RESUMO
The extractive contents of three softwood species largely used in the wood industry, namely Abies alba (Silver fir), Picea abies (spruce) and Pseudotsuga menziesii (Douglas fir), have been determined quantitatively for knots and at different points chosen along their branches, before analysis using high-performance liquid chromatography coupled with Mass Spectrometry (HPLC-MS). The results indicated that branchwood samples located in close proximity to the stem present high contents of extractives similar to those recorded for the knots. HPLC analysis showed quite similar chemical compositions, indicating that first cm of the branches could be considered as an additional source of knotwood. The antibacterial, antifungal and antioxidant activities of knot's extractives have been investigated with the dual objective of better understanding the role of high levels of secondary metabolites present in the knot and evaluating their potential for biorefinery applications. The antioxidant activity study showed that crude extracts of Douglas fir knotwood presented higher radical scavenging activity levels than the extracts of Silver fir and spruce, which presented more or less the same activities. Silver fir and spruce knotwood extracts presented higher antibacterial activity levels than the Douglas fir knotwood extracts did, while Douglas fir knotwood extracts presented more fungal growth inhibition than the spruce and fir knotwood extracts did. The structure-activity relationships indicate that radical scavenging and antifungal activities are associated with a higher relative quantity of flavonoids in the crude extracts, while higher relative quantities of lignans are associated with antibacterial activity.
Assuntos
Picea , Pseudotsuga , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Antibacterianos/farmacologiaRESUMO
This paper reports the isolation and structural characterization of four new ent-kaurane derivatives from the Lamiaceae plant Sideritis hyssopifolia. Planar structures and relative configurations were determined using both mass spectrometry and nuclear magnetic resonance (1D and 2D). Absolute configurations were determined by comparing experimental and theoretical electronic circular dichroism spectra. The cytotoxic and microbial activities of all new compounds were tested. Compounds that were non-cytotoxic were further evaluated for anti-inflammatory activity.
Assuntos
Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Diterpenos do Tipo Caurano/farmacologia , Extratos Vegetais/farmacologia , Sideritis/química , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Diterpenos do Tipo Caurano/química , Diterpenos do Tipo Caurano/isolamento & purificação , Humanos , Modelos Moleculares , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Análise EspectralRESUMO
Re-investigation of the chemical composition of the annual plant Mitracarpus scaber Zucc. led to the identification of clarinoside, a new pentalogin derivative containing a rare quinovose moiety, and the known compound harounoside. While the planar structure was fully determined using tandem mass spectrometry (MS) and quantum mechanics (QM) calculations, the tridimensional structure was unravelled after isolation and NMR analysis. The absolute configuration was assigned by comparison of experimental and theoretical synchrotron radiation circular dichroism spectra. Both compounds were tested for anti-inflammatory activity, and compound 1 showed the ability to inhibit the production of interleukin-8 (Il-8) with an IC 50 value of 9.17 µ M.
Assuntos
Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Interleucina-8/metabolismo , Rubiaceae/química , Anti-Inflamatórios/química , Linhagem Celular , Dicroísmo Circular , Regulação para Baixo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Teoria Quântica , Síncrotrons , Espectrometria de Massas em Tandem , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Filamentous cyanobacteria of the genus Phormidium have been rarely studied for their chemical diversity. For the first time, the cultivable Phormidium autumnale was shown to produce a prenylated cyclic peptide named autumnalamide (1). The structure of this peptide was fully determined after a deep exploration of the spectroscopic data, including NMR and HRMS. Interestingly, a prenyl moiety was located on the guanidine end of the arginine amino acid. The absolute configurations of most amino acids were assessed using enantioselective GC/MS analysis, with (13)C NMR modeling being used for the determination of d-arginine and d-proline. The effects of 1 on sodium and calcium fluxes were studied in SH-SY5Y and hNav 1.6 HEK cells. When the Ca(2+) influx was stimulated by thapsigargin, strong inhibition was observed in the presence of 1. As a consequence, this compound may act by disrupting the normal calcium uptake of this organelle, inducing the opening of the mitochondrial permeability transition pore, which results in the indirect blockade of store-operated channels.
Assuntos
Cianobactérias/química , Peptídeos Cíclicos/isolamento & purificação , Peptídeos Cíclicos/farmacologia , Humanos , Estrutura Molecular , Peptídeos Cíclicos/química , Tapsigargina/farmacologiaRESUMO
The chemical investigation of the recently described Mediterranean Homoscleromorpha sponge Oscarella balibaloi revealed an original family of five closely related glucosylated sesterterpenes 1-4, named balibalosides. Their structure elucidation was mainly inferred from NMR and HRMS data analyses. Balibalosides differ by the pattern of acetyl substitutions on the three sugar residues linked to the same aglycone sesterterpenoid core. From a biosynthetic perspective, these compounds may represent intermediates in the pathways leading to more complex sesterterpenes frequently found in Dictyoceratida, a sponge Order belonging to Demospongiae, a clade which is phylogenetically distinct from the Homoscleromorpha. While steroid and triterpenoid saponins were already well known from marine sponges, balibalosides are the first examples of glycosilated sesterterpenes.
Assuntos
Poríferos/química , Sesterterpenos/química , Animais , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Mar Mediterrâneo , Sesterterpenos/isolamento & purificaçãoRESUMO
Ultra-high pressure liquid chromatography coupled to high resolution mass spectrometry (UHPLC-MS/MS) analysis of the organic extract obtained from the Mediterranean zoanthid Parazoanthus axinellae yielded to the identification of five new parazoanthines F-J. The structures were fully determined by comparison of fragmentation patterns with those of previously isolated parazoathines and MS/MS spectra simulation of in silico predicted compounds according to the metabolome consistency. The absolute configuration of the new compounds has been assigned using on-line electronic circular dichroism (UHPLC-ECD). We thus demonstrated the potential of highly sensitive hyphenated techniques to characterize the structures of a whole family of natural products within the metabolome of a marine species. Minor compounds can be characterized using these techniques thus avoiding long isolation processes that may alter the structure of the natural products. These results are also of interest to identify putative bioactive compounds present at low concentration in a complex mixture.