title: Preparative isolation and structural characterization of sucrose ester isomers from oriental tobacco.
abstract: To date, the structures of the sucrose tetraester (STE) isomers, a main kind of sucrose esters (SEs) in Solanum, have not been conclusively assigned. In this study, three groups of STE isomers with the molecular weight 650, 664 and 678 (designated as STE I, STE II and STE III, respectively) have been isolated and purified from the oriental tobacco-Komotini Basma using a semi-preparative RP-HPLC method. The full characterization of the isomers in the three groups of STE were investigated for the first time by MS (HRMS, MS(2)) and NMR ((1)H, (13)C, HSQC) spectroscopy combined with alkaline hydrolysis and STE derivation experiments. The STE III (a single compound) was confirmed as a known sucrose tetraester. Furthermore, the STE II was found to contain three isomers and the structures were first unambiguously established as 6-O-acetyl (2,3 or 2,4 or 3,4)-di-O-3-methylvaleryl-(4 or 3 or 2)-O-2-methylbutyryl-α-d-glucopyranosyl-β-d-fructofuranoside. Finally, the STE I was discovered to contain seven isomers and the structures were elucidated as 6-O-acetyl (2 or 3 or 4)-O-3-methylvaleryl-(3,4 or 2,4 or 2,3)-di-O-2-methylbutyryl-α-d-glucopyranosyl-β-d-fructofuranoside, 6-O-acetyl (2 or 3 or 4)-O-3-methylvaleryl-(3,4 or 2,4 or 2,3)-di-O-isovaleryl-α-d-glucopyranosyl-β-d-fructofuranoside and 6-O-acetyl (2,3 or 2,4 or 3,4)-di-O-3-methylvaleryl-(4 or 3 or 2)-O-isobutyryl-α-d-glucopyranosyl-β-d-fructofuranoside (one of the 3 isomers).
authors.affiliation: Department of Applied Chemistry, College of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, PR China.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Jia
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wang
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Zhu
authors.forename: Chunping
authors.initials: C
authors.lastname: Xu
authors.forename: Duobin
authors.initials: D
authors.lastname: Mao
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004952:Esters / Q000737:chemistry* / Q000302:isolation & purification; D006868:Hydrolysis; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013395:Sucrose / Q000737:chemistry*; D014026:Nicotiana / Q000737:chemistry*
chemical_list: D004952:Esters; D013395:Sucrose