Lyngbyatoxins - the swimmer’s itch disease causing agents.

Lyngbyatoxin is a secondary metabolite produced by the marine Moorea producens called also Lyngbya majuscula and Lyngbya wolley. These are cosmopolitan benthic cyanobacteria that start their growth on the marine sediments. They can be distinguished in the litoral zone as a surface or streamers mat as reported in Fig 1 and 2 (Speziale, 1991).

Lyngbyatoxin was investigated after some dermatitis cases, due by reports of “swimmer’s itch” which have been in direct contact with the cyanobacteria in Ohau (Hawaii). Moorea producens was considered the causative agent which exposure rapidly produced a skin irritation with burning sensation.

Therefore, other study demonstrated other chemical properties as a slight lipohilicity and high skin penetration potential. (Sanseverino et al.). In addition, L. majuscula and L. wolley not only can produce dermatotoxic alkaloids like lyngbyatoxin-a but also aplysiatoxin and debromoaplysiatoxin (Mynderse et al. 1977) and neurotoxic alkaloids like saxitoxins have been found as secondary metabolites (Carmichael et al.1977).

Lyngbyatoxin is an alkaloid with molecular formula of C₂₇H₃₉N₃O₂. It is structurally similar to the teleocidin A-1 while the teleocidin A-2 is the C19 epimer. Exist different variants of lyngbyatoxin like A, B, and C who differ in the position of the hydroxyl group. (Cardellina et al., 1979). Their structures were elucidated by Cardellina et al., which used a combination of IR spectroscopy and ¹H and ¹³C nuclear magnetic resonance (NMR).

At the moment no analytical methods have been set for the determination of lyngbyatoxin but lots of identification and screening method are available. Screening tests, which are simpler and most practical for consideration by water utilities, include: enzyme-linked immunosorbent assays (ELISA) for which commercial kits are commercially available and which are the most ubiquitous (Carmichael 2001), and protein phosphatase inhibition (PPI) assays.

Liquid chromatography-mass spectrometry (MC-MS) with electrospray ionization is widely used in the analysis of marine toxic compounds while, if necessary, higher resolution power can be found in other MS techniques such as hybrid Quadrupole Time-Of-Flight (QqTOF), Quadrupole Ion-Trap (QIT) or Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight (MALDI-TOF), providing higher mass resolution or intrinsic mass fragmentation pathway.

SMILES (Lyngbyatoxin A): CN([C@H]1C(C)C)C2=C3C(NC=C3C[C@@H](CO)NC1=O)=C([C@](C=C)(C)CC/C=C(C)/C)C=C2

References:

• Carmichael, W.W., (2001). Assessment of Blue-Green Algal Toxins in Raw and Finished Drinking Water. AWWA Research Foundation, Denver, Colo. 179 pages.
• Carmichael, W.W., (1997). The Cyanotoxins. In: Advances in Botanical Research, Vol. 27. Edited by J. Callow. London. Academic Press.
• Paerl H., Joyne J., O’Neil J., Paul V. and others. UNC-Chapel Hill Institute of Marine Sciences, Morehead City, NC. Website: www.unc.edu/ims/paerllab Accessed 26/11/2017
• Sanseverino I., Conduto António D., Loos R. and Lettieri T. Cyanotoxins: methods and approaches for their analysis and detection; EUR 28624; doi:10.2760/36186)
  Speziale B.J., E. Glenn Turner & Larry A. Dyck (1991) Physiological Characteristics of Vertically-Stratified Lyngbya wollei Mats, Lake and Reservoir Management, 7:1, 107-114
• Cardellina J.H., Marner F.J., Moore R.E. (1979) Seaweed dermatitis: structure of lyngbyatoxin A. Science, 204:4389, 193-195.
• Mynderse J.S., Moor R.E., Kashiwagi M., Norton T.R. (1977) Antileukemia activity in the Oscillatoriaceae: Isolation of debromoaplysia toxin from Lyngbya. Science, 196: 538–540.
• Botana L.M. Seafood and Freshwater Toxins: Pharmacology, Physiology, and Detection, third edition. CRC Press, 12 mar. 2014 – 1215.