synthesized by Schmidt glycosylation in satisfactory yields, and their antioxidant and anti-inflammatory activities were evaluated by using LPS-induced RAW264.7 cells. One of the synthesized derivatives ʟ-Sal-4, bearing ʟ-glycosyl and -OMe modification at the phenyl ring, exhibited high activity in inhibiting the production of pro-inflammatory cytokines and oxidative stress biomarker MDA as well as in enhancing the activity of SOD enzyme, compared with the natural product and its corresponding ᴅ-enantiomer. Further proteomic analysis suggested that ʟ-Sal-4 exerted its anti-inflammatory activity through metabolic reprogramming. The in vitro activity showed that ʟ-Sal-4 is a potent antioxidant and anti-inflammatory agent. Our finding indicated that the ʟ-glucose-derived salidroside might be a promising lead compound in the development of salidroside derivatives as therapeutic agents.

Urea-hydrogen peroxide prompted the selective and controlled oxidation of thioglycosides into sulfoxides and sulfones

A practical method for the selective and controlled oxidation of thioglycosides to corresponding glycosyl sulfoxides and sulfones is reported using urea-hydrogen peroxide (UHP). A wide range of glycosyl sulfoxides are selectively achieved using 1.5 equiv of UHP at 60 °C while corresponding sulfones are achieved using 2.5 equiv of UHP at 80 °C in acetic acid. Remarkably, oxidation susceptible olefin functional groups were found to be stable during the oxidation of sulfide.