Conformational equilibria of 4-thiomaltose and nitrogen analogues of maltose in aqueous solutions.
The 1H and 13C NMR data at neutral pH are presented for methyl 4-thio-beta- and alpha-maltoside (1 and 2) together with methyl 1-thio-alpha-D-glucopyranoside (3) and methyl 4-thio-alpha-D-glucopyranoside (4) as reference compounds. Furthermore, the NMR data at high and low pH are presented for the 4-amino-4-deoxy analogues of methyl alpha-maltoside (5 and 6) and the 5-amino-5-deoxy analogue (8) together with reference compounds methyl 4-amino-4-deoxy-alpha-D-glucopyranoside (7) and 1-deoxynojirimycin (9). The experimental NMR data are assigned by 1- and 2-dimensional spectroscopy at 500 and 600 MHz. The conformational preferences of the maltose analogues 1, 2, 5, 6 and 8 are evaluated by difference NOE experiments, 13C-1H long-range coupling constants, chemical-shift comparison with model compounds and hard-sphere force field calculations for 1 using Monte Carlo simulations. Additionally, the results are compared with extensive experimental NOE data for methyl alpha- and beta-maltoside and the results discussed in light of earlier studies.
Bock
K
K
Department of Chemistry, Carlsberg Laboratory, Copenhagen Valby.
Duus
J O
JO
Refn
S
S
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008320:Maltose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D008969:Molecular Sequence Data; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
C086798:4-thiomaltose; D007202:Indicators and Reagents; D008320:Maltose