title: Exclusive observation of the (13R)-enantiomer of chlorophyll-c from a diatom Chaetoseros calcitrans.
abstract: Chiral high-performance liquid-chromatography (HPLC) for quantitative analysis of optically active chlorophyll(Chl)-c molecules, which are seen in many marine photosynthetic organisms, was developed. Chls-c have a single asymmetric carbon at the 13(2)-position, so their stereoisomers are (13(2)R)- and (13(2)S)-enantiomers. After the separation of each enantiomer, the stereochemistry was unambiguously characterized using its circular dichroism spectrum in comparison with that of the structure-related compound, protochlorophyllide-a. Moreover, Chls-c were carefully extracted from the cells of a diatom Chaetoseros calcitrans without racemization and were subjected to the chiral HPLC. The results clearly demonstrated that naturally occurring Chl-c molecules are enantiomerically pure (13(2)R)-forms, which are generally found in photosynthetically active chlorophyllous pigments.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Mizoguchi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tamiaki
mesh_terms: D002734:Chlorophyll / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D017377:Diatoms / Q000737:chemistry*; D009904:Optical Rotation; D011521:Protochlorophyllide; D013237:Stereoisomerism
chemical_list: D002734:Chlorophyll; C064041:chlorophyll c; D011521:Protochlorophyllide