Table I.
Observed (Obs.) and calculated (Calc.) three-bond proton–proton vicinal couplings (JH,H, Hz) for the five α-d-monosaccharides in water
| Hexosamine | Coupling | Obs. | Calc. |
|---|---|---|---|
| GlcNAc | J1,2 | 3.5 | 3.2 |
| GlcNAc | J2,3 | 10.7 | 10.1 |
| GlcNAc | J3,4 | 9.9 | 9.9 |
| GlcNAc | J4,5 | 9.3 | 10.0 |
| GlcNAc | JHN,H2 | 8.8 | 9.7 |
| GlcNAc | J5,6proR | 5.2a | 4.5 |
| GlcNAc | J5,6proS | 2.3a | 3.2 |
| GlcNS | J1,2 | 3.5 | 2.6 |
| GlcNS | J2,3 | 10.4 | 10.2 |
| GlcNS | J3,4 | 9.0 | 9.9 |
| GlcNS | J4,5 | 10.2 | 10.0 |
| GlcNS6S | J1,2 | 3.5 | 2.6 |
| GlcNS6S | J2,3 | 10.4 | 8.8 |
| GlcNS6S | J3,4 | 9.1 | 9.8 |
| GlcNS6S | J4,5 | 10.1 | 9.9 |
| GlcNS6S3S | J1,2 | 3.3 | 2.7 |
| GlcNS6S3S | J2,3 | 10.7 | 10.2 |
| GlcNS6S3S | J3,4 | 8.9 | 8.3 |
| GlcNS6S3S | J4,5 | 10.1 | 10.0 |
| GlcNS3S | J1,2 | 3.3 | 2.7 |
| GlcNS3S | J2,3 | 10.7 | 10.2 |
| GlcNS3S | J3,4 | 8.8 | 9.9 |
| GlcNS3S | J4,5 | 10.1 | 8.5 |
The Karplus equations of Hricovini and Bizik, Altona and Haasnoot (1980) and Mobli and Almond (2007) were used for pyranose ring, hydroxymethyl and acetamido vicinal couplings, respectively. Experimental errors were estimated to be ±0.2 Hz and standard deviations of calculated ring vicinal couplings were estimated to be at most 0.01 Hz. (except GlcNAc J5,6proR which was ±0.1 Hz).
aData from a previous NMR study (Blundell et al. 2009).