Scytonemin

Scytonemin

Names
IUPAC name (3E,3'E)-3,3'-bis(4-hydroxybenzylidene)-[1,1'-bi(cyclopenta[b]indole)]-2,2'(3H,3'H)-dione
Other names Scytonemin
Identifiers
CAS Number	152075-98-4 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:90127 N
ChemSpider	16736974 N
InChI InChI=1S/C36H20N2O4/c39-21-13-9-19(10-14-21)17-25-33-29(23-5-1-3-7-27(23)37-33)31(35(25)41)32-30-24-6-2-4-8-28(24)38-34(30)26(36(32)42)18-20-11-15-22(40)16-12-20/h1-18,39-40H/b25-17+,26-18+ N Key: CGZKSPLDUIRCIO-RPCRKUJJSA-N N InChI=1/C36H20N2O4/c39-21-13-9-19(10-14-21)17-25-33-29(23-5-1-3-7-27(23)37-33)31(35(25)41)32-30-24-6-2-4-8-28(24)38-34(30)26(36(32)42)18-20-11-15-22(40)16-12-20/h1-18,39-40H/b25-17+,26-18+ Key: CGZKSPLDUIRCIO-RPCRKUJJBK
SMILES C1=CC=C2N=C\3C(=C(C(=O)/C3=C/C4=CC=C(C=C4)O)C5=C6C(=NC7=CC=CC=C67)/C(=C\C8=CC=C(C=C8)O)/C5=O)C2=C1
Properties
Chemical formula	C36H20N2O4
Molar mass	544.6 g/mol
Appearance	brown solid
Solubility	25mg/ml DMSO
UV-vis (λmax)	325-425nm
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

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

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.