No abstract

The fate in the rabbit of the following compounds has been investigated: benzohydrazide and its p-chloro, p-methyl and nand p-hydroxy derivatives; 1-acetyl-2-mand-p-hydroxybenxoylhydrazines and their anhydrides; 2-mand-phydroxyphenyl-5-methyl-1-oxa-3:4-diazoles. 2. Benzohydrazide, p-chlorobenzohydrazide and p-methylbenzohydrazide were lethal to rabbits in oral doses of just over 100 mg./kg. and were metabolized to the corresponding hippuric acids, which were isolated from the urine. Hydroxylation of the benzene ring and acetylation of the hydrazide group were not detected. 3. p-Hydroxybenzohydrazide and its acetyl derivative and I-acetyl-2-p-hydroxybenzoylhydrazinewere relativelynon-toxic andwere metabolized by direct conjugation with glucuronic and sulphuric acids. 4. m-Hydroxybenzohydrazide was intermediate in toxicity between benzohydrazide and phydroxybenzohydrazide, and was metabolized mainly by direct conjugation but partly by hydrolysis to m-hydroxybenzoic acid. 5. 2-m-and-p-Hydroxyphenyl-5-methyl-oxa-3:4-diazoles were relatively non-toxic and were metabolized by direct conjugation mainly with glucuronic acid. 6. It is suggested that the toxicity of benzo-hydrazide and its p-chloro and p-methyl derivatives is due to release of hydrazine in vivo.

No abstract

SUMMARY: A series of four factorial experiments with culture media was carried out dealing with (1) the action of individual salts and their interactions in the medium, (2) the relation of the nitrogen source to the action of the salts, (3) the effect of the ratio of the carbon source and (4) the proportionate influence of the salts in the medium. Statistical analysis of the results has shown (a) the composition of the culture medium which produces optimal growth under given conditions, (b) that a suitable balance of salts in the medium, while conducive to good growth, is not of over-riding importance to this fungus, and (c) that ammonium nitrate serves as the key nutrient in the balance of salts which produces optimal growth measured as milligrams of dry weight.The real study of the nutrition of fungi probably began when Raulin introduced his defined medium in 1869. Since that time there have been numerous accounts of, and references to, fungal nutrition, but there is a lack of statistical investigations of the food requirements of fungi which are complete from one aspect of nutrition. Such investigations, which of necessity cover a limited field, give a reliable picture of the behaviour or response of the fungi concerned expressed in some arbitrary but standard terms such as dry weight. The results are of value because they can serve as the basis for systematic comparisons under fixed and reproducible conditions of growth and for metabolic investigations which are becoming of increasing importance in the study of fungal physiology, and they also have an industrial application. As early as 1922, Young & Bennett, using Mamosporium sarcineforrne, Fusarium oxysporum and Phoma apicola with the salts calcium nitrate, acid potassium phosphate and magnesium sulphate a t different molar concentrations, found that a correct balance of the mineral elements was essential for maximum growth, but that this behaviour varied according to the species of fungus used as test organism. Other workers have also obtained results indicative of a similar conclusion, until Talley & Blank (1941) gave the results of their careful statistical analysis of the nutritional requirements of Phymatotrichum omniworum, the causal organism of the root rot disease of cotton and other plants. These results showed that the absolute amount of certain essential metabolites was not so important as the balance between them. While the balance of salts may affect the overall metabolism of the fungus there are also indications that it may affect the synthesis of individual compounds such as penicillin. For instance, Pratt (1945) found that variations in the concentrations of KH,PO, ,