TY - JOUR
T1 - Structural characterization of β-D-(1 → 3, 1 → 6)-linked glucans using NMR spectroscopy
AU - Kim, Young Teck
AU - Kim, Eun Hee
AU - Cheong, Chaejoon
AU - Williams, David L.
AU - Kim, Chan Wha
AU - Lim, Seung Taik
N1 - Funding Information:
This work was supported by Ministry of Health and Welfare (to S.T.L., project No. HMP-97-D-4-0017 and by the Ministry of Science and Technology (to C.C., project No. 99-1-01-03-A-043), Republic of Korea.
PY - 2000/9/22
Y1 - 2000/9/22
N2 - Nondestructive structural analysis of a series of β-D-(1 → 3, 1 → 6)- linked glucans (laminaran, curdlan, yeast glucan, scleroglucan, etc.) was performed using two-dimensional NMR spectroscopy. The relative ratios of H-1 at different AGUs provided the information about DP(n) and DB. The α-, and β-anomeric protons on reducing terminals were assigned at 5.02 ~ 5.03 ppm (J 3.6 ~ 3.7 Hz), and 4.42 ~ 4.43 ppm (J 7.6 ~ 7.9 Hz), respectively, whereas the H-1 protons of internal AGUs and β-(1 → 6)-branched AGUs appeared at 4.56 ~ 4.59 ppm (J 7.6 ~ 7.8 Hz), and 4.26 ~ 4.28 ppm (J 7.6 ~ 10.6 Hz), respectively, in a mixed solvent of 6:1 Me2SO-d6-D2O at 80°C. In the solvent, the OH peaks were eliminated from the spectra allowing the H-1 protons to appear clearly. In addition, the nonreducing terminal H-1 and H-1 at the AGU next to reducing terminal could be assigned at 4.45 ~ 4.46 ppm (J 7.8 ~ 7.9 Hz), and 4.51 ~ 4.53 ppm (J 7.8 Hz), respectively. The DP(n) of the laminaran was 33 (polydispersity 1.12) and the DB was 0.07. The number of glucosyl units in the side chain of laminaran is more than one. The DP(n) and DB of the water-insoluble yeast glucan were 228 and 0.003, respectively. However the DP(n) of water soluble yeast glucan phosphate and curdlan was changed upon the number of freeze-drying processes and the content of water in the mixed solvent, respectively. And the DB of those were calculated as 0.02 and 0, respectively. The DB of scleroglucan was precisely calculated as 0.33, compared with the previously reported data. The H-1s at different AGUs of the various β-D-(1 → 3, 1 → 6)-linked glucans having different DB can be exactly assigned by their chemical shifts in the mixed solvent system. This NMR analysis can be effectively used to determine the DP and DB of polysaccharides in a simple and non-destructive manner. (C) 2000 Elsevier Science Ltd.
AB - Nondestructive structural analysis of a series of β-D-(1 → 3, 1 → 6)- linked glucans (laminaran, curdlan, yeast glucan, scleroglucan, etc.) was performed using two-dimensional NMR spectroscopy. The relative ratios of H-1 at different AGUs provided the information about DP(n) and DB. The α-, and β-anomeric protons on reducing terminals were assigned at 5.02 ~ 5.03 ppm (J 3.6 ~ 3.7 Hz), and 4.42 ~ 4.43 ppm (J 7.6 ~ 7.9 Hz), respectively, whereas the H-1 protons of internal AGUs and β-(1 → 6)-branched AGUs appeared at 4.56 ~ 4.59 ppm (J 7.6 ~ 7.8 Hz), and 4.26 ~ 4.28 ppm (J 7.6 ~ 10.6 Hz), respectively, in a mixed solvent of 6:1 Me2SO-d6-D2O at 80°C. In the solvent, the OH peaks were eliminated from the spectra allowing the H-1 protons to appear clearly. In addition, the nonreducing terminal H-1 and H-1 at the AGU next to reducing terminal could be assigned at 4.45 ~ 4.46 ppm (J 7.8 ~ 7.9 Hz), and 4.51 ~ 4.53 ppm (J 7.8 Hz), respectively. The DP(n) of the laminaran was 33 (polydispersity 1.12) and the DB was 0.07. The number of glucosyl units in the side chain of laminaran is more than one. The DP(n) and DB of the water-insoluble yeast glucan were 228 and 0.003, respectively. However the DP(n) of water soluble yeast glucan phosphate and curdlan was changed upon the number of freeze-drying processes and the content of water in the mixed solvent, respectively. And the DB of those were calculated as 0.02 and 0, respectively. The DB of scleroglucan was precisely calculated as 0.33, compared with the previously reported data. The H-1s at different AGUs of the various β-D-(1 → 3, 1 → 6)-linked glucans having different DB can be exactly assigned by their chemical shifts in the mixed solvent system. This NMR analysis can be effectively used to determine the DP and DB of polysaccharides in a simple and non-destructive manner. (C) 2000 Elsevier Science Ltd.
KW - Glucan phosphate
KW - NMR spectroscopy
KW - Scleroglucan
KW - β-D-(1 → 3, 1 → 6)-linked glucan
UR - http://www.scopus.com/inward/record.url?scp=0034703218&partnerID=8YFLogxK
U2 - 10.1016/S0008-6215(00)00105-1
DO - 10.1016/S0008-6215(00)00105-1
M3 - Article
C2 - 11072840
AN - SCOPUS:0034703218
VL - 328
SP - 331
EP - 341
JO - Carbohydrate Research
JF - Carbohydrate Research
SN - 0008-6215
IS - 3
ER -