Results 201 to 210 of about 23,269,289 (245)

ChemInform Abstract: Synthesis of Anatoxin‐a.

ChemInform, 1987
AbstractBromination of the azabicyclononanol (Ib) prepared from (Ia) gives the amino ketone (II) which is converted to N‐methylanatoxin‐a (Va) by abis‐homologation procedure using first Wittig‐Horner reaction with (III) and then an oxygenation/reduction step.
J. R. WISEMAN, S. Y. LEE
openaire   +1 more source

Synthesis of (±)-Anatoxin-a and Analogues

Tetrahedron, 2000
A new and highly efficient synthesis of the potent nicotinic acetylcholine receptor agonist, anatoxin-a and its analogues is described, which uses a s-lactam ring opening-transannular cyclisation sequence to set up the bridged bicyclic framework of the natural product.
Philip J Parsons, Nicholas P Camp, Neil Edwards, L Ravi Sumoreeah   +3 more
openaire   +1 more source

Anatoxin‐a occurrence and potential cyanobacterial anatoxin‐a producers in Spanish reservoirs¹

Journal of Phycology, 2007
The presence of anatoxin‐a (ANA) in Mediterranean region freshwaters has been reported only recently, and this work presents the first survey for ANA on a national scale in such waters. Fourteen reservoirs were sampled over a distance of 550 km from northeast to southwest Spain. Genera of cyanobacteria with ANA‐producing members in other countries were
David Carrasco, Enrique Moreno, Thamar Paniagua, Caridad de Hoyos, Lars Wormer, Daniel Sanchis, Samuel Cirés, Delia Martín‐del‐Pozo, Geoffrey A. Codd, Antonio Quesada   +9 more
openaire   +1 more source

Determinism of anatoxin-a production in Phormidium-dominated biofilms of a regulated river (Ain, France).

Harmful Algae
Benthic cyanobacteria have been increasingly held responsible for bird and mammal deaths along riverbanks in the last decades. However, little is known about the environmental conditions that favor their development, spatiotemporal dynamics and ...
Charlotte Robichon, Delphine Latour, Fanny Perrière, Sylvain Dolédec, J. Robin   +4 more
semanticscholar   +1 more source

The co-existence of Microcoleus strains with gene variations in the anatoxin-a biosynthesis cluster can explain the different toxin profiles observed in freshwater benthic mats.

Toxicon
Distinct anatoxin profiles can occur in Microcoleus-dominated benthic mats. Metagenomic data from a dihydrohomoanatoxin-a-producing mat revealed two co-occurring Microcoleus strains with variations in the anatoxin biosynthesis gene cluster.
Cecilio Valadez-Cano, A. Reyes-Prieto, Lindsay H. Johnston, Yannan Huang, Hannah M. Morris, Lydia Zamlynny, André M Comeau, Daniel G. Beach, Rob C. Jamieson, Janice Lawrence   +9 more
semanticscholar   +1 more source

An efficient synthesis of (+)-anatoxin-a.

Tetrahedron: Asymmetry, 1992
Abstract An efficient synthesis (38 % overall yield in 8 steps starting from 2) of the potent neurotoxin (+)-anatoxin-a is described. The key step involves the stereoselective addition of 5-hexenylcopper to the chiral N-acyliminium ion 2a .
Marco Skrinjar, Carita Nilsson, Lars-G. Wistrand   +2 more
openaire   +1 more source

Analyzing the neurotoxic effects of anatoxin-a and saxitoxin in zebrafish larvae.

Aquatic Toxicology
Global warming due to climate change, as well as freshwater eutrophication caused by anthropogenic activities are responsible, among other factors, for an increasing occurrence of harmful algal blooms (HABs) in aquatic systems.
Irene Romero-Alfano, E. Prats, Xavier Ortiz Almirall, D. Raldúa, Cristián Gómez-Canela   +4 more
semanticscholar   +1 more source

Acute toxicity of dihydroanatoxin-a from Microcoleus autumnalis in comparison to anatoxin-a.

Chemosphere, 2020
The cyanobacterium Microcoleus autumnalis grows as thick benthic mats in rivers and is becoming increasingly prevalent around the world. M. autumnalis can produce high concentrations of anatoxins and ingestion of benthic mats has led to multiple dog ...
Jonathan Puddick, R. van Ginkel, C. Page, J. Murray, Hannah E. Greenhough, Joel Bowater, A. Selwood, S. Wood, M. Prinsep, P. Truman, R. Munday, S. Finch   +11 more
semanticscholar   +1 more source

Total Synthesis of Pinnamine and Anatoxin-a via a Common Intermediate. A Caveat on the Anatoxin-a Endgame

The Journal of Organic Chemistry, 2005
[reaction: see text] This paper describes the total synthesis of the naturally occurring alkaloids pinnamine (1) and anatoxin-a (2) from a common enantiomerically pure intermediate (7) easily available from pyroglutamic acid. The synthesis of enantiopure pinnamine proceeded in 10 steps and 4.8% overall yield, and the route was flexible enough to allow ...
Thomas, Hjelmgaard, Inger, Søtofte, David, Tanner   +2 more
openaire   +2 more sources

Combined toxic effects of anatoxin-a and microcystin-LR on submerged macrophytes and biofilms.

Journal of Hazardous Materials, 2020
Hazardous substances, such as anatoxin-a and microcystin-LR, are released into the aquatic environment during cyanobacterial blooms, causing significant ecological risk.
Qi Li, Peng Gu, Chen Zhang, Xin Luo, Hao Zhang, Jibiao Zhang, Zheng Zheng   +6 more
semanticscholar   +1 more source