18 research outputs found
Composição química, atividades inibidora da acetilcolinesterase e antifúngica de Pera glabrata (Schott) Baill. (Euphorbiaceae)
Pera glabrata (Schott) Baill. was selected for this study after showing a preliminary positive result in a screening of Atlantic Forest plant species in the search for acetylcholinesterase inhibitors and antifungal compounds. The bioassays were conducted with crude ethanol extract of the leaves using direct bioautography method for acetylcholinesterase and antifungal activities. This extract was partitioned with hexane, chloroform and ethyl acetate solvents. The active chloroform fraction was submitted to silica gel chromatography column affording 12 groups. Caffeine, an alkaloid, which showed detection limits of 0.1 and 1.0 µg for anticholinesterasic and antifungal activities, respectively, was isolated from group nine. After microplate analyses, only groups four, nine, 10, 11 and 12 showed acetylcholinesterase inhibitory activity of 40% or higher. The group 12 was purified by preparative layer chromatography affording four sub-fractions. Two sub-fractions from this group were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. The first sub-fraction showed anticholinesterasic activity and contained two major compounds: 9-hydroxy-4-megastigmen-3-one (84%) and caffeine (6%). The second sub-fraction presented five major compounds identified as 9-hydroxy-4-megastigmen-3-one, isololiolide, (-) loliolide, palmitic acid and lupeol and did not show activity.Pera glabrata (Schott) Baill. foi selecionada para este estudo a partir de uma triagem de espécies vegetais da Mata Atlântica na busca de substâncias com atividades anticolinesterásica e antifúngica. A técnica da bioautografia direta foi utilizada para a detecção das atividades anticolinesterásica e antifúngica. O extrato etanólico bruto obtido das folhas foi particionado com hexano, clorofórmio e acetato de etila. A fração clorofórmica ativa foi fracionada por cromatografia em coluna de sílica gel fornecendo 12 grupos. Do grupo nove foi isolado o alcalóide cafeína com limites de detecção de 0,1 e 1,0 µg para as atividades anticolinesterásica e antifúngica, respectivamente. Após bioensaio em microplaca, somente os grupos quatro, nove, 10, 11 e 12 apresentaram inibição da acetilcolinesterase maior ou igual a 40%. O grupo 12 foi purificado por cromatografia em camada delgada preparativa de sílica gel fornecendo quatro sub-frações. Duas sub-frações deste grupo foram analisadas por cromatografia a gás-espectrometria de massas e cromatografia a gás com detector de ionização de chama. A primeira sub-fração contém dois compostos majoritários: 9-hidroxi-4-megastigmen-3-ona (78%) e cafeína (6%), e apresentou atividade anticolinesterásica. A segunda sub-fração contém cinco compostos principais identificados como 9-hidroxi-4-megastigmen-3-ona, isololiolida, (-) loliolida, ácido palmítico e lupeol e não apresentou atividade.FapespCNPq - PibicCapes - Prodo
Saponinas antifúngicas de Swartzia langsdorffii
Chromatographic fractionation of the EtOH extract from the leaves of Swartzia langsdorffii afforded the pentacyclic triterpenes oleanolic acid and lupeol, and two saponins: oleanolic acid 3-sophoroside and the new ester 3-O-b-D-(6'-methyl)-glucopyranosyl-28-O-b-D-glucopyranosyl-oleanate. Their structures were elucidated from spectral data, including 2D NMR and HRESIMS experiments. Antifungal activity of all isolated compounds was evaluated, using phytopathogens Cladosporium cladosporioides and C. sphaerospermum, and human pathogens Candida albicans, C. krusei, C. parapsilosis and Cryptococcus neoformans
Cardiac glycosides isolated from the Indian-snuff, Maquira sclerophylla Ducke
The hydroalcoholic extract of the powdered bark of the Indian-snuff Maquira sclerophylla Ducke was purified by column chromatography in silica-gel and the major cardenolide isolated from preparative TLC was identified by 1H-NMR, 1 2 C-NMR and IR analyses. The spectra showed that the active substance has strophanthidin as aglicone.UNESP Departamento de FisiologiaUFMA Departamento de QuímicaEscola Paulista de Medicina Departamento de Farmacologia Setor de Produtos NaturaisUNIFESP, EPM, Depto. de Farmacologia Setor de Produtos NaturaisSciEL
Sympathomimetic effects of Scoparia dulcis L and catecholamines isolated from plant extracts
The herb Scoparia dulcis L. is used in Brazilian folk medicine to treat bronchitis, gastric disorders, haemorrhoids, insect bites and skin wounds, and in oriental medicine to treat hypertension. A previous study has shown that extracts of S. dulcis have analgesic and anti-inflammatory properties in this work the sympathomimetic activity of an ethanolic extract of Scoparia dulcis L. has been investigated in rodent preparations in-vivo and in-vitro.Administration of the extract (0.5-2 mg kg(-1), i.v.) to anaesthetized rats produced dose-related hypertension blocked by the alpha-adrenoceptor antagonist prazosin (1 mg kg(-1)). Partition of the extract in chloroform-water yielded an aqueous phase 20 times more potent than the extract; this produced hypertension in either reserpine-treated or pithed rats. in untreated and reserpine-treated rats the same fraction (1-3 x 10(3) mu g mL(-1)) produced concentration-dependent contractions of the vas deferens musculature parallel to those obtained with noradrenaline (10(-8)-10(-4) M). Prazosin (10(-7) M) reduced the maximum contractile effect of the aqueous fraction, and shifted the concentration-response curves for noradrenaline to the right. The aqueous fraction (25 and 50 mu g mL(-1)) increased the inotropism of electrically driven left atria of rats, the effect being blocked by propranolol (0.4 mu g mL(-1)). in preparations of guinea-pig tracheal rings the aqueous fraction (1-3 x 10(3) mu g mL(-1)) relaxed the muscle contraction induced by histamine (10(-4) M) in proportion to the concentration. The effect was antagonized competitively by propranolol (1.5 mu M), High-performance liquid-chromatographic analysis of the aqueous fraction revealed the presence of both noradrenaline and adrenaline in the plant extract.The results indicated that both catecholamines may account for the hypertensive and inotropic effects obtained after parenteral administration of S. dulcis extracts. This sympathomimetic activity is, however, unrelated to the previously reported analgesic and anti-inflammatory properties of the plant extract, but may explain its effectiveness upon topical application in the healing of mucosal and skin wounds.UNIV FED SAO PAULO,ESCUELA PAULISTA MED,DEPT PHARMACOL,NAT PROD SECT,BR-04044020 SAO PAULO,BRAZILUNIV FED SAO PAULO,ESCUELA PAULISTA MED,DEPT PHARMACOL,NAT PROD SECT,BR-04044020 SAO PAULO,BRAZILWeb of Scienc
Phytochemistry
p.617–619A bioassay monitored fractionation of a chloroform extract from the aerial parts of Baccharis trimera yielded a mixture that blocked the Ca2+-induced contractions of KCl- depolarized rat portal vein preparations. Pharmacological tests of two pure compounds isolated from the mixture revealed the dilactonic clerodane diterpene as the active compound
Leaf extracts of Casearia sylvestris and Casearia decandra affect growth and production of ligninolytic enzymes in wood decay basidiomycetes
ABSTRACT White-rot basidiomycetes are able to deteriorate wood products and be pathogenic to living trees, requiring, thus requiring control. The tropical flora is an important source of eco-friendly antifungal compounds; however, the knowledge on how leaf extracts affect the fungal physiology is limited. Therefore, in the present work we investigated the influence of ethanolic leaf extracts of Casearia sylvestris and C. decandra at 0.1 mg mL-1 on the production of ligninolytic enzymes by Trametes villosa, Ganoderma australe and Pycnoporus sanguineus. Overall, the extracts inhibited the mycelial growth and the production of biomass. Additionally, C. sylvestris extract reduced the production of manganese peroxidase and laccase; however, the exposure to C. decandra extract resulted in variable responses. Therefore, enzymes related to lignin degradation are potential targets to control wood decay fungi by plant bioactive compounds, as their ability to colonize the substrate may be impaired