| Names | |
|---|---|
| IUPAC name 2-[3-[2-[(2S)-butan-2-yl]-6-(1H-indol-3-yl)-3-oxo-7H-imidazo[2, 1-c]pyrazin-8-yl]propyl]guanidine | |
| Other names Cypridina luciferin, cypridinid luciferin, Vargula luciferin | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
PubChem CID | |
| UNII | |
CompTox Dashboard (EPA) | |
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| Properties | |
| C22H27N7O | |
| Molar mass | 405.506 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Vargulin, [1] also called Cypridinid luciferin, [2] Cypridina luciferin, or Vargula luciferin, is the luciferin found in the ostracod Cypridina hilgendorfii , also named Vargula hilgendorfii . [3] 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.
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. [4] The compound was first isolated and purified to crystals by Osamu Shimomura. [5] The structure of the compound was confirmed some years later. [6] Feeding experiments suggest that the compound is synthesized in the animal from three amino-acids: tryptophan, isoleucine, and arginine. [7]
Vargulin is oxidized by the Vargula luciferase, [8] a 62 kDa enzyme, to produce blue light at 462 nm (max emission, detected with a 425 to 525 nm filter). The vargulin does not cross react with luciferases using coelenterazine or Firefly luciferin.
Vargulin (with the associated luciferase) has applications in biotechnology:
Although less stable, the Cypridina system is useful because can be used in multiplex assays with other (red-emitting) luciferin assays.