Estudo químico de erythroxylum suberosum (erythroxylaceae) frente às catepsinas K, L e V
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Data
2014-07-17
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Universidade Federal de Goiás
Resumo
This work describes the chemical study
of E. suberosum, aiming to elucidate structures of secondary metabolites in the
leaves, stem and roots. Cathepsins assays were used to evaluate in vitro
activity of extracts, fractions and isolated compounds, using fluorogenic
substrate ZFR-MCA. These enzymes, also known as lysossomal cysteine
peptidases are involved in many physiological processes, and are associated
with many pathological conditions. Cathepsins K, L and V are involved in the
development of diseases such as osteoporosis, skin cancer and
atherosclerosis, respectively. Based on pathological processes in which
cathepsins are involved, the search for specific inhibitors can be a new
approach for the treatment these diseases. The study of ethanolic extract from
leaves led to the identification of four flavonoids belonging to the flavonol class:
quercetin and its derivatives 3-O-monoglycosides hyperin and isoquercitrin, and
3-O-diglycosides, ombuin-3-rutinoside, all previously reported for this species.
The mixture of flavanols, catechin and epicatechin were isolated from ethanolic
extract from roots, besides the fatty ester of sitosterol. The mixture of steroids
campesterol, stigmasterol and β-sitosterol were identified from the stem extract.
This study also suggests the presence of tropane alkaloids, tropacocaine and
nortropacocaine, in the ethanolic extract from leaves of E. suberosum, reported
for the first time in this species. In the evaluation for cathepsins K, L and V, the
extracts (concentration of 50 mg/mL), showed significant inhibition of all
enzymes with percentage inhibition values above 60%. The fractions showed
significant activity against cathepsin V and L when evaluated at concentrations
of 5 and 50 mg/mL. The quercetin flavonol showed IC50 value of 2.2 ± 0.2 μM
against cathepsin V and low affinity for cathepsins K and L (100 μM). This is an
important result since literature reports for flavonoids as inhibitors of cathepsin
V are quite limited.
Descrição
Palavras-chave
Produtos naturais, Erythroxylaceae, Erythroxylum suberosum, Catepsinas, Natural products, Erythroxylaceae, Erythroxylum suberosum, Cathepsins
Citação
NASCIMENTO, Michelle Nauara Gomes do. Estudo químico de erythroxylum suberosum (erythroxylaceae) frente às catepsinas K, L e V. 2014. 104 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Goiânia, 2014.