Stability Analyses by HPLC-MS of Guanitoxin Isolated from Sphaerospermopsis torques-reginae

Autor(es)

Fernandes, Kelly A. ^[1] ; Dorr, Felipe Augusto ^[1] ; Pinto, Ernani ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut, Dept Anal Clin & Toxicol, Lab Toxinas & Prod Nat Algas LTPNA, Ave Prof Lineu Prestes, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Ctr Energia Nucl Agr CENA, Ave Centenario 303, BR-13416000 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 32, n. 8, p. 1559-1567, AUG 2021.
• Citações Web of Science: 0

Resumo

Guanitoxin (GNT) is a natural organophosphate produced by some species of freshwater cyanobacteria, which inhibits the active site of acetylcholinesterase, preventing the hydrolysis of cholinesterases and consequently causing serious disturbances in the neuromuscular system. Despite having a chemical structure like synthetic organophosphates, there is still no analytical standard available for environmental and freshwater monitoring. Therefore, this study investigated the stability of GNT under different storage conditions, pH, and temperature. The toxin is produced by the cyanobacterium Sphaerospermopsis torques-reginae and monitored by liquid chromatography coupled to mass spectrometry (LC-MS) and LC-MS/MS for the identification and verification of its stability. The main degradation product formed is the hydroxy-amino-guanidinic derivative of the toxin. The results also indicate that GNT is stable in acidic medium (pH = 3.0), but can gradually degrade at room temperature (> 23 ºC) over a period of 96 h. Lyophilized biomass of S. torques-reginae containing GNT remained stable when stored in a refrigerator below 4 ºC. In addition, the extraction yield is higher when prepared from fresh S. torques-reginae cells than from lyophilized material. Thus, the results shown here contribute with valuable information for studies that aim at the isolation, identification, and monitoring of GNT in samples of raw water and cyanobacterial blooms. (AU)

• Processo FAPESP: 14/50420-9 - Metabólitos secundários produzidos por micro-organismos aquáticos e impacto na qualidade de frutos do mar e de peixes de água doce
• Beneficiário: Ernani Pinto Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular