RESUMO
Phytochemical investigations were performed on the EtOAc-soluble fraction of the whole plant of the sky flower (Duranta repens) which led to the isolation of the iridoid glycosides 1-6. Their structures were elucidated by both 1D and 2D NMR spectroscopic analysis. All the compounds showed potent antioxidative scavenging activity in four different tests, with half maximal inhibitory concentration (IC(50)) values in the range 0.481-0.719 mM against DPPH radicals, 4.07-17.21 µM for the hydroxyl radical (·OH) inhibitory activity test, 43.3-97.37 µM in the total reactive oxygen species (ROS) inhibitory activity test, and 3.39-18.94 µM in the peroxynitrite (ONOO(-)) scavenging activity test. Duranterectoside A (1) displayed the strongest scavenging potential with IC(50) values of (0.481 ± 0.06 mM, 4.07 ± 0.03, 43.30 ± 0.05, 3.39 ± 0.02 µM) for the DPPH radicals, ·OH inhibitory activity test, total ROS inhibitory activity test and the ONOO(-) scavenging activity test, respectively.
Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Glicosídeos Iridoides/farmacologia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Compostos de Bifenilo/antagonistas & inibidores , Flores/química , Sequestradores de Radicais Livres/química , Radical Hidroxila/antagonistas & inibidores , Glicosídeos Iridoides/química , Masculino , Ácido Peroxinitroso/antagonistas & inibidores , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/antagonistas & inibidores , Verbenaceae/químicaRESUMO
The CHCl(3)-soluble fraction of the whole plant of Duranta repens showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum, with IC(50) values of 8.5 ± 0.9 and 10.2 ± 1.5 µg/mL, respectively. From this fraction, two new flavonoid glycosides, 7-O-α-d-glucopyranosyl-3,4'-dihydroxy-3'-(4-hydroxy-3-methylbutyl)-5,6-dimethoxyflavone (1) and 7-O-α-d-glucopyranosyl(6'''-p-hydroxcinnamoyl)-3,4'-dihydroxy-3'-(4-hydroxy-3-methylbutyl)-5,6-dimethoxyflavone (2), along with five known flavonoids, 3,7,4'-trihydroxy-3'-(4-hydroxy-3-methylbutyl)-5,6-dimethoxyflavone (3), 3,7-dihydroxy-3'-(4-hydroxy-3-methylbutyl)-5,6,4'-trimethoxyflavone (4), 5,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-3,6,4'-trimethoxyflavone (5), 3,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-buten-yl)-5,6,4'-trimethoxyflavone (6), and 7-O-α-d-glucopyranosyl-3,5-dihydroxy-3'-(4''-acetoxy-3''-methylbutyl)-6,4'-dimethoxyflavone (7), have been isolated as anti-plasmodial principles. Their structures were deduced by spectroscopic analysis including 1D and 2D NMR techniques. The compounds (1-7) showed potent anti-plasmodial activities against D6 and W2 strains of Plasmodium falciparum, with IC(50) values in the range of 5.2-13.5 µM and 5.9-13.1 µM, respectively.
Assuntos
Antimaláricos/isolamento & purificação , Antimaláricos/farmacologia , Descoberta de Drogas , Flavonoides/farmacologia , Glicosídeos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Verbenaceae/química , Antimaláricos/química , Resistência a Medicamentos , Flavonoides/química , Flavonoides/isolamento & purificação , Glicosídeos/química , Glicosídeos/isolamento & purificação , Concentração Inibidora 50 , Malária Falciparum/tratamento farmacológico , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
Phytochemical investigations on the chloroform and ethyl acetate soluble fractions of the roots of the Daphne oleoids led to the isolation of the coumarin glycosides 1-6. Compound 5 with IC50 values 22.05 and 26.30 microM repectively, was found to be the most active of these compounds when screened against Bacillus pasteurii and jack bean urease enzymes in a concentration-dependent fashion.
Assuntos
Daphne/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Urease/antagonistas & inibidores , Inibidores Enzimáticos/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Relação Estrutura-Atividade , Urease/metabolismoRESUMO
Ramosine, a new sesquiterpene lactone, was isolated from the chloroform fraction of Amberboa ramosa and the structure was assigned as 4beta-(hydroxymethyl)-3beta,4alpha-dihydroxy-8alpha-[(S)-3-hydroxy-2-ethylenepropionyloxy]-1alphaH, 5alphaH,6betaH,7alphaH,11betaH,11alpha-methylguaia-10(14)-en-6, 12-olide by extensive NMR studies.