Effect of ginseng saponins on the survival of cerebral cortex neurons in cell cultures

The effects of nerve growth factor (NGF) and saponins isolated from Panax ginseng C.A. Mayer on the survival of chick and rat embryonic cerebral cortex neurons were examined. Ginsenoside Rg1 (GRg1) exerted a survival-promoting effect on both chick and rat cerebral cortex neurons in cell cultures. Ginsenoside Rb1 (GRb1) also had an effect in the rat and displayed some influence in the chick. NGF alone exerted no effect on both neurons, although it did potentiate the GRb1 effect on chick embryonic cerebral cortex neurons, but did not alter the GRb1 effect on rat embryonic cerebral cortex neurons. NGF did not alter the survival-promoting effect of GRg1 on either chick or rat embryonic cerebral cortex neurons. The other saponins alone or with NGF exerted no effect on the survival of cerebral cortex neurons in either the chick or rat.     

Precolumn derivatization of nucleotides based on fluorescent carbamate formation of the sugar moieties in high-performance liquid chromatography.

The fluorescence derivatization of nucleotides with 2-(5-chlorocarbonyl-2-oxazolyl)-5,6-methylenedioxybenzo++ furan in the presence of sodium azide and the separation of the derivatives by high-performance liquid chromatography are described. The reagent reacts with 5'-terminal hydroxyl groups of nucleotides to produce the corresponding fluorescent carbamates. The derivatives of mono- and oligonucleotides are separated by chromatography on a reversed phase column (TSKgel ODS-80TM) and the derivatives of octa- and deca-nucleotides on a size exclusion column (TSKgel G3000SWXL). The detection limits (signal-to-noise ratio = 3) are 0.8-6.0 pmol on column. 5'Phosphorylated nucleotide also gives a fluorescent derivative after alkaline phosphatase-mediated dephosphorylation.     

Precipitation of some nonionic polymers by octylammonium thiocyanate

The effects of various alkylammonium thiocyanates (ethyl, butyl, hexyl, and octyl) on aqueous solutions of polyvinylpyrrolidone (PVP) and poly(vinyl alcohol–acetate) copolymer (PVA-Ac) were studied and compared with the effects caused by the respective chlorides. Whereas the PVP solution was hardly affected by the chlorides, it was precipitated by n-octylammonium thiocyanate (OASCN) at dilute concentrations and dissolved at higher concentrations. On taking the effects of ammonium chloride and thiocyanate on the solubility of PVA-Ac as references, with increasing of alkyl chain length, alkylammonium chlorides raised the polymer solubility steadily; on the contrary, the thiocyanates at dilute concentrations, except for ethylammonium thiocyanate, lowered it, and OASCN at dilute concentrations, except for ethylammonium thiocyanate, lowered it, and OASCN at dilute concentrations was a particularly strong salting-out agent. The amount of binding of OASCN to the polymers in the precipitated systems was measured. The precipitation was attributed to ion-pair binding of OASCN to the polymers, and the mechanism was discussed in terms of the interaction between the water structure-breaking SCN^? and the water structure-making hydrophobic groups.     

On the use of methyl substituted poly(vinylnaphthalene) as a reversible singlet oxygen carrier

Poly(1,4-dimethyl-6-vinylnaphthalene) and poly(1,2,4-trimethyl-6-vinylnaphthalene) react with singlet oxygen to give corresponding endoperoxide polymers which on warming generate singlet oxygen efficiently. Singlet oxygenations by the use of these polymers have been described.     

Relative sensitivity factors in direct current glow discharge mass spectrometry using Kr and Xe gas — Estimation of the role of Penning ionization

Relative sensitivity factors (RSF) (Fe=1) were determined for steel, aluminium and copper standard samples by direct current glow discharge mass spectrometry using Kr and Xe as discharge gas. In general, the RSF values in Kr and Xe were higher than in Ar; however for S and P in Kr gas and P, As and Se in Xe gas they were considerably lower. This decrease is related to the relative importance of the Penning ionization process in overall ionization of the sputtered species. The results showed the percentage of Penning ionization to account for 75.6–82.0% for Se, As and P and 64.2% for S.