92189-30-5

Upstream product

• 100-52-7 benzaldehyde 
• 156-38-7 4-hydroxyphenylacetate 
• 6554-98-9 trans-4-Hydroxystilbene 
• 868522-85-4 O-4-stilbenyl N,N-dimethylthiocarbamate 

Relevant academic research and scientific papers

Extraordinary radical scavengers: 4-mercaptostilbenes

In the past decade, there was a great deal of interest and excitement in developing more active antioxidants and cancer chemoprevention agents than resveratrol, a naturally occurring stilbene. In this work, eight resveratrol-directed 4-mercaptostilbenes were constructed based on the inspiration that thiophenol should be a stronger radical scavenger than phenol, and their reaction rates with galvinoxyl (GO.) and 2,2-diphenyl-1-picrylhydrazyl (DPPH.) radicals in methanol and ethyl acetate were measured by using stopped-flow UV/Vis spectroscopy at 25 °C. Kinetic analysis demonstrates that 4-mercaptostilbenes are extraordinary radical scavengers, and the substitution of the 4-SH group for the 4-OH group in the stilbene scaffold is an important strategy to improve the radical-scavenging activity of resveratrol. Surprisingly, in methanol, some of the 4-mercaptostilbenes are 104-times more active than resveratrol, dozens of times to hundreds of times more effective than known antioxidants (α-tocopherol, ascorbic acid, quercetin, and trolox). The detailed radical-scavenging mechanisms were discussed based on acidified-kinetic analysis. Addition of acetic acid remarkably reduced the GO. and DPPH. radical-scavenging rates of the 4-mercaptostilbenes in methanol, a solvent that supports ionization, suggesting that the reactions proceed mainly through a sequential proton loss electron transfer mechanism. In contrast, an interesting acid-promoted kinetics was observed for the reactions of the 4-mercaptostilbenes with DPPH. in ethyl acetate, a solvent that weakly supports ionization. The increased ratio in rates is closely correlated with the electron-rich environment in the molecules, suggesting that the acceleration could benefit from the contribution of the electron transfer from the 4-mercaptostilbenes and DPPH.. However, the addition of acetic acid had no influence on the GO.-scavenging rates of the 4-mercaptostilbenes in ethyl acetate, due to the occurrence of the direct hydrogen atom transfer. Our results show that the radical-scavenging activity and mechanisms of 4-mercaptostilbenes depends significantly on the molecular structure and acidity, the nature of the attacking radical, and the ionizing capacity of the solvent. Copyright

The conversion of stilbenols to stilbenethiols via N,N- dimethylthiocarbamates

A series of O-stilbenyl N,N-dimethylthiocarbamates has been prepared by the reaction of N,N-dimethylthiocarbamoyl chloride with stilbenols in the presence of DABCO and DMF. The thermal rearrangement of O-stilbenyl N,N- dimethylthiocarbamates into S-stilbe