title: Synthesis of oligomers of β-l-arabinofuranosides of (4R)-4-hydroxy-l-proline relevant to the mugwort pollen allergen, Art v 1.
abstract: An efficient, convergent solution phase synthesis of monomer, dimer, trimer and tetramer of the β-l-arabinofuranosylated hydroxyproline (β-l-Araf-Hyp) glycocluster is described. This motif constitutes the carbohydrate-specific epitope of Art v 1, the major allergen of mugwort pollen. While a single monomeric unit was proposed at the outset, poor yields for the seemingly trivial steps of end-capping to replace protecting groups with N-terminal acetamides and C-terminal methyl amides led to the introduction of N-terminal, central and C-terminal β-l-Araf-Hyp building blocks. Dimer 2 was obtained in 60% yield by coupling of two monomers, followed by hydrogenolysis of benzyl ether protecting groups. Trimer 3 was obtained in 35% yield via a [2 + 1] coupling and tetramer 4 in 15% yield via a [2 + 2] fragment condensation. Circular dichroism spectra show that monomer 1 displays no organized structure, whereas compounds 2-4 show a strong negative band at 200 nm and a weak positive band at ∼220 mn, as is characteristic of the polyproline II helix.
authors: Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors: Ning
authors: N
authors: Xie
authors: Carol M
authors: CM
authors: Taylor
mesh_terms: D000485:Allergens / Q000737:chemistry*; D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000737:chemistry*; D019306:Artemisia / Q000737:chemistry*; D002942:Circular Dichroism; D019281:Dimerization; D006023:Glycoproteins / Q000737:chemistry*; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D006909:Hydroxyproline / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010940:Plant Proteins / Q000737:chemistry*; D011058:Pollen / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C102724:Art v 1 protein, mugwort; D006023:Glycoproteins; D006027:Glycosides; D010940:Plant Proteins; C555099:beta-(1,4)-L-arabinosyl-(2S,4R)-4-hydroxyproline; D011392:Proline; D006909:Hydroxyproline