Teleocidin A1

Lyngbyatoxin A from the marine cyanobacterium Moorea producens (formerly Lyngbya majuscula) is known as the causative agent of "swimmer's itch" with its highly inflammatory effect. A new toxic compound was isolated along with lyngbyatoxin A from an ethyl acetate extract of M. producens collected from Hawaii. Analyses of HR-ESI-MS and NMR spectroscopies revealed the isolated compound had the same planar structure with that of lyngbyatoxin A. The results of optical rotation and CD spectra indicated that the compound was a new lyngbyatoxin A derivative, 12-epi-lyngbyatoxin A (1). While 12-epi-lyngbyatoxin A showed comparable toxicities with lyngbyatoxin A in cytotoxicity and crustacean lethality tests, it showed more than 100 times lower affinity for protein kinase Cδ (PKCδ) using the PKCδ-C1B peptide when compared to lyngbyatoxin A.

Pendolmycin, isolated from Nocardiopsis, is a compound structurally similar to teleocidin A, one of the 12-O-tetradecanoylphorbol-13-acetate (TPA)-type tumor promoters. Pendolmycin has a C5 dimethyl allyl group attached to C-7 of (-)-indolactam-V, whereas teleocidin A has a C10 linalyl group attached to the molecule. The structure-activity relationships of a hydrophobic moiety attached to (-)-indolactam-V were studied in four compounds, (-)-indolactam-V, pendolmycin, teleocidin A and newly synthesized 7-(nerolidyl)-(-)-indolactam-V in tests on inhibition of the specific [3H]TPA binding to a particulate fraction of mouse skin, activation of protein kinase C and induction of both adhesion of HL-60 cells and ornithine decarboxylase in mouse skin. The potencies of the compounds for these activities increased mainly depending on the length of the hydrophobic group. Pendolmycin had a tumor-promoting activity on mouse skin initiated with a single application of 7,12-dimethyl-benz[a]anthracene, and its potency was just between those of (-)-indolactam-V and teleocidin A. The role of the hydrophobic moiety is discussed with particular emphasis on the results obtained with 7-(nerolidyl)-(-)-indolactam-V.

Lyngbya majuscula is a benthic filamentous marine cyanobacterium, which in recent years appears to have been increasing in frequency and size of blooms in Moreton Bay, Queensland. It has a worldwide distribution throughout the tropics and subtropics in water to 30m. It has been found to contain a variety of chemicals that exert a range of biological effects, including skin, eye and respiratory irritation. The toxins lyngbyatoxin A and debromoaplysiatoxin appear to give the most widely witnessed biological effects in relation to humans, and experiments involving these two toxins show the formation of acute dermal lesions. Studies into the epidemiology of the dermatitic, respiratory and eye effects of the toxins of this organism are reviewed and show that Lyngbya induced dermatitis has occurred in a number of locations. The effects of aerosolised Lyngbya in relation to health outcomes were also reported. Differential effects of bathing behaviour after Lyngbya exposure were examined in relation to the severity of health outcomes. The potential for Lyngbya to exhibit differential toxicologies due to the presence of varying proportions of a range of toxins is also examined. This paper reviews the present state of knowledge on the effects of Lyngbya majuscula on human health, ecosystems and human populations during a toxic cyanobacterial bloom. The potential exists for toxins from Lyngbya majuscula affecting ecological health and in particular marine reptiles.