The isotopic exchange of35S between thiosulfate/sulfite and tetrathionate/thiosulfate is examined. The kinetic data are determined. In both cases the
reactions are of second order. As the isotopic exchange between tetrathionate/thiosulfate is very fast, these reaction components
are used in high dilution. Furthermore, the extent of exchange during the separation is determined.
Outer and inner35S-labelled S3O
are prepared and then hydrolyzed at different temperatures. The separation of the reaction mixture is made by high-voltage
paper ionophoresis. The amount of activity is determined directly on the paper by liquid scintillation. The ratios of activity
of the reaction products are compared with those calculated on the basis of three different reaction mechanisms. All experimental
results agree very well with the authors' proposed reaction mechanism via the unsymmetrical intermediate−O3S−SOH. The influence of the isotope exchange between S2O
on the ratio of activity is examined at different temperatures. Attempts have been made also to capture the SO
which orginates from the first step of the S4O
Degradation by silver permits determination of the distribution of activity inside the labelled molecule for thiosulfate and
for the polythionates. When single salts are present, the reactions can be carried out either in solution or on the pherogram.
In comparison, for mixtures of sulfur anions, it is necessary to perform previously a high voltage inonophoretic separation.
The cutout zone of a definite anion is put on a new pherogram and the degradation by silver is carried out. The results correspond
within the accuracy of measurement to the theoretical values.
The isotopic exchange of sulfur-35 between trithionate/sulfit and tetrathionate/pentathionate is examined. High voltage paper
ionophoresis is applied for the separation of the reaction mixture. The amount of activity of the reaction products is determined
at different times. This enables to calculate the kinetical data of those exchange systems.
It is shown in the present work that the labelling of steroids in ring D is suitable for the production of stable compounds.
Two syntheses are described. The final products represent the tritium labelled forms of two pharmacologically important 4,9-dienones
with high radiochemical purity. Unfortunately, these dienones are very sensitive to self-radiolysis. They must be stored as
diluted solutions at low temperature.
Authors:I. J. Agudelo, H. Bach, R. A. Ricco, and M. L. Wagner
Chañar (Geoffroea decorticans- Fabaceae) is a tree from South America that is normally infected with galls originated by insects. One of its parasites is Allodiplosis crassa (Cecidomyiidae, Diptera) which produces globular galls with sticky prolongations. Since this plant has medicinal uses in Argentina, its infestation could alter the quality of the plant drug. The surface of insect-induced galls usually contains defensive features such as trichomes, increased hardness and an increase in the content of polyphenolic compounds. The objective of this research is to assess the structural and histochemical features of the gall and to compare the content of polyphenolic metabolites in the gall, in the healthy leaf and in lignified stems of G. decorticans. The methanolic extract from the galls showed the highest amount of polyphenolic and proanthocyanidins and the lowest amount of hydroxycinnamic derivatives and flavonoids compared to the methanolic extract of the leaves. The photographs taken from the external surface of the gall showed that some prolongations have heads. The histochemical analysis showed that the prolongations have a high amount of proanthocyanidins and flavonoids; and that the heads are reactive to Sudan III. These phytochemical and histological characteristics may have a defensive role against harmful fungi and parasites that attack the larvae of the A. crassa. The results of this study show the presence of defensive features in an insect-induced gall of a medicinal plant with potential implications in the pharmacological activity of this species. This is the first report of a histochemical and phytochemical study in G. corticans galls.
Authors:Tibor Gaál, L. Wágner, F. Husvéth, H. A. Manilla, P. Vajdovich, N. Balogh, I. Lóth, and Katalin Németh S.
The influence of fish oil (highly unsaturated) and beef tallow (highly saturated) with vitamin E (100 IU/kg) supplementation on the antioxidant status of broiler chicken cockerels was investigated. Chicks were fed a control diet with no added fat, 40 g/kg each of fish oil and beef tallow diets, respectively, from 11 to 42 days of age. Tocopherol concentration and the rate of lipid peroxidation, thiobarbituric acid reactive substance (TBARS) in liver, fatty acid composition of the liver lipids, blood serum total antioxidant status (TAS), and reduced glutathione (GSH) content were determined. Vitamin E supplementation of the diet increased liver ?-tocopherol content in chicks regardless of the type of dietary fat. Fish oil diet resulted in higher liver TBARS value while beef tallow diet showed lower values compared to the control diet. Vitamin E supplementation reduced liver TBARS as well as serum GSH, and raised serum TAS for all diets. Serum GSH was the same for vitamin E supplemented diets regardless of the fat supplement. Fish oil diets resulted in a significant increase in hepatic lipid n-3 PUFA content. A significant positive correlation was found between liver TBARS and n-3 PUFA content. No relationships were established, however, between liver TBARS and n-6 PUFA or saturated fatty acids. The results suggest that feeding oils rich in n-3 PUFA increases tissue concentration of these fatty acids, consequently increasing tissue lipid peroxidation and reducing the antioxidative status of broiler chickens. Supplementing high levels of vitamin E with such oils may increase tissue oxidative stability. Serum TAS or GSH may be used as a measure of antioxidative status in chickens.
Authors:M. Krivopustov, A. Pavliouk, A. Kovalenko, I. Mariin, A. Elishev, J. Adam, A. Kovalik, Yu. Batusov, V. Kalinnikov, V. Brudanin, P. Chaloun, V. Tsoupko-Sitnikov, A. Solnyshkin, V. Stegailov, Sh. Gerbish, O. Svoboda, Z. Dubnicka, M. Kala, M. Kloc, A. Krasa, A. Kugler, M. Majerle, V. Wagner, R. Brandt, W. Westmeier, H. Robotham, K. Siemon, M. Bielewicz, S. Kilim, M. Szuta, E. Strugalska-Gola, A. Wojeciechowski, S. Hashemi-Nezhad, M. Manolopoulou, M. Fragopolou, S. Stoulos, M. Zamani-Valasiadou, S. Jokic, K. Katovsky, O. Schastny, I. Zhuk, A. Potapenko, A. Safronova, Zh. Lukashevich, V. Voronko, V. Sotnikov, V. Sidorenko, W. Ensinger, H. Severin, S. Batsev, L. Kostov, Kh. Protokhristov, Ch. Stoyanov, O. Yordanov, P. Zhivkov, A. Kumar, M. Sharma, A. Khilmanovich, B. Marcinkevich, S. Korneev, Ts. Damdinsuren, Ts. Togoo, and H. Kumawat
An extended U/Pb-assembly was irradiated with an extracted beam of 2.52 GeV deuterons from the Nuclotron accelerator of the
Laboratory of High Energies within the JINR in Dubna, Russia. The lay-out of this experiment and first results are reported.
The Pb-target (diameter 8.4 cm, length 45.6 cm) is surrounded by a natU-blanket (206.4 kg) and used for transmutation studies of hermetically sealed radioactive samples of 129I, 237Np, 238Pu and 239Pu. Estimates of transmutation rates were obtained as result of measurements of gamma-activities of the samples. Information
about the spatial and energy distribution of neutrons in the volume of the lead target and the uranium blanket was obtained
with sets of activation threshold detectors (Al, Y and Au) and solid state nuclear track detectors (SSNTD). An electronic
3He neutron detector was tested on-line. A comparison of experimental data with theoretical model calculations using the MCNPX
program was performed yielding satisfactory results.