RESUMO
The objective of this study was to evaluate anti-inflammatory and antimicrobial activities of neovestitol and vestitol isolated from Brazilian red propolis (BRP). BRP ethanolic extract (EEP), neovestitol, and vestitol were evaluated by anti-inflammatory properties using a neutrophil migration assay. The antimicrobial activity was evaluated by minimal inhibitory and bactericidal concentrations (MIC and MBC) against Streptococcus mutans , Streptococcus sobrinus , Staphylococcus aureus , and Actinomyces naeslundii . Neovestitol, vestitol, and EEP inhibited neutrophil migration at a dose of 10 mg/kg. Regarding antimicrobial activity, neovestitol showed MICs ranging from <6.25 to 25-50 µg/mL and MBCs ranging from 25-50 to 50-100 µg/mL, while vestitol showed MICs ranging from 25-50 to 50-100 µg/mL and MBCs ranging from 25-50 to 50-100 µg/mL. Both isoflavonoids neovestitol and vestitol are consistent bioactive compounds displaying anti-inflammatory and antimicrobial activities that can strongly act in a low dose and concentration and have a promising potential to be applied in the pharmaceutical and food industries.
Assuntos
Anti-Infecciosos/isolamento & purificação , Anti-Inflamatórios/isolamento & purificação , Flavonoides/isolamento & purificação , Própole/química , Actinomyces/efeitos dos fármacos , Animais , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/farmacologia , Brasil , Flavonoides/farmacologia , Inflamação/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Streptococcus sobrinus/efeitos dos fármacosRESUMO
Chemical study of three medicinal plants: from leaves of Piper renitens (Miq.) Yunck, Piperaceae, and Siparuna guianensis Aubl., Siparunaceae, and from flowers of Alternanthera brasiliana (L.) Kuntze, Amaranthaceae, resulted in isolation of nine compounds: three steroids, β-sitosterol, stigmasterol from P. renitens and sitosterol-3-O-β-D-glucopyranoside from A. brasiliana, the diterpene kaurane ent-kauran-16α,17-diol from P. renitens, two derivatives kaempferol-methylether, kumatakenine (kaempferol-3,7-dimethylether) and kaempferol-3,7,3'-trimethylether from S. guianensis and three flavones, crysoeriol (5,7,4'-trihydroxy-3'-methoxyflavone), tricin (5,7,4'-trihydroxy-3',5'-dimethoxyflavone) and 7-O-β-D-glucopyranoside-5,4'-dihydroxy-3'-methoxyflavone from A. brasiliana. Compounds structures were determinate using 1D and 2D ¹H NMR and 13C spectral data, mass and IR spectra, comparing with literature data.
RESUMO
Colonial spiders evolved a differential prey-capture behaviour in concert with their venom chemistry, which may be a source of novel drugs. Some highly active tetrahydro-beta-carboline (THbetaC) toxins were recently isolated from the venom of the colonial spider Parawixia bistriata; the spiders use these toxins as part of their chemical arsenal to kill and/or paralyze preys. The major THbetaC compound isolated from this venom was identified as 6-hydroxytrypargine, also known as PwTX-I. Most natural compounds of animal origin occur in low abundance, and the natural abundance of PwTX-I is insufficient for complete functional characterization. Thus, PwTx-I was synthesized using a Pictet-Spengler condensation strategy, and the stereoisomers of the synthetic toxin were separated by chiral chromatography. The fraction of venom containing a mixture of three natural THbetaC toxins and enantiomers of PwTx-I were analyzed for inhibition of monoamine oxidase (MAO)-A and -B and for toxicity to insects. We reveal that the mixture of the natural THbetaC toxins, as well as the enantiomers of PwTx-I, were non-competitive inhibitors of MAO-A and MAO-B and caused potent paralysis of honeybees. The (-)-PwTX-I enantiomer is 2-fold more potent than the (+)-PwTX-I enantiomer in the assays performed.
Assuntos
Alcaloides Indólicos/toxicidade , Inibidores da Monoaminoxidase/farmacologia , Venenos de Aranha/química , Animais , Alcaloides Indólicos/isolamento & purificação , Cinética , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Monoaminoxidase/efeitos dos fármacos , Monoaminoxidase/metabolismo , Espectrometria de Fluorescência , Aranhas , EstereoisomerismoRESUMO
The (2,3)J(CH) dependence on dihedral angle (theta H--C--C--X) for cyclopentane derivatives was investigated. We observed that the combined use of experimentally obtained (2,3)J(CH) values and the theoretically determined dihedral angles between the corresponding nuclei can be used to infer the relative stereochemistry of the ring substituents in cyclopentane derivatives. There is a good correlation between the magnitude of (3)J(CH) and the dihedral angle between the hydrogen and the coupled carbon (R2 = 0.88).
Assuntos
Carbono/química , Ciclopentanos/química , Hidrogênio/química , Espectroscopia de Ressonância Magnética/normas , Simulação por Computador , Espectroscopia de Ressonância Magnética/métodos , Conformação Molecular , EstereoisomerismoRESUMO
Here we report the detailed measurement of long-range heteronuclear spin-spin coupling constants, especially 2, 3JCH spin-spin couplings for eight different cyclopentane derivatives. These 2, 3JCH constants were shown to be a useful tool in the determination of the relative stereochemistry in these rings. The coupling constant measurements reported here are based on two different experiments: a 2D heteronuclear correlation experiment named G-BIRDR, X-CPMG-HSQMBC and the 2D-coupled gHSQC {1H-13C} experiment
Assuntos
Ciclopentanos/química , Espectroscopia de Ressonância Magnética , Espectroscopia de Ressonância Magnética/normas , Estrutura Molecular , Padrões de ReferênciaRESUMO
A suitable intermediate for the synthesis of eremophilanes and bakkanes was prepared by a highly regioselective and stereoselective one-step synthesis through a niobium catalyzed Diels-Alder reaction. As a demonstration of the versatility of this intermediate, a total synthesis of (+/-)-bakkenolide A is described.
Assuntos
4-Butirolactona/análogos & derivados , 4-Butirolactona/química , Naftalenos/química , Nióbio/química , 4-Butirolactona/síntese química , Catálise , Estrutura Molecular , Sesquiterpenos Policíclicos , Sesquiterpenos , EstereoisomerismoRESUMO
Detailed measurements of long-range heteronuclear spin-spin coupling constants, especially (2, 3)J(CH) spin-spin couplings for various cyclopentane derivatives, are reported. The measurements are based on a 2D heteronuclear correlation experiment named G-BIRD(R, X)-CPMG-HSQMBC.