Anatoxin-a, a toxic alkaloid from Anabaena flos-aquae NRC-44h

Abstract

A toxic alkaloid, anatoxin-a, has been isolated from mass cultures of a unialgal clone, NRC-44h, of the freshwater blue-green algae Anabaena flos-aquae (Lyngb.) de Bréb., and its structure determined.

Biosynthesis of two dihydropyrrole-polyketides from a marine-derived Penicillium citrinum

“…After toxicity evaluation with unlabeled sodium acetate, added to the growth medium of P. citrinum (up to 5 g L -1 ), for which no morphology alterations of the fungus in the growth medium or even alterations in the production yield of 1 and 2 were observed, experiments with sodium[1-13 C]acetate, sodium[1,2-13 C 2 ]acetate, sodium [2,[3][4][5][6][7][8][9][10][11][12][13] C 2 ]propionate, [methyl-13 C]methionine, [U-13 C 5 ]ornithine and [U-13 C 5 ]proline were performed. 13 C-Labeled precursors were added at the fourth day of growth, at a final concentration of 1 mg mL -1 for each precursor, using previously optimized growth conditions.…”

“…Pyrrole, dihydropyrrole (pyrroline) and tetrahydropyrrole (pyrrolidine) alkaloids constitute a unique class of secondary metabolites, which include several bioactive members such as the tropane alkaloids, 1 tambjamines [2][3][4] and prodigiosin, 5 anatoxin-a, 6 as well as 2-alkyl or 2,5-dialkyl-branched pyrrolidine and pyrroline ant chemical defenses. 7 However, such alkaloids are extremely rare in fungi, the only examples found in literature 8 include the dihydropyrrole-bearing peptide brevigellin isolated from Penicillium brevicompactum, 9 the dihydropyrrole b-keto amides 1 and 2 also isolated from P. brevicompactum, [10][11][12] the mildly antibiotic scalusamides A−C (3-5), which have been isolated from a marine-derived P. citrinum, 13 as well as the tetrahydropyrrole-citrinin conjugate perinadine A, isolated from P. citrinum of marine origin.…”

Bibliometric analysis of research on microcystins in China and worldwide from 1991 to 2011

“…"Microcystin-LR," "Nodularin," and "Cylindrospermopsin" are three kinds of well-studied hepatotoxins due to their potential carcinogenicity [6]. "Anatoxin-A" belongs to neurotoxin [30]. All these toxins mentioned belong to "Cyanotoxins."…”

Aspectos toxicológicos e químicos da Anatoxina-a e seus análogos

“…Os principais gêneros produtores de cianotoxinas são Anabaena, Microcystis, Oscillatoria, Aphanizomenon, Nodularia e Cylindrospermopsis 7 . No grupo das neurotoxinas estão saxitoxinas e seus análogos, pertencentes às chamadas "paralytic shellfish poisoning" (PSP) que provocam bloqueio nos canais de sódio na membrana dos neurônios 8 ; Anatoxina-a(s) ("s" de salivação), um organofosforado natural que age como inibidor irreversível da acetilcolinesterase 9 e Anatoxina-a, um potente agonista nicotínico da acetilcolina, cuja estrutura foi a primeira a ser elucidada dentro desta classe 10 . As estruturas químicas destas neurotoxinas estão representadas na Figura 1.…”

“…Além disso, muitas espécies podem biossintetizar toxinas, aumentando ainda mais o risco à população 3,4 . Os incidentes toxicológicos relacionados com as cianotoxinas incluem intoxicações de seres humanos e animais, trazendo como conseqüência, morte de gado, animais selvagens, animais domésticos e até humanos em todo o mundo ; Anatoxina-a(s) ("s" de salivação), um organofosforado natural que age como inibidor irreversível da acetilcolinesterase 9 e Anatoxina-a, um potente agonista nicotínico da acetilcolina, cuja estrutura foi a primeira a ser elucidada dentro desta classe 10 . As estruturas químicas destas neurotoxinas estão representadas na Figura 1.…”