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The present article aims at giving some information concerning the mode of action of three dithiocarbamates: ferric dimethyldithiocarbamate (Ferbam), zinc dimethyldithiocarbomate (Ziram) and tetramethylthiuram disulfide (Thiram). These inhibitors were tested on the respiratory activity of the Myxomycete: Physarum polycephalum. Its development is strongly inhibited at 285 mg/l. With such concentration, respiration measurements confirmed total inhibition of O2 uptake. After isolation of the mitochondria, the tests showed that there may be an inhibition of the succinic oxidase activity of this particulate fraction, at 28.5 mg/l of Thiram. Heavy concentration of reduced glutathione (1.4%) reversed partially this inhibition. This seems to prove that succinic dehydrogenase is a typical SH-type enzyme. [ABSTRACT FROM AUTHOR]

The effect of different concentrations of sodium dimethyldithiocarbamate (Na-DMDT) and tetramethylthiuram disulphide (TMTD) on photosynthesis of Enteromorpha linza was investigated. The rate of photosynthesis was measured manometrically in medium of pH 8, with a sea water base, and containing the buffer tris-(hydroxymethyl)-aminometane. The effect of the substances on the endogenous respiration in the dark was also investigated. There was no effect on respiration, while photosynthesis was inhibited. Ca. 90% inhibition was obtained with 6 μM TMTD or 90 μM Na-DMDT. Maximum inhibition occurred only 10–15 minutes after the addition of one of the substances. Possible mechanisms for the effects are discussed. [ABSTRACT FROM AUTHOR]

This article presents analytical methods for dithiocarbamyl compounds. A number of methods for determining or assaying dithiocarbamyl compounds have been proposed. To the first can be assigned those methods that use titration techniques. In a second group can be placed the methods which make use of ability of many of these compounds to give off carbon disulfide after acidification. To the third method, it is natural to assign the spectrophotometric methods. Spectra in the UV and visible region have been used to determine various dithiocarbamates.

This article presents observations regarding the effect of dithiocarbamyl compounds on enzyme reactions. In the present work, only a few experiments have been done with cell-free homogenates, and none with purified enzyme systems. The first enzyme activity that was studied in homogenized cells was the succinic oxidase activity. The Warburg technique was employed. The particulate fraction was used, suspended in a phosphate buffer of pH 0.3. To see whether the inhibition occurred in the cytochrome oxidase system or the succinic dehydrogenase system, another experiment was carried out in which methylene blue was added.

This article focuses on the effect of dithiocarbamyl compounds on anabolic processes. These experiments were carried out to study the effect of the concentration of the initial inoculum of yeast on the growth rate and the action curve for sodium-dimethyldithiocarbamates (Na-DMDT). It is seen that increase in turbidity only starts after a lag period of about 2 hours. After a while, the volume of the individual cells perhaps also starts to increase. It has been seen that in flasks where Na-DMDT has been added, cell division has stopped immediately, while the increase in turbidity has continued at a slowly declining rate.

This article focuses on the effect of dithiocarbamyl compounds on oxidative reactions in intact and resting yeast cells. Various pathways have been proposed for the reaction sequence leading to the complete oxidation of glucose to carbon dioxide and water in yeast cells. Whereas the glycolytic route to pyruvic acid for some time has been assumed to be the sole passage through the anaerobic stages, new investigations stress the importance of the so-called Dickens scheme or oxidative shunt, which by passing through phosphogluconic acid, ribulose-5-phosphate and glyceraldehyde-3-phosphate, leads to pyruvic acid.

This article presents studies on the stability of the dithiocarbamyl compounds, and their behaviour in biological systems. It is well known that dithiocarbamates hydrolyze to give carbon disulfide and amino-salt in acid solution. In an unbuffered system, the hydrolysis of these compounds will induce a shift towards higher pH values, and this will help in stabilizing a moderately concentrated solution. In biological investigations and particularly in growth experiments, it is however, virtually impossible not to introduce heavy metals to some extent and therefore the free dithiocarbamate ion concentration will also depend on the concentration of these.

This article investigates the uptake of dithiocarbamyl compounds by yeast suspensions. After having been shaken overnight, the yeast was twice washed by centrifugation and resuspension in thiosulphate buffer. It is seen that in the yeast suspension, the absorption maximum is lying closely as it does in water. Under the conditions in this experiment, the cupric atom in dimethyldithocarbamate complex is still surrounded by polar molecules to a large degree. This does not necessarily rule out the possibility of an adsorption of the complex at a nonpolar phase-border by the lipophilic dimethyl groups in either end of the molecule.

This article reports on the effectiveness of metham-sodium (32 per cent formulation of anhydrous sodium methyl dithiocarbamate in water solution with stabilizer) injected and drenched into the soil was compared with D-D (dichloropropane-dichloropropene mixture) injected in replicated randomized plots for the control of potato root eelworm in glasshouse soils at two centers for two and three years. The D-D and untreated control plots were drenched with formaldehyde. With all treatments the final cyst densities were higher than the initial densities but numbers of viable larvae were reduced. Tomato plants grew better on treated plots but the greater yield, height, truss production and vigor could not be related entirely to the loll of potato root eelworm.

The aim of this study is to examine the performances of copper and dithiocarbamate fungicides from the dual standpoint of blight control and phytotoxicity effects under different conditions of season and locality. The study also seeks to ascertain over a period of years, the number of seasons in which blight control was economic in the important potato-growing area which centers upon Yeovil in South Somerset. Series of spraying trials with similar objectives to the latter have already been reported from other parts of England.

This article provides information on comparative trials of copper dithiocarbamate and organo-tin fungicides for potato blight control in Lincolnshire, England from 1958-1961. In trials at three centers in 1958, three spray applications proved inadequate for the control of blight but the gain from spraying was significantly better with zineb than with copper oxychloride. With 6 to 8 applications at weekly intervals, in the three following years, copper, zineb, maneb and triphenyltin acetate gave about equal control of the disease on the foliage, but both in the dry, hot season 1959, when the blight attack was very late, and also in the wet season 1960, copper oxychloride gave a lower gain in yield from spraying than the other three fungicides at a number of the centers, probably due to phytotoxic effects .

This article focuses on the effect of the dithiocarbamyl compounds on the Pasteur Mechanism in intact cells. There is much biochemical evidence supporting the assumption that the levels of inorganic and energy-rich phosphate act as regulators of the reaction rate of energy-generating processes in the cell. The results show conclusively that the dithiocarbamyl compounds have no effect at all on the phosphorylative couplings and the energy transfer in intact cells at concentrations which cause growth inhibition.

This article describes a series of pot experiments on the effect of sodium methyl dithiocarbamate on potato root eelworm. Pots filled with compost, containing loam, steam-sterilized six months, were divided into two groups one of which was inoculated with potato root eelworm cysts. The other group was retained to assess the effects of the chemical in the absence of eelworm. Each group was applied with the chemical by injection at three equally spaced points. The researchers have found that growth of tomatoes was not affected at the lower levels of infestation and was improved at the higher level as a result of treatment. Moreover, the chemical did not affect growth in the absence of a pathogen.