title: Synthesis of chitosan 3,6-diphenylcarbamate-2-urea derivatives and their applications as chiral stationary phases for high-performance liquid chromatography.
abstract: Fourteen chitosan 3,6-diphenylcarbamate-2-urea derivatives were synthesized using well-deacetylated chitosan and the corresponding phenyl isocyanates. After coating them on silica gel, their chiral recognition abilities were evaluated as the chiral stationary phases (CSPs) for high-performance liquid chromatography. These coated-type CSPs exhibited different chiral recognitions depending on the position, nature, and number of the substituents introduced on the phenyl group, and the introduction of either an electron-withdrawing or an electron-donating substituent improved the chiral recognition of the CSPs. Among the CSPs, the 2-substituted CSPs showed low chiral recognition abilities, while those with 3,5-dimethyl and 3,5-dichloro substituents showed relatively higher chiral recognition abilities, which enabled the baseline separation of some racemates. The CSPs could be used with some eluents containing chloroform, which cannot be used for other polysaccharide-based CSPs. Some racemates were more efficiently resolved with these nonstandard eluents. The correlation between the chiral recognition ability and the chemical shifts of the N-H protons in the (1)H NMR spectra of the chitosan derivatives or the N-H frequencies in the IR spectra of the carbamate moieties was discussed.
authors.affiliation: Polymer Materials Research Center, Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Polymer Materials Research Center, Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China. Electronic address: shenjun@hrbeu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
authors.affiliation: Polymer Materials Research Center, Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Zuo
authors.affiliation: Polymer Materials Research Center, Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. Electronic address: okamoto@apchem.nagoya-u.ac.jp.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Okamoto
mesh_terms: D048271:Chitosan / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D048448:Phenylcarbamates / Q000138:chemical synthesis / Q000737:chemistry*; D058428:Silica Gel / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D048448:Phenylcarbamates; D058428:Silica Gel; D014508:Urea; D048271:Chitosan
keywords: Chiral recognition; Chiral stationary phases; Chitosan; HPLC; Phenylcarbamate