Table 1.
One-pot three-enzyme (OP3E) synthesis of sialosides containing Neu5,7diN3 or Neu5,7,9triN3 (31–56) from Man2,4diN3 (9) or Man2,4,6triN3 (11) and chemical conversion of the azido groups to N-acetyl moieties to form sialosides containing desired Neu5Ac7NAc or Neu5Ac7,9diNAc (57–82). The Cbz group in the resulting sialosides was removed from the NAc-sialosides in quantitative yields to produce sialosides containing a propylamine aglycone for glycan microarray studies. R’ differs from R by replacing the propyl NHCbz aglycon in R with the propylamine (ProNH2) in R’.
| ||||
|---|---|---|---|---|
Acceptor (ROH)
|
 31–56 (64–100%) |
 57–82 (64–89%) |
||
| α2–3-sialosidea Neu5,7diN3/ Neu5,7,9triN3α3OR |
α2–6-sialosideb Neu5,7diN3/ Neu5,7,9triN3α6OR |
α2–3-sialoside Neu5Ac7NAc/Neu5Ac7,9diNAcα3OR |
α2–6-sialoside Neu5Ac7NAc/Neu5Ac7,9diNAcα6OR |
|
 LacβProNHCbz (24) |
X=OH, 31 (90%) X=N3, 32 (92%) |
X=OH, 33 (quant.) X=N3, 34 (quant.) |
Y=OH, 57 (68%) Y=NHAc, 58 (80%) |
Y=OH, 59 (78%) Y=NHAc, 60 (80%) |
 LacNAcβProNHCbz (25) |
X=OH, 35 (70%) X=N3, 36 (66%) |
X=OH, 37 (72%) X=N3, 38 (65%) |
Y=OH, 61 (67%) Y=NHAc, 62 (67%) |
Y=OH, 63 (77%) Y=NHAc, 64 (85%) |
 Galβ3GalNAcβProNHCbz (26) |
X=OH, 39 (99%) X=N3, 40 (67%) |
X=OH, 41 (Quant.) X=N3, 42 (69%) |
Y=OH, 65 (64%) Y=NHAc, 66 (65%) |
Y=OH, 67 (67%) Y=NHAc, 68 (70%) |
 Galβ3GalNAcαProNHCbz (27) |
X=OH, 43 (95%) X=N3, 44 (65%) |
X=OH, 45 (68%) X=N3, 46 (79%) |
Y=OH, 69 (77%) Y=NHAc, 70 (65%) |
Y=OH, 71 (77%) Y=NHAc, 72 (72%) |
 Galβ3GlcNAcβProNHCbz (28) |
X=OH, 47 (87%) X=N3, 48 (64%) |
X=OH, 49 (quant.) X=N3, 50 (91%) |
Y=OH, 73 (73%) Y=NHAc, 74 (66%) |
Y=OH, 75 (75%) Y=NHAc, 76 (70%) |
 Galβ3GlcNAcαProNHCbz (29) |
X=OH, 51 (93%) X=N3, 52 (87%) |
X=OH, 53 (quant.) X=N3, 54 (96%) |
Y=OH, 77 (89%) Y=NHAc, 78 (69%) |
Y=OH, 79 (72%) Y=NHAc, 80 (68%) |
 GalNAcαProNHCbz (30) |
X=OH, 55 (65%) X=N3, 56 (65%) |
Y=OH, 81 (84%) Y=NHAc, 82 (85%) |
||
a
PmST1 was used as the α2–3sialyltransferase;
b
Pd2,6ST was used as the α2–6sialyltransferase.