Dinogunellin
Group of chemical compounds
From Wikipedia, the free encyclopedia
Dinogunellins are unusual toxic phospholipids found in the roe of some fishes, and is one of the best studied ichthyotoxin.[1] These phospholipids could be found as a complex with non-toxic proteins like in the cabezon toxin or in the lipostichaerin.[2][3]
Occurrence
Dinogunellins were detected in the mature roe of four fishes: the cabezon or marbled sculpin Scorpaenichthys marmoratus, [2] the blennies Stichaeus grigorjewi [1][3] and Stichaeus nozawae, [4] and the killifish Fundulus heteroclitus. [4]
The presence of dinogunellins has been discarded in the roe of the carp Cyprinus carpio, the sculpin Hemitripterus villosus, the blenny Lumpenus fowleri,[4] and the lamprey Lapetra japonica.[5]
Structure
Dinogunellins are unusual phospholipids having a nucleotide instead of the typical glycerol in their structure. They consist of an adenine nucleotide, with a 2-aminosuccinimide attached to the phosphorus moiety and a fatty acid attached to the oxygen from either the C2' or the C3' of the sugar moiety.[1] The fatty acid chain could be either the eicosapentaenoic acid (Dinogunellin-A and Dinogunellin-B) or the stearidonic acid (Dinogunellin-C and Dinogunellin-D).[1] In consequence, Dinogunellin-A and Dinogunellin-B have the same molecular formula (C34H49N8O9P) and molecular weight (744.8 g/mol), and so do Dinogunellin-C and Dinogunellin-D (C32H47N8O9P; 718.7 g/mol).
Pharmacology
When intraperitoneally administered to mice, dinogunellins have a mean lethal dose (LD50) of 25 mg/kg.[3] Dinogunellins are also orally toxic to mice and guinea pigs and has also deleterious effects on humans.[6] A few hours after ingestion, humans develop abrupt onset diaphoresis, chills, abdominal pain and cramping, with nausea and vomiting followed by voluminous, non-bloody diarrhea.[7]
Analysis made on the cabezon toxin showed that its effects start 12 hours after administration and is characterized by several signs such as diarrhea, nasal discharge, and death.[8] In addition, cabezon toxin showed cytotoxicity on fibroblast in culture.[8][9] Besides, toxin administration causes an increase in white cell number, but with a decrease in lymphocytes associated with the observation of spleen necrosis. [9]