Phycoerythrobilin

Phycoerythrobilin

(3E)-phycoerythrobilin
Names
IUPAC name (2R,3E,16R)-18-ethenyl-3-ethylidene-1,2,3,15,16,19,22,24-octahydro-2,7,13,17-tetramethyl-1,19-dioxo-21H-biline-8,12-dipropanoic Acid
Identifiers
CAS Number	18097-67-1  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:85659
ChemSpider	16741434  Y
MeSH	phycoerythrobilin
PubChem CID	20057005
InChI InChI=1S/C33H38N4O6/c1-7-20-19(6)32(42)37-27(20)14-25-18(5)23(10-12-31(40)41)29(35-25)15-28-22(9-11-30(38)39)17(4)24(34-28)13-26-16(3)21(8-2)33(43)36-26/h7-8,14-15,19,26,35H,2,9-13H2,1,3-6H3,(H,36,43)(H,37,42)(H,38,39)(H,40,41)/b20-7+,27-14-,28-15-/t19-,26-/m1/s1 Y Key: IGJXAXFFKKRFKU-NDGVYKEISA-N Y
SMILES C=CC1=C(C)[C@@H](CC2=N/C(=C\c3[nH]c(/C=C4\NC(=O)[C@H](C)\C4=C/C)c(C)c3CCC(=O)O)C(CCC(=O)O)=C2C)NC1=O
Properties
Chemical formula	C33H38N4O6
Molar mass	586.689 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Phycoerythrobilin is a red phycobilin, i.e. an open tetrapyrrole chromophore ^[1] found in cyanobacteria and in the chloroplasts of red algae, glaucophytes and some cryptomonads. Phycoerythrobilin is present in the phycobiliprotein phycoerythrin, of which it is the terminal acceptor of energy. The amount of phycoerythrobilin in phycoerythrins varies a lot, depending on the considered organism. In some Rhodophytes and oceanic cyanobacteria, phycoerythrobilin is also present in the phycocyanin, then termed R-phycocyanin. Like all phycobilins, phycoerythrobilin is covalently linked to these phycobiliproteins by a thioether bond.

Chemical structure

Phycoerythrobilin is a tetrapyrrole formed in nature by the catabolism of heme B via biliverdin. ^[2] Two geometric isomers of the compound have been reported, which differ only in the configuration of one sidechain. ^[3]

Biosynthesis

(E) and (Z)-phycoerythrobilin are products of porphyrin biosynthesis beyond heme B. They arise from its oxidation which cleaves the macrocyclic ring, giving biliverdin: ^[2]

heme B

 

 

 

 

 

 

biliverdin

Biliverdin is then reduced to give either the (E) or (Z) isomers of phycoerythrobilin, for example by phycoerythrobilin synthase: ^{[2] [4]}

biliverdin

 

 

 

 

 

 

(3E) isomer

or

 

(3Z) isomer

References

1. Chapman, David J.; Cole, W. J.; Siegelman, Harold W. (1967). "Structure of phycoerythrobilin". Journal of the American Chemical Society . 89 (23): 5976–5977. Bibcode:1967JAChS..89.5976C. doi:10.1021/ja00999a058. ISSN   0002-7863.
2. Neilan, Brett; Passarini, Michel Rodrigo Zambrano; Singh, Prashant Kumar; Kumar, Ajay, eds. (2023). Cyanobacterial Biotechnology in the 21st Century. Springer Nature. pp. 89–90. doi:10.1007/978-981-99-0181-4. ISBN   978-981-99-0180-7.
3. Compare PubChem entry for (3E) isomer with entry for (3Z) isomer
4. Dammeyer, Thorben; Bagby, Sarah C.; Sullivan, Matthew B.; Chisholm, Sallie W.; Frankenberg-Dinkel, Nicole (2008). "Efficient Phage-Mediated Pigment Biosynthesis in Oceanic Cyanobacteria". Current Biology. 18 (6): 442–448. doi:10.1016/j.cub.2008.02.067. PMID   18356052.