Physicochemical Parameters for Structure-Activity-Studies of Substituted Phenyl N-Methylcarbamates

The electronic and hydrophobic substituent parameters of a number of o-, m- and p- substituted phenyl N-methylcarbamates were estimated by measuring the alkaline catalyzed hydrolysis rate constant and 1-octanol/water partition coefficient. Since some o-substituted derivatives are very potent insecticides, emphasis was placed on determining the ortho substituent effects in terms of the existing free-energy related parameters. The information obtained should be useful in structure-activity studies of carbamate insecticides.     

Synthesis of 4-Thiazolone Derivatives Related to Firefly Oxyluciferin

Several 4-thiazolone derivatives were synthesized by condensation of appropriate aryl cyanide and ethyl thioglycolate (or derivative), and factors affecting to the reaction rate are discussed. Keto-enol tautomerization of the 4-thiazolones is briefly discussed.     

An Aspect of Urea Cycle Enzymes in Goat

A large amount of ammonia is produced in the rumen and some portion of the ammonia are absorbed into the portal blood through the rumen mucosa. Accordingly, it seems that ammonia detoxication is more necessary for the ruminant than for the non-ruminant. Activities of the urea cycle enzymes as principal instrument for ammonia detoxication in goat were investigated in this experiment.

The activities of the urea cycle enzymes of goat were found to be very similar to those of rat reported by other authors. The activities of the urea cycle enzymes were affected by the protein level of diet. Administration of magnesium aspartate increased the activities of argininosuccinate synthetase and arginase, and had some effect on the concentrations of citrulline, aspartic acid, and urea in the liver.     

Isomerization and Racemization of Menthols

Menthols were converted to Δ³-menthone enol acetate (VII) via menthones having only one asymmetric carbon atom. It was shown that the optical rotation of menthone enol acetate was proportional to the optical purity of starting menthols. Optical purity of original menthol could, therefore, be determined by optical rotation of menthone enol acetate derived from.     

Application of Axial-haloketone Rule to Lactones

Antifungal activities were examined and compared for some 40 kinds of aliphatic and aromatic aldehydes, alcohols, phenolic compounds, ether compounds and hydrocarbons from essential oils and for some related compounds, using seven fungi.     

Properties of Crystalline α-Glucosidase from Mucor javanicus

Substrate and inhibitor specificities, and transglucosylation action of crystalline α-glucosidase from the mycelia of Mucor javanicus have been investigated. The enzyme hydrolyzed maltose, methyl-α-maltoside, and soluble starch liberating glucose, but little or not phenyl-α-glucoside, methyl-α-glucoside, sucrose, isomaltose, panose and dextran. The enzyme hydrolyzed phenyl-α-maltoside to glucose and phenyl-α-glucoside. The enzyme acted also as a glucosyltransferase when it was incubated with glucosyl donor such as maltose. Maltotriose was the principal transglucosylation product formed from maltose. The enzyme also catalyzed transglucosylation from maltose to riboflavin, pyridoxine, esculin and rutin. Tris and turanose inhibited the enzyme activity, but PCMB and EDTA did not. It is suggested that the enzyme activity is closely related to the histidine residue in the active center, from the inhibition experiments using diazonium-1-H-tetrazole and rose bengal.     

Isolation,Identification and Some Cultural Conditions of Streptomyces Species That Produce Water-insoluble Polyglucan Hydrolase

Cariogenic streptococci produce tenacious water-insoluble polysaccharides from sucrose and these form the structural intercellular matrix of dental plaque. Two Streptomyces species were isolated from soils on agar medium containing the water-insoluble polyglucan as a sole carbon source. They were identified as Streptomyces werraensis (strain F₁) and Streptomyces chartreusis (strain F₂). These strains produced extracellular enzymes which strongly solubilized the polyglucans from various strains of cariogenic streptococci. Strain F₂ produced polyglucanases under rather stationary cultural condition, while F₁ required vigorous aeration. The polyglucanases may provide a useful measure for the prevention and control of dental plaque formation,