Banca de DEFESA: RICARDO ALEXANDRE DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RICARDO ALEXANDRE DOS SANTOS
DATE: 30/07/2021
TIME: 13:30
LOCAL: Google Meet
TITLE:

Nitroso-Bodipy as a selective fluorescent probe for glutathione determination.

KEY WORDS:

Biothiols. BODIPY. Probe. Spectrofluorescence. Blood plasma.

PAGES: 74
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SUMMARY:

Metabolic processes generate the so-called oxidative stress, causing a disruption of redox signaling and control, which may lead to molecular damage. Among the most important antioxidants are biothiols, especially glutathione, which, together with its antioxidant enzymes, help regulate the redox system. This work describes the development of a simple and efficient analytical methodology based on the spectrofluorescence of structurally modified BODIPYs for the quantification of glutathione in its reduced form (GSH) in biological samples, in order to estimate its redox condition. The method consists of measuring the intensity of fluorescence emitted by the adult GSH-probe, formed in a reactional environment, proportional to the concentration of GSH in the system. The experimental conditions were optimized: pH value = 7.5 in Britton Robinson 10 mM buffer, concentration of the BODIPY probe modified by nitrosylation to 3-nitrosyl-8-(2,6-dichlorophenyl)-BODIPY (QHM - 300) at 5 µM, adjustment of ionic strength, using NaCl at a concentration of 100 mM. With the kinetic study, a minimum reaction time of 15 min was verified in the system, so that there was complete formation of the fluorescent adult, while the stability study demonstrated the photostability of the probe without changing the fluorescence intensity within a period of 60 min. The analytical parameters were determined: linear range of 0-5 µM, detection limit (LOD) of 61.4 nM and relative standard deviations (RSD) of 3.9% and 4.4% for concentrations of 1 µM and 5 µM, respectively. In the quantification of GSH, protein albumin, cysteine and fatty acids interfered with the method, changing the fluorescence signal of the system, compared to the blank containing only GSH, simulating the application conditions in blood plasma.

BANKING MEMBERS:
Externo à Instituição - Flávio da Silva Emery - USP
Presidente - 1006306 - JADRIANE DE ALMEIDA XAVIER
Interno - 1613338 - JOSUE CARINHANHA CALDAS SANTOS
Interna - 2120103 - MARILIA OLIVEIRA FONSECA GOULART
Interno - 1697766 - WANDER GUSTAVO BOTERO