title: Sequence analysis of the sulfated rhamno-oligosaccharides derived from a sulfated rhamnan.
abstract: Three sulfated rhamno-oligosaccharides, designated O1, O2 and O3, were obtained by mild acid hydrolysis of the sulfated rhamnan and purified by gel-permeation chromatography. On the basis of one- and two-dimensional nuclear magnetic resonance (1D, 2D NMR) spectroscopic analyses, the oligosaccharide O1 was characterized to be α-L-Rhap-(2SO4)-(1→3)-α-L-Rhap. The fragmentation pattern of the homogeneous disaccharide in the product ion spectra was recognized by negative-ion electrospray tandem mass spectrometry with collision-induced dissociation (ES-CID MS/MS). With the principles established, the sequences of the oligosaccharides O2 and O3 were deduced to be α-L-Rhap-(2SO4)-(1→3)-α-L-Rhap-(1→3)-α-L-Rhap, and α-L-Rhap-(2SO4)-(1→3)-α-L-Rhap-(1→3)-α-L-Rhap-(1→3)-α-L-Rhap (2SO(4)), respectively. The investigation demonstrated that the sulfated rhamnan-derived oligosaccharides were novel sulfated oligosaccharides different from those of other polysaccharides-degraded from algae, and it could be possible to determine the sequence of the sulfated rhamno-oligosaccharides directly from the glycosidic cleavage fragmentation in the product ion spectra.
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drug and Food, Ocean University of China, Qingdao 266003, People's Republic of China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.forename: Wenjun
authors.initials: W
authors.lastname: Mao
authors.forename: Yin
authors.initials: Y
authors.lastname: Chen
authors.forename: Sumei
authors.initials: S
authors.lastname: Ren
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Qi
authors.forename: Yanli
authors.initials: Y
authors.lastname: Chen
authors.forename: Chunqi
authors.initials: C
authors.lastname: Zhao
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Chunyan
authors.initials: C
authors.lastname: Wang
authors.forename: Cong
authors.initials: C
authors.lastname: Lin
authors.forename: Mengxia
authors.initials: M
authors.lastname: Yan
authors.forename: Jimiao
authors.initials: J
authors.lastname: Shan
mesh_terms: D002236:Carbohydrate Conformation; D000460:Chlorophyta / Q000737:chemistry*; D003837:Deoxy Sugars / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D017421:Sequence Analysis / Q000379:methods; D013463:Sulfuric Acid Esters / Q000737:chemistry*
chemical_list: D003837:Deoxy Sugars; D008351:Mannans; D009844:Oligosaccharides; D013463:Sulfuric Acid Esters; C065836:rhamnan