Diterpenoids with inhibitory activity of nitrite production from Croton floribundus
sex, 20 mar 2020
Publicado por CIBFar
Queiroz, Suzana Aparecida S. 1 ; Pinto, Meri Emili F. 1 ; Bobey, Antonio F. 1 ; Russo, Helena M. 1 ; Batista, Andrea N. L. 2 ; Batista, Jr., Joao M. 3 ; Codo, Ana C. 4 ; Medeiros, Alexandra I. 4 ; Bolzani, Vanderlan S. 1
Croton floribundus Spreng. (Euphorbiaceae), popularly known as Capixinguí, stands out due to its widespread use in traditional medicine to treat wounds, syphilis, hemorrhoids, eye diseases and as a purgative.
Aim of the study
To characterize clerodanes diterpenes from C. floribundus and to evaluate the effects of the fraction and diterpenes (1–5) on inhibition of nitrite production.
Materials and methods
The hydroethanolic root extract of C. floribundus was fractionated on a solid phase extraction column to obtain the fraction named Fr80%. From this, five compounds were obtained and characterized. The absolute configuration of compound 1 was determined by a combination of electronic and vibrational circular dichroism spectroscopies. Additionally, compounds 1–5 were evaluated for their inhibitory effects on nitrite production induced by lipopolysaccharide (LPS) in RAW 264 macrophage cell.
Five clerodane diterpenoids were characterized, and the absolute stereochemistry of 1 was established as 3R,4R,5R,8R,9R,10S,12S. The IC50 values obtained through inhibition of nitrite production were 28.52 ± 2.21 μM (1), 40.26 ± 2.79 μM (2), 25.47 ± 2.16 μM (3), 35.78 ± 2.93 μM (4) and 40.58 ± 4.78 μM (5). In the tested concentrations, the samples presented low toxicity in macrophages.
Four new diterpenes were characterized from C. floribundus, these being croflorins A-D (1–4) and a known halimane (5). These compounds exhibited inhibitory effect on nitrite production.
1 Institute of Chemistry, Sao Paulo State University, Araraquara, 14800-060, Sao Paulo, Brazil
2 Institute of Chemistry, Fluminense Federal University, Niteroi, 24020-141, Rio de Janeiro, Brazil
3 Institute of Science and Technology, Federal University of Sao Paulo, Sao Jose Dos Campos, 12231-280, Sao Paulo, Brazil
4 School of Pharmaceutical Sciences, Sao Paulo State University, Araraquara, 01049-010, Sao Paulo, Brazil
Link to article: https://www.sciencedirect.com/science/article/pii/S0378874119322548?via%3Dihub
A new approach for identifying antagonism among fungi species and antifungal activity
sex, 20 mar 2020
Publicado por CIBFar
Silva, Airton Damasceno 1 ; Pepe Ambrozin, Alessandra Regina 2 ; Carneiro, Renato Lajarim 1 ; Vieira, Paulo Cezar 1, 3
New antifungals are increasingly needed due to the emergence of resistant fungal strains. Traditional antifungal assays are laborious and require significant amounts of samples. The present work presents a new proposal to evaluate antifungal activity and antagonism among fungal species, based on experiments of fungal culture and co-culture, 1H NMR profile of fungal culture extracts and chemometrics. In order to develop the work, six axenic cultures of fungi that infested fruits (Fusarium guttiforme, Pestalotiopsis diospyri, Phoma caricae-papayae, Colletotrichum horii, Phytophthora palmivora, and C. gloeosporioides), and co-cultures of all possible combination among them were performed (totalizing 63 experiments). All fungal extracts were evaluated by 1H NMR followed by Principal Component Analyses (PCA) in order to determine spectral dissimilarity among the extracts. Results showed that 1H NMR data evaluated by PCA were capable to predict both antagonism and antifungal activity. Traditional antifungal in vitro assays of active and inactive extracts were also performed in order to prove the prediction made by PCA. The obtained data showed that the approach is an outstanding tool to simultaneously obtain and evaluate bioactive compounds because: it was able to predict the activity of five different extracts in a collection of sixty-three, which would be much more difficult and time consuming if applied randomly; most important antifungal extracts are indicated by PCA; hundreds of traditional in vitro assays are avoid; and, the method is very time and money saving.
1 Department of Chemistry, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
2 Institute of Science and Technology, Federal University of Alfenas (Unifal-MG), Poços de Caldas, MG, Brazil
3 Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
Link to article: https://www.sciencedirect.com/science/article/pii/S0731708519319351?via%3Dihub