title: Determination of proline enantiomers in honey and royal jelly by LC-UV.
abstract: The chiral separation and quantification of D-proline and L-proline in honey and royal jelly were examined by LC with UV detection. Most of the endogenous compounds existing in honey, such as sugars, were removed by using SPE cartridges containing C18 and strong cation-exchange sorbent. Other components, such as primary amino acids, were also removed by two-step derivatization with o-phthalaldehyde (OPA) and 9-fluorenylmethyl chloroformate (FMOC-CI). The components that were derivatized with OPA were separated from proline with a C18 cartridge. Proline was then converted into an FMOC derivative that could be subsequently measured by LC-UV. Sufficient chiral separation of D-proline and L-proline was achieved with an LC chiral column made of a beta-cyclodextrin phase in the polar organic-phase mode. The average recoveries of D-proline and L-proline from honey and royal jelly were in the range of 81.3-98.6% (RSD of < 1.8%). When this method was applied to commercial honey and royal jelly samples, L-proline was detected at concentrations of 369-1930 microg/g, whereas D-proline was not detected.
authors.affiliation: Hoshi University, Faculty of Pharmaceutical Sciences, Department of Analytical Chemistry, 2-4-41, Ebara, Shinagawa-ku, Tokyo 142-8501, Japan. k-saito@hoshi.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Saito
authors.forename: Jun
authors.initials: J
authors.lastname: Kohama
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Rie
authors.initials: R
authors.lastname: Ito
authors.forename: Masakazu
authors.initials: M
authors.lastname: Horie
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakazawa
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005227:Fatty Acids / Q000032:analysis*; D006722:Honey / Q000032:analysis*; D011392:Proline / Q000737:chemistry*; D014466:Ultraviolet Rays; D000099219:Royal Jelly
chemical_list: D005227:Fatty Acids; D011392:Proline; D000099219:Royal Jelly