Search results for " activity"
showing 10 items of 4540 documents
On the biochemical classification of yeast trehalases: Candida albicans contains two enzymes with mixed features of neutral and acid trehalase activi…
2009
Abstract Two enzymes endowed with trehalase activity are present in Candida albicans . The cytosolic trehalase (Ntc1p), displayed high activity in exponential phase regardless of the carbon source (glucose, trehalose or glycerol). Ntc1p activity was similar in neutral (pH 7.1) or acid (pH 4.5) conditions, strongly inhibited by ATP, weakly stimulated by divalent cations (Ca 2+ or Mn 2+ ) and unaffected in the presence of cyclic AMP. The Ntc1p activity decreased in stationary phase, except in glycerol-grown cultures, but the catalytic properties did not change. In turn, the cell wall-linked trehalase (Atc1p) showed elevated activity in resting cells or in cultures growing on trehalose or glyc…
Mannosyl transferases inSaccharomyces cerevisiae: Evidence for the occurrence of ectomannosyltransferase activity
1981
The subcellular distribution of mannosyltransferases inSaccharomyces cerevisiae was studied following the separation of the plasma membrane from other intracellular membranous systems. Most of the activity was linked to internal membranes, and the rest was located at the level of the plasma membrane. Yeast plasma membranes coated on their external face with concanavalin A when incubated with GDP-[U-14C]mannose incorporated 20% less [U-14C]mannose in glycoproteins and 110% more in glycolipids than plasma membranes alone. This suggested that part of the total mannosyltransferase activity of the plasma membrane is located on its outer surface. A significant incorporation of radioactive mannose…
Novel Sortase A Inhibitors to Counteract Gram-Positive Bacterial Biofilms
2019
Sortase A (SrtA) is a membrane enzyme responsible for the covalent anchoring of surface proteins on the cell wall of Gram-positive bacteria. Nowadays it is considered an interesting target for the development of new anti-infective drugs which aim to interfere with important Gram-positive virulence mechanisms. Along the years, we studied the anti-staphylococcal and anti-biofilm activity of some natural and synthetic polyhalogenated pyrrolic compounds, called pyrrolomycins. Some of them were active on Gram-positive pathogens at a μg/mL range of concentration (1.5-0.045 μg/mL) and showed a biofilm inhibition in the range of 50-80%. [1-3] In light of these encouraging results, herein we present…
Novel Stilbene-Based Antileukemic Agents Active in P-Glycoprotein Expressing and Apoptosis-Resistant Acute Leukaemia Cell Lines.
2005
Abstract The stilbene scaffold is a basic element for a number of biologically active natural and synthetic compounds and in accordance with Evans’ definition it can be considered as a privileged structure. One of the most relevant and studied stilbenes is Resveratrol, a phytoalexin present in grapes, endowed with chemopreventive and chemotherapeutic properties and able to induce apoptosis in different cancer cell lines. Since reduced apoptosis has been implicated in the development and progression of malignant tumors and in the occurrence of chemoresistant phenotypes, resveratrol-induced apoptosis might therefore contribute to its antitumor activity. However, resveratrol is a not potent cy…
Endogenous Role of Microsomal Epoxide Hydrolase
2005
The specific activities of microsomal epoxide hydrolase with 16α,17α-epoxyandrosten-3-one (androstene oxide) as substrate were measured in various metabolically important and in various steroidogenic organs of the male and female rat and compared with the activities of 16α,17α-epoxyestratrienol (estroxide) and benzo[a]pyrene 4,5-oxide. Androstene oxide was an exceptionally good substrate. The specific activities differed widely between organs but the ratio of the activities towards these substrates was constant in all organs investigated. The ratios compared to benzo[a]pyrene 4,5-oxide were 2.5 for estroxide, and 8.6 for androstene oxide. The ontogenetic development of specific epoxide hydr…
Rollimembrin, a novel acetogenin inhibitor of mammalian mitochondrial complex I
1997
Abstract Rollimembrin (3), is a new adjacent bis-tetrahydrofuranic acetogenin with a scarce relative configuration, threo/cis/threo/cis/erythro, isolated from Rollinia membranacea seeds. The mechanism of cytotoxic activity, determined by NADH-oxidase experiments, establish that rollimembrin (3) is the most potent inhibitor of mammalian mitochondrial complex I.
Saponin with antibacterial activity from the roots of Albizia adianthifolia
2019
AbstractAn unprecedented saponin is being reported herein together with five known compounds from the methanol extract of the roots of Albizia adianthifolia. The metabolites were obtained over repe...
Saponins as immunoadjuvants and immunostimulants
1999
Saponins are either triterpene or steroid glycosides widely distributed in the plant and animal kingdom and include a large number of biologically active compounds. Most of them have surface-active and cholesterol-binding properties.
Entzündungshemmende wirkstoffe. XI. Ringschlußreaktion an 5-phenyl-2-thiobiuret
1988
Die Umsetzung von 5-Phenyl-2-thiobiuret (1) mil α-Chlorcarbonylverbindungen 2 fuhrt zu den N-Phenyl-N′-(2-thiazolyl)harnstoffen (3). Unter den neuen Verbindungen finden sich besonders die entzundungshemmende, anthelminthische und trichomonazide Wirksamkeit stark ausgepragt. The reaction of 5-phenyl-2-thiobiuret (1) with α-chlorocarbonyl compounds 2 leads to the structure type of N-phenyl-N1-(thiazolyl)urea (3). The new compounds exhibit particularly antiinflammatory, anthelminthic, and trichomonacidal activity.
Structure and properties of pharmacologically active polymers
1975
Although the concept of using pharmacologically active macromolecular compounds as drugs is still regarded with much skepticism for both theoretical and practical reasons, interest in this field has grown in recent years because of the opportunity to take advantage of the specific properties of polymeric materials. For low molecular weight drugs, changes in structure often lead to a loss of specific activity. On the other hand, the properties of macromolecular drugs depend on the structure of the polymer used and this can be varied over a wide range by the incorporation of comonomer units, by the application of polymer-analogous reactions, or by related structural changes. A new model is pr…