A method has been developed for the preparation of protoplasts from both the leaves and tubers of Callilepis laureola, a plant used extensively as a medicament by black people in South Africa. The cellular vacuoles from these protoplasts were isolated and tested for the presence of the nephrotox...

The effects of dithiothreitol (DTT), a sulfhydryl-containing agent and verapamil (VRP), a calcium channel blocker as possible cytoprotectants against the atractyloside-induced toxicity were characterized in rat kidney and liver slices in vitro using multiple markers of toxicity. Precision-cut sl...

Cell suspension cultures were grown from explants of Atractylis gummifera in several culture media. The accumulated biomass differed in the various culture media. The presence of carboxyatractyloside and atractyloside was examined in relation to the different culture media, by means of HPLC. Car...

A selective analytical method based on high-performance liquid chromatography, combined with atmospheric pressure ionisation mass spectrometry, was developed for the detection of atractyloside. The analysis was performed on an Xterra Phenyl column utilising a gradient elution profile and a mobil...

1.1. Amastatin, a specific inhibitor of aminopeptidase A (L-α-aspartyl(l-α-aspartyl(l-α-glutamyl)-peptide hydrolase, EC 3.4.11.7), was linked to an agarose matrix and by this affinity chromatography aminopeptidase A of pig kidneys was purified as a single protein shown by acrylamide gel elect...

The asymmetric Sharpless' dihydroxylation of linalool, citronellyl acetate and nerolidol was investigated. High diastereo-, enantio- and positional selectivity was observed for the first two terpenes. A highly diastereo- and enantioselective synthesis of (3S,6S)-tetrahydro- 2,2,6-trimethyl-...

Both enantiomers of (2R∗,3S∗)-2-allyloxy-3,4,5,6-tetrahydro-2H-pyran-3-ol, a precursor of chiral auxiliary for asymmetric addition of organometallics, and its analog, (2S,3S)-2-ethoxy-3,4,5,6-tetrahydro-2H-pyral-3-ol were prepared by biocatalytic optical resolutions. Lipase-catalyzed enantiosele...

Both enantiomers of 1,4-dideoxy-1,4-iminoarabinitol are specific inhibitors of glucosidases. The synthesis of 1,4-dideoxy-1,4-imino-D-arabinitol involves connecting C2 and C5 of xylose together with nitrogen, whereas the synthesis of 1,4-dideoxy-1.4-imino-L-arabinitol requires C1 and C4 of xylos...

The syntheses of 1,4-dideoxy-1,4-imino-D-lyxitol (3), 1,4-dideoxy-1,4-imino-d-arabinitol (4) and 1,4-dideoxy-1,4-imino-l-arabinitol (5) are reported; (3) is a potent competitive inhibitor of α-galactosidase (green coffee beans) and (4) a competitive inhibitor of α-glucosidase (Brewer's ye...

The effects on plant growth of a sugar analogue, 1,4-dideoxy-1,4-iminoarabinitol (DIA) isolated from Arachniodes standishii, were studied using lucerne seedlings. DIA affected sugar distribution in the seedlings. If seedlings were treated with DIA, the sucrose content increased in cotyledons, an...

The one- and two-dimensional 15N NMR spectra of (E)- and (Z)-2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-diones (1) were measured and analysed and 15N chemical shifts and 1J (15N, 1H) coupling constants were used for characterization of these two compounds from the viewpoint of a...

The synthesis of four new di-n-butyl[bis{dimethyl-2-(3-oxo-5-phenyl(4-subtituted)penten-5-ato)malonates}]tin(IV) 2a–2d is reported. These complexes have been characterized by 1H, 13C, 119Sn NMR, HMQC, HMBC, infrared spectroscopy and mass spectrometry (FAB). Their structures in CDCl3 solution sh...

New derivatives of thiacalix[4]arene, tri- and tetrasubstituted at the lower rim by N-(4-nitrophenyl)acetamide and 1-amidoanthraquinone fragments were synthesized. Their ability for recognition and binding of some anions (F–, Cl–, Br–, I–, MeCO2-, H2PO4-, NO3-) was examined by UV spectroscop...

The molecular and supramolecular structure of the title compound, 3-(tertbutyl)-1-(2-nitrophenyl)-1H-pyrazol-5-amine (2NPz) from the single crystal X-ray diffraction (SC-XRD) and spectroscopic data analysis is reported. The computational analysis of the structure, geometry optimization, vibratio...

Since a fourth MSH sequence, δ-MSH, has been detected in the proopiomelanocortin (POMC) gene of a dogfish and a stingray, members of superorder Squalea (class Chondrichthyes), it is possible that this novel MSH sequence might be a feature common to the POMC genes of all modern sharks and rays. ...

BackgroundHigh levels of blood cholesterol are conventionally linked to an increased risk of developing cardiovascular disease (Grundy, 1986). Here we examine the molecular mode of action of natural products with known cholesterol-lowering activity, such as for example the green tea ingredient e...

We developed a concerted derivatization and concentration method based on dispersive liquid–liquid microextraction (DLLME) for the liquid chromatography (LC) determination of 5-hydroxyindoles (5-HIs; serotonin, 5-hydroxyindole-3-acetic acid, N-acetylserotonin, and 5-hydroxytryptohol). Concerted...

A fluorimetric liquid chromatographic method for the determination of 5-hydroxyindoles based on the benzylamine derivatization process mediated through an online photocatalytic oxidation has been developed. In this study, we used a photocatalytic column comprising tefzel tubing packed with TiO2-...

Rabbit muscle cathepsin H classified as an aminoendopeptidase was purified and its properties were investigated to clarify its contribution to the proteolysis of postmortem muscle. The purification was performed by ammonium sulfate fractionation and successive chromatographies on Sephadex G-75, ...

Ferredoxin-NADP+ reductase (FNR) transfers reducing equivalents between ferredoxin and NADP(H) in the photosynthetic electron transport chains of chloroplasts and cyanobacteria. In most cyanobacteria, FNR is coded by a single petH gene. The structure of FNR in photosynthetic organisms can be con...