Beta-D-glucosyl and alpha-D-galactosyl Yariv reagents: syntheses from p-nitrophenyl-D-glycosides by transfer reduction using ammonium formate.
Yariv beta-D-glucosyl (4a) and Yariv alpha-d-galactosyl (4b) reagents are multivalent phenylglycosides. The beta-D-glucosyl reagent is considered diagnostic for arabinogalactan proteins (AGPs) to which it can reversibly bind, stain, and precipitate. The alpha-D-galactosyl reagent does not bind AGPs and is used as a control. In a new strategy, we accomplished the large scale synthesis of the Yariv reagents in one continuous step by a transfer reduction method and without a need for any specialized apparatus. As the starting material, p-nitrophenyl-D-glycosides (1) were reduced to p-aminophenyl-D-glycosides (2) using ammonium formate as the hydrogen donor. The excess formate was converted to formic acid and ammonia, which then were removed from the reaction by simple distillation. Without isolation, p-aminophenyl-D-glycosides were diazotized (3) and coupled to phloroglucinol to give the Yariv reagents in approximately 40% yield. AGPs are a major component of gum arabic, an emulsifying agent widely used in the food and pharmaceutical industries. Increasing interest in AGPs prompted the development of a relatively easy and inexpensive method for the synthesis of these reagents.
Basile
Dominick V
DV
Departments of Biological Sciences and Chemistry, Lehman College of the City University of New York, Bronx, NY 10468, USA. basile@lehman.cuny.edy
Ganjian
Iraj
I
D005561:Formates / Q000737:chemistry*; D005960:Glucosides / Q000138:chemical synthesis*; D006027:Glycosides / Q000737:chemistry; D009596:Nitrophenols / Q000737:chemistry; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
D005561:Formates; D005960:Glucosides; D006027:Glycosides; D009596:Nitrophenols; C104977:Yariv reagent; C030544:formic acid; D010696:Phloroglucinol