258286-51-0Relevant articles and documents
Directing effect by remote electron-withdrawing protecting groups at O-3 or O-4 position of donors in glucosylations and galactosylations
Baek, Ju Yuel,Kwon, Hea-Won,Myung, Se Jin,Park, Jung Jun,Kim, Mi Young,Rathwell, Dominea C.K.,Jeon, Heung Bae,Seeberger, Peter H.,Kim, Kwan Soo
, p. 5315 - 5320 (2015/07/15)
Glucosylations and galactosylations of various acceptors with donors possessing an electron-withdrawing benzylsulfonyl, benzoyl, or acetyl group at the O-3 or O-4 position were performed. A β-directing effect by the benzylsulfonyl group at O-3 of the glucosyl donors and by the benzylsulfonyl and acyl groups at O-4 of the glucosyl donors was observed. In contrast, acyl groups at O-3 of the glucosyl donors and acyl groups at O-3 and O-4 of the galactosyl donors exhibited an α-directing effect. The α-directing effect is partly considered to remote participation of the acyl groups, whereas the β-directing effect is somewhat attributed to the SN2-like reaction of the acceptor with the glycosyl triflate or the contact ion pair, which is stabilized by remote electron-withdrawing groups. Further evidence for the stability of the α-glycosyl triflates was determined by a low-temperature NMR study.
The synthesis of deoxy-α-Gal epitope derivatives for the evaluation of an anti-α-Gal antibody binding
Janczuk, Adam J.,Zhang, Wei,Andreana, Peter R.,Warrick, Joshua,Wang, Peng G.
, p. 1247 - 1259 (2007/10/03)
α-Gal epitopes (also termed as α-Gal) are carbohydrate structures bearing the α-D-Gal-(1→3)-β-D-Gal terminus 1 and are known to be the antigen responsible for antibody-mediated hyperacute rejection in xenotransplantation. Terminal 2-, 3-, 4-, and 6-deoxy-Gal derivatives of α-Gal were synthesized. Inhibition ELISA using mouse laminin was established to determine the binding affinity of the synthesized α-Gal derivatives. 4-Deoxy-α-Gal derivative 7 showed a significant reduction in antibody recognition. The IC50 value was 15-fold poorer than the standard α-Gal epitopes α-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Glc-NHAc (39) and α-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Glc-OBn (40). A similar observation was seen with 2-deoxy-α-Gal derivative 5, whose IC50 value was nearly tenfold higher than the standards. Interestingly, substitution at the terminal 3-position resulted in only a fourfold decrease in antibody recognition, suggesting a possible point of future derivation. Finally, 6-deoxy-α-Gal derivative 8 exhibited similar antibody recognition to both α-Gal epitope 39 and α-Gal epitope 40. This strongly suggests that derivatization at the 6-position can be accomplished without loss of antibody recognition. These findings can be utilized for the future design of other α-Gal derivatives.
