Complete Assignment of 1H and 13C Nuclear Magnetic Resonance Chemical Shifts of β-1,2-Linked Mannooligosaccharides Isolated from the Phosphomannan of the Pathogenic Yeast Candida albicans NIH B-792 Strain

To confirm correctness of the previous assignment study of H-i protons of β-1,2-linked mannooligosaccharides provided by Shibata et al. (Biochemistry 31, 5680-5686, 1992), anotber type of nonempirical assignment of the H-1 signals of be same oligosaccharides was achieved by adopting a sequential NMR assignment method that combines two-dimensional 1H-13C correlated spectroscopy, two-dimensional 1H-1H correlated spectroscopy, and two-dimensional heteronuclear multiple-bond connectivity. Based on the above results, all of the 1H and most of the 13C signals in each oligosaccharide could also be assigned. The results of the proton assignment study provided sufficient evidence to confirm the correctness of that obtained in the previous H-1 proton assignment study. Furthermore, the existence of a regularity rule between the order of mannose units and its 1H and 13C chemical shifts has been revealed.