31 research outputs found
Immunobiological properties of selected natural and chemically modified phenylpropanoids
Effects of natural and structurally transformed lignans compared with stilbenes or stilbenoids on production of nitric oxide (NO) triggered by lipopolysaccharide (LPS) and interferon-Îł (IFN-Îł), tested under in vitro conditions using murine resident peritoneal macrophages, are reviewed. Relation between the molecular structure and immunobiological activity was investigated, and implication of substituents, double bond stereochemistry, or cyclic attachments (double bond geometry fixation) was assessed. The focus was on lignans and stilbenoids because they were originally selected for a joint project of common interest to phytochemical and pharmacological investigation and because they represent well interesting and universally attractive groups of polyphenols with a feasible potential for therapeutic or nutraceutic utilization
Ecdysteroid 7,9(11)-dien-6-ones as potential photoaffinity labels for ecdysteroid binding proteins
Three ecdysteroid 7,9(11)-dien-7-ones (dacryhainansterone, 25-hydroxydacryhainansterone and kaladasterone) were prepared by dehydration of the corresponding 11a-hydroxy ecdysteroids (ajugasterone C, turkesterone and muristerone A, respectively). The biological activities of the dienones in the Drosophila melanogaster B(II) cell bioassay, which reflect the affinity for the ecdysteroid receptor complex, showed that the dienones retain high biological activity. Irradiation at 350 nm of the ecdysteroid dienones (100 nM) with bacterially-expressed dipteran and lepidopteran ecdysteroid receptor proteins (DmEcR/DmUSP or CfEcR/CfUSP), followed by loading with [(3)H]ponasterone A revealed that irradiation of dacryhainansterone or kaladasterone resulted in blocking of >70% of the specific binding sites. Thus, ecdysteroid dienones show considerable potential as photoaffinity analogues for ecdysteroid binding proteins
Wine As Medicine throughout Ages and Within Changes of Knowledge
Wine with its curative effect was, is, and within certain limits definitely will remain in the mind and memory of pople a medium, worthy of attention of professionals, as well as amateur consumers, longing for good health and carefree aging. Through the ages, the wine has been mostly considered a medicine. However, the current drug definition shifted this part of its identity among the bioactive dietary supplements - nutraceuticals with health benefits. The actual therapeutic value of wine, however, remained identical
Chemical factors affecting the taste and medicinal activity of wine
The wine is presented as a complicated multi-component, and permanently varying (maturing) natural product, with unique properties, acquired from several sources, e.g. the grape origin, the growth locality, the enological processes, as well as the qualified evaluation with a feedback to all factors shaping the character and quality of wine. Chemical components are regarded as generators of perceivable sensory (taste) properties of wine, as well as providers of its pharmacological effects and medicinal value, qualifying wine as active functional food additive (nutraceutical) with a significant impact on health
The quality of wine from the aspect of a chemist and sommelier
The wine substances are regarded not only as providers of perceivable sensory properties, but also as a basis of medicinel effects of wines. The wine is presented as an active functional food additive - nutraceutical, with significant impact on health
Spirostanol Saponins from Flowers of Allium Porrum and Related Compounds Indicating Cytotoxic Activity and Affecting Nitric Oxide Production Inhibitory Effect in Peritoneal Macrophages
Saponins, a diverse group of natural compounds, offer an interesting pool of derivatives with biomedical application. In this study, three structurally related spirostanol saponins were isolated and identified from the leek flowers of Allium porrum L. (garden leek). Two of them were identical with the already known leek plant constituents: aginoside (1) and 6-deoxyaginoside (2). The third one was identified as new component of A. porrum; however, it was found identical with yayoisaponin A (3) obtained earlier from a mutant of elephant garlic Allium ampeloprasun L. It is a derivative of the aginoside (1) with additional glucose in its glycosidic chain, identified by MS and NMR analysis as (2α, 3β, 6β, 25R)-2,6-dihydroxyspirostan-3-yl β-D-glucopyranosyl-(1 → 3)-β-D-glucopranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl]-(1 → 4)-β-D-galactopyranoside, previously reported also under the name alliporin. The leek native saponins were tested together with other known and structurally related saponins (tomatonin and digitonin) and with their related aglycones (agigenin and diosgenin) for in vitro cytotoxicity and for effects on NO production in mouse peritoneal cells. The highest inhibitory effects were exhibited by 6-deoxyaginoside. The obtained toxicity data, however, closely correlated with the suppression of NO production. Therefore, an unambiguous linking of obtained bioactivities of saponins with their expected immunobiological properties remained uncertain
Dielectric Properties and Breakdown of the Gate Oxide in the MOS Structure
The article treats the methodology of measuring the breakdown voltage on Si-based MOS structures. Identification of defects in the thin gate oxide is performed using the Weibull statistical analysis. By comparing the current and capacitance measurements on MOS structures we determined the influence of the defect charge in the oxide upon the parameters characterizing the breakdown. A higher occurrence of defects was correlated with elevated values of the flat band voltages. This verifies the hypothesis of an increased destruction of MOS structures caused by electrically active defects arising in the course of thermic oxidation and pre-oxidation treatment of the surface of silicon