Search results for " Thin Layer"

Novel bioactive bromopyrrole alkaloids from the Mediterranean sponge Axinella verrucosa

2005

The Mediterranean sponge Axinella verrucosa has been investigated for its alkaloid composition and has been found to produce a complex mixture of bromopyrrole alkaloids. Along with the previously isolated compounds 5-18, four novel alkaloids of this class, compounds 1-4, have been isolated, and their structures established through spectroscopic methods. Compounds 1-4 were found to display neuroprotective activity against the agonists serotonin and glutamate in vitro.

Levansucrases from Pseudomonas syringae pv. tomato and P. chlororaphis subsp. aurantiaca: Substrate specificity, polymerizing properties and usage of…

2011

Levansucrases of Pseudomonas syringae pv. tomato DC3000 (Lsc3) and Pseudomonas chlororaphis subsp. aurantiaca (also Pseudomonas aurantiaca) (LscA) have 73% identity of protein sequences, similar substrate specificity and kinetic properties. Both enzymes produce levan and fructooligosaccharides (FOS) of varied length from sucrose, raffinose and sugar beet molasses. A novel high-throughput chip-based nanoelectrospray mass spectrometric method was applied to screen alternative fructosyl acceptors for levansucrases. Lsc3 and LscA could both transfructosylate D-xylose, D-fucose, L- and D-arabinose, D-ribose, D-sorbitol, xylitol, xylobiose, D-mannitol, D-galacturonic acid and methyl-α-D-glucopyra…

Staining of immunoblots by immunochromatography.

1994

Three New Triterpene Saponins from Two Species of Carpolobia

2002

Three new acetylated triterpene saponins 1-3 were isolated from the roots of Carpolobia alba and C. lutea. Their structures were established mainly by 2D NMR techniques as 3-O-beta-D-glucopyranosylpresenegenin-28-O-beta-D-galactopyranosyl-(1-->4)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-(3,4-di-O-acetyl)-beta-D-fucopyranosyl ester, 3-O-beta-D-glucopyranosylpresenegenin-28-O-beta-D-galactopyranosyl-(1-->4)-[alpha-L-arabinopyranosyl-(1-->3)]-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-(3,4-di-O-acetyl)-beta-D-fucopyranosyl ester, and 3-O-beta-D-glucopyranosylpresenegenin-28-O-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl…

Assessment of the antioxidant and antibacterial activities of different olive processing wastewaters.

2017

Olive processing wastewaters (OPW), namely olive mill wastewater (OMW) and table-olive wastewaters (TOW) were evaluated for their antibacterial activity against five Gram-positive and two Gram-negative bacteria using the standard disc diffusion and thin layer chromatography (TLC)-bioautography assays. Disc diffusion screening and bioautography of OMW were compared to the phenolic extracts of table-olive brines. Positive activity against S. aureus was demonstrated. The optimization of chromatographic separation revealed that hexane/acetone in the ratio of 4:6 was the most effective for phenolic compounds separation. A HPLC-MS analysis was performed showing that only two compounds, hydroxytyr…

Inhibition of giant cell formation by compound 48/80 after infection with herpesvirus hominis

1974

Choline kinase has been found to be a soluble enzyme with a molecular weight of 105,000 in the cytoplasm of primary rabbit kidney cells. It has been purified 150-fold. It was investigated whether the inhibiting effect of Cpd 48/80 on virus-induced giant cell formation is due to interference with this enzyme. Cpd 48/80-dimer was shown to inhibit the choline kinase activityin vitro without a concomitant inhibition of giant cell formation. Likewise, another competitive inhibitor of choline kinase, purinyl-6-histamine, does not prevent giant cell formation. This finding suggests that there is no correlation between choline kinase activity and giant cell formation.

Selective labelling of melittin with a fluorescent dansylcadaverine probe using guinea-pig liver transglutaminase

1991

Abstract Melittin, a C-terminal peptide, incorporated the fluorescent probe monodansylcadaverine (DNC) when catalysed by guinea-pig liver transglutaminase and Ca2+, as determined by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A 1:1 adduct DNC-melittin was identified in which a single glutamine residue out of two, i.e. Gln25, acts as acyl donor. Incubation of melittin with transglutaminase in the absence of DNC originated high molecular mass complexes indicative that the peptide lysine residue can act as an acyl acceptor. The DNC-melittin was about 3 times more active in the lysis of red cell membranes than native melittin. Fluorescence study of the lab…

Characterization of Membrane-Bound Cyclic Nucleotide Phosphodiesterases from Bovine Aortic Smooth Muscle

1992

This study reports the isolation and characterization of cyclic nucleotide phosphodiesterases (PDEs) associated with membrane fraction in comparison to cytosolic forms from bovine aorta. DEAE-Sephacel chromatography of a solubilized membrane fraction from a homogenate, prepared under isotonic conditions in the presence of protease inhibitors, yielded one major peak of PDE activity that specifically hydrolyzed cAMP and was not stimulated by calmodulin: It appeared to contain two subtypes of PDE. The first subtype belonged to the cyclic GMP (cGMP)-inhibited PDE family, (PDE III): It had an apparent Km value of 0.4 microM and was potently inhibited by cGMP, LY186126, and cilostamide. The secon…

New reagent for the detection of sesquiterpene lactones by thin-layer chromatography.

1984

Use of two-dimensional thin-layer chromatography for the components study of poly(adenosine diphosphate ribose)

1990

Two-dimensional thin-layer chromatography on cellulose plates has been used for separating and quantifying the three adenosine derivatives: AMP, phosphoribosyl AMP (PRAMP), and (PR)2AMP obtained by venom phosphodiesterase digestion of poly(ADP-ribose). In vitro synthesized polymer, up to 300 derivatives in length were studied. Some parameters of the complexity of poly(ADP-ribose) could be deduced from our results: (i) The first branching point appears in fragments of approximately 21 derivatives in length. (ii) The branching points are located at regular distances of approximately 41 derivatives from each other.