Scytonemin

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Scytonemin
Scytonemin.png
Identifiers
CAS number 152075-98-4 YesY
ChEMBL CHEMBL505177 N
Properties
Molecular formula C36H20N2O4
Molar mass 544.6 g/mol
Appearance brown solid[1]
Solubility 25mg/ml DMSO
λmax 325-425nm
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Scytonemin is a biological pigment synthesized by many strains of cyanobacteria, including Calothrix sp.,[2] Lyngbya aestuarii,[3] and others. It was originally discovered in 1849, although the structure remained unsolved until 1993.[4] Scytonemin is believed to act as a bacterial sunscreen with a broad absorption from 325-425 nm and a separate maxima at 250 nm,[4] and its biosynthesis triggered by exposure to UV light.[5]

Biosynthesis[edit]

The biosynthesis in Lyngbya aestuarii was recently explored by Balskus, Case, and Walsh. It proceeds by the conversion of L-tryptophan to 3-indole pyruvic acid, followed by coupling to p-hydroxyphenylpyruvic acid. Cyclization of the resultant β-ketoacid yields a tricyclic ketone. Oxidation and dimerization yields the completed natural product. Three scytonemin biosynthetic enzymes are necessary, denoted as ScyA-C.[3]

Scytonemin biosynthesis in Lyngbya aestuarii.[3]

References[edit]

  1. ^ "Scytonemin CAS (152075-98-4)". Santa Cruz Biotechnology, Inc. Retrieved 2011-05-30. 
  2. ^ Dillon, Jesse G.; Castenholz, Richard W. (2003). "The synthesis of the UV-screening pigment, scytonemin, and photosynthetic performance in isolates from closely related natural populations of cyanobacteria (Calothrix sp.)". Environmental Microbiology 5 (6): 484–91. doi:10.1046/j.1462-2920.2003.00436.x. PMID 12755715. 
  3. ^ a b c Balskus, Emily P.; Case, Rebecca J.; Walsh, Christopher T. (2011). "The biosynthesis of cyanobacterial sunscreen scytonemin in intertidal microbial mat communities". FEMS Microbiology Ecology: 1–11. doi:10.1111/j.1574-6941.2011.01113.x. 
  4. ^ a b Proteau, P. J.; Gerwick, W. H.; Garcia-Pichel, F.; Castenholz, R. (1993). "The structure of scytonemin, an ultraviolet sunscreen pigment from the sheaths of cyanobacteria". Experientia 49 (9): 825–9. doi:10.1007/BF01923559. PMID 8405307. 
  5. ^ M. Bandaranayake, Wickramasinghe (1998). "Mycosporines: are they nature’s sunscreens?". Natural Product Reports 15 (2): 159–72. doi:10.1039/A815159Y. PMID 9586224. 

External links[edit]

  • Balskus, Emily P.; Case, Rebecca J.; Walsh, Christopher T. (2011). "The biosynthesis of cyanobacterial sunscreen scytonemin in intertidal microbial mat communities". FEMS Microbiology Ecology: no–no. doi:10.1111/j.1574-6941.2011.01113.x.