{{cs1 config|name-list-style=vanc}} {{chembox | ImageFile = Vargulin.svg | IUPACName=2-[3-[2-[(2''S'')-butan-2-yl]-6-(1''H''-indol-3-yl)-3-oxo-7''H''-imidazo[2, 1-''c'']pyrazin-8-yl]propyl]guanidine | OtherNames={{ubl|Cypridina luciferin|Cypridinid luciferin|Vargula luciferin}} |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 388868 | InChI = InChI=1S/C22H27N7O/c1-3-13(2)19-21(30)29-12-18(15-11-26-16-8-5-4-7-14(15)16)27-17(20(29)28-19)9-6-10-25-22(23)24/h4-5,7-8,11-13,26-27H,3,6,9-10H2,1-2H3,(H4,23,24,25)/t13-/m0/s1 | InChIKey = ZWPWSXGBDMGKKS-UHFFFAOYAG | CASNo=7273-34-9 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 761TM14Y84 | PubChem = 135398684 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C22H27N7O/c1-3-13(2)19-21(30)29-12-18(15-11-26-16-8-5-4-7-14(15)16)27-17(20(29)28-19)9-6-10-25-22(23)24/h4-5,7-8,11-13,26-27H,3,6,9-10H2,1-2H3,(H4,23,24,25) | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = ZWPWSXGBDMGKKS-UHFFFAOYSA-N | SMILES = O=C\3N4\C=C(\c2c1ccccc1[nH]c2)N/C(=C4/N=C/3[C@@H](C)CC)CCC/N=C(\N)N }} |Section2={{Chembox Properties | C=22 | H=27 | N=7 | O=1 | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= }} |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = }} }}
'''Vargulin''',<ref name="Campbell Herring 1990">{{cite journal | last1=Campbell | first1=A. K. | last2=Herring | first2=P. J. | title=Imidazolopyrazine bioluminescence in copepods and other marine organisms | journal=Marine Biology | publisher=Springer Science and Business Media LLC | volume=104 | issue=2 | year=1990 | issn=0025-3162 | doi=10.1007/bf01313261 | pages=219–225| bibcode=1990MarBi.104..219C | s2cid=84250053 }}</ref> also called '''Cypridinid luciferin''',<ref name="Morin2011">{{cite journal | last=Morin | first=James G. | title=Based on a review of the data, use of the term 'cypridinid' solves the Cypridina/Vargula dilemma for naming the constituents of the luminescent system of ostracods in the family Cypridinidae | journal=Luminescence | publisher=Wiley | volume=26 | issue=1 | year=2011 | issn=1522-7235 | doi=10.1002/bio.1282 | pages=1–4| pmid=19862683 }}</ref> '''Cypridina luciferin''', or '''Vargula luciferin''', is the luciferin found in the ostracod ''Cypridina hilgendorfii'', also named ''Vargula hilgendorfii''.<ref>{{cite book |author=Shimomura, O. |year=2006 |title=Bioluminescence: Chemical Principles and Methods |publisher=World Scientific Publishing |isbn=978-981-256-801-4}}</ref> These bottom dwelling ostracods emit a light stream into water when disturbed presumably to deter predation. Vargulin is also used by the midshipman fish, ''Porichthys''.
== History == A partial extraction procedure was developed in 1935 which involved reacting the compound with benzoyl chloride to allow it to be separated from the water-soluble components.<ref>{{cite journal | author = Anderson, RS | title = Studies on Bioluminescence : II. the Partial Purification of Cypridina Luciferin.| journal =The Journal of General Physiology| volume=19| issue=2 | pages=301–5 | year=1935 | pmid=19872927 | doi=10.1085/jgp.19.2.301 | pmc=2141430}}</ref> The compound was first isolated and purified to crystals by Osamu Shimomura.<ref>{{cite journal | author = Shimomura, O | author2 = Goto, T | author3 = Hirata, Y | title = Crystalline Cypridina Luciferin | journal = Bulletin of the Chemical Society of Japan | volume = 30 | issue = 8 | pages = 929–933 | year = 1957 | doi = 10.1246/bcsj.30.929 | hdl = 10069/20882 | hdl-access = free }}</ref> The structure of the compound was confirmed some years later.<ref>{{cite journal | author = Kishi Y, Goto | author2 = T, Hirata Y | author3 = Shiromura O | author4 = Johnson FH | author-link = Kishi Y | year = 1966 | title = Cypridina bioluminescence. I. Structure of Cypridina luciferin | journal = Tetrahedron Lett. | volume = 7 | issue = 29 | doi = 10.1016/S0040-4039(01)82806-9 | pages = 3427–3436 }}</ref> Feeding experiments suggest that the compound is synthesized in the animal from three amino-acids: tryptophan, isoleucine, and arginine.<ref>{{cite journal | author = Oba, Y | author2 = Kato, S | author3 = Ojika, M | author4 = Inouye, S | title=Biosynthesis of luciferin in the sea firefly, ''Cypridina hilgendorfii'': <small>L</small>-tryptophan is a component in Cypridina luciferin | journal = Tetrahedron Letters| volume=43| issue=12 | pages=2389–2392 | year=2002 | doi=10.1016/S0040-4039(02)00257-5 }}</ref>
== Biochemistry == Vargulin is oxidized by cypridina-luciferin 2-monooxygenase,<ref>{{cite journal | vauthors = Thompson EM, Nagata S, Tsuji FI | title = Cloning and expression of cDNA for the luciferase from the marine ostracod Vargula hilgendorfii | journal = Proceedings of the National Academy of Sciences | volume = 86 | issue = 17 | pages = 6567–71 | year = 1989 | pmid = 2771943 | pmc = 297885 | doi=10.1073/pnas.86.17.6567| bibcode = 1989PNAS...86.6567T | doi-access = free }}</ref><ref>{{cite journal | vauthors = Karpetsky TP, White EH | year = 1973 | title = The synthesis of Cypridina etioluciferamine and the proof of the structure of Cypridina luciferin | journal = Tetrahedron | volume = 29 | pages = 3761–3773 | doi = 10.1016/0040-4020(73)80193-0 | issue = 23 }}</ref><ref>{{cite journal | vauthors = Tsuji FI, ((Lynch RV III)), Stevens CL | year = 1974 | title = Some properties of luciferase from the bioluminescent crustacean, ''Cypridina hilgendorfii'' | journal = Biochemistry | volume = 13 | pages = 5204–5209 | pmid = 4433517 | doi = 10.1021/bi00722a024 | issue = 25 }}</ref> a 62 kDa enzyme, to produce blue light at 462 nm (max emission, detected with a 425 to 525 nm filter).
{{chemrxn|width=65%| {{chemrxn/cpd|vargulin }} {{chemrxn/arw|fwd_in={{chem2|O2}}|fwd_out={{chem2|CO2}} }} {{chemrxn/cpd|qid=Q27102268|caption=oxidized vargulin }} {{chemrxn/txt|+ hν }} }}
The vargulin does not cross react with luciferases using coelenterazine or Firefly luciferin.
== Uses == Vargulin (with the associated luciferase) has applications in biotechnology: * in a variety of assays, to report gene or gene expression after luciferase have been genetically introduced in cells, * to detect ATP, that is used in the vargulin/luciferase reaction (cell viability assays).<ref>{{cite web |title=Luciferase Reporters |url=https://www.thermofisher.com/vn/en/home/life-science/protein-biology/protein-biology-learning-center/protein-biology-resource-library/pierce-protein-methods/luciferase-reporters.html |website=thermofisher.com}}</ref>
Although less stable, the Cypridina system is useful because can be used in multiplex assays with other (red-emitting) luciferin assays.
==References== {{Reflist}}
==External links== *{{Commonscatinline}}
{{DEFAULTSORT:Viability Assay}} Category:Luciferins Category:Bioluminescence Category:Indoles Category:Guanidines Category:Imidazopyrazines Category:Lactams Category:Laboratory techniques Category:Microbiology techniques Category:Toxicology tests