title: Novel glycosylated mycosporine-like amino acids with radical scavenging activity from the cyanobacterium Nostoc commune.
abstract: Mycosporine-like amino acids (MAAs) are UV absorbing pigments, and structurally distinct MAAs have been identified in taxonomically diverse organisms. Two novel MAAs were purified from the cyanobacterium Nostoc commune, and their chemical structures were characterized. An MAA with an absorption maximum at 335 nm was identified as a pentose-bound porphyra-334 derivative with a molecular mass of 478 Da. Another identified MAA had double absorption maxima at 312 and 340 nm and a molecular mass of 1,050 Da. Its unique structure consisted of two distinct chromophores of 3-aminocyclohexen-1-one and 1,3-diaminocyclohexen and two pentose and hexose sugars. These MAAs had radical scavenging activity in vitro; the 1050-Da MAA contributed approximately 27% of the total radical scavenging activities in a water extract of N. commune. These results suggest that these glycosylated MAAs have multiple roles as a UV protectant and an antioxidant relevant to anhydrobiosis in N. commune.
authors.affiliation: Division of Biological Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Matsui
authors.forename: Ehsan
authors.initials: E
authors.lastname: Nazifi
authors.forename: Shinpei
authors.initials: S
authors.lastname: Kunita
authors.forename: Naoki
authors.initials: N
authors.lastname: Wada
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsugo
authors.forename: Toshio
authors.initials: T
authors.lastname: Sakamoto
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D003512:Cyclohexanones / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry; D006031:Glycosylation; D050501:Nostoc commune / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: C569122:1050-Da MAA; C569121:478-Da MAA; D000596:Amino Acids; D003512:Cyclohexanones; D016166:Free Radical Scavengers; C421025:porphyra-334; D005998:Glycine