title: Sun-screening bioactive compounds mycosporine-like amino acids in naturally occurring cyanobacterial biofilms: role in photoprotection.
abstract: OBJECTIVE
  To investigate the occurrence of UV sunscreening biomolecules and their role in photoprotection in cyanobacterial biofilms growing in brightly lit habitats with high UV fluxes.
  
  
  RESULTS
  High performance liquid chromatography with photodiode-array and mass spectrometry revealed the presence of mycosporine-like amino acids (MAAs) shinorine (λ(max) 334 nm, m/z 333), porphyra-334 (λ(max) 334 nm, m/z 347), mycosporine-glycine (λ(max) 310 nm, m/z 246) and palythinol (λ(max) 332 nm, m/z 303). Two unknown MAAs with λ(max) at 320 (m/z 289) and 329 nm (m/z 318) were also found. Biosynthesis of MAAs was found to increase with increase in exposure time under UV radiation. The MAAs from biofilms showed efficient radical scavenging activity as well as photoprotective potential on the survival of UV-treated Escherichia coli cells.
  
  
  CONCLUSIONS
  Biosynthesis of photoprotectants is an important mechanism to prevent photodamage in Cyanobacteria. UV-induction and photoprotective function of MAAs may facilitate them to perform important ecological functions under harsh environmental conditions.
  
  
  CONCLUSIONS
  There are very few reports on qualitative and quantitative characterization of different MAAs in cyanobacterial biofilms. Due to strong UV absorption and photoprotective function, MAAs may be used as an active ingredient in cosmetic and other pharmaceutical industries.
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.|BRD School of Biosciences, Sardar Patel University, Vallabh Vidyanagar, India.
authors.forename: R P
authors.initials: RP
authors.lastname: Rastogi
authors.affiliation: BRD School of Biosciences, Sardar Patel University, Vallabh Vidyanagar, India.
authors.forename: D
authors.initials: D
authors.lastname: Madamwar
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
authors.forename: A
authors.initials: A
authors.lastname: Incharoensakdi
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism; D018441:Biofilms / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology / Q000528:radiation effects; D003512:Cyclohexanones / Q000032:analysis / Q000378:metabolism; D003514:Cyclohexylamines / Q000032:analysis / Q000378:metabolism; D005998:Glycine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D013473:Sunscreening Agents / Q000032:analysis / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D000596:Amino Acids; D003512:Cyclohexanones; D003514:Cyclohexylamines; D013473:Sunscreening Agents; C421025:porphyra-334; C494891:shinorine; D005998:Glycine
keywords: Cyanobacteria; UV radiation; induction; mycosporine-like amino acids; photoprotection