The diamagnetic susceptibility of perylene in powdered form has been measured and found to be −(171±1)×10−6 per mole, and from this value the structure of perylene is discussed. A simple method has also been proposed to evaluate the anisotropic part from the mean molecular susceptibilities of aromatic molecules. The present result shows that perylene molecule has two predominant naphthalene nuclei and the central hexagon in this molecule has a spacial structure as compared with the other four.
The author has contrived a new instrument to measure the relative intensity of the ultra-violet radiation using the leuco-base of crystal violet. A quartz glass ampule containing the leuco-base solution is exposed to light and the dyestuff thus produced is determined colorimetrically with a series of a standard solution of crystal violet contained in ampules of the same size. The method of measurement is explained.
The constitution of actiomycin J2 obtained from actinomyces flavus has been studied and idenified to be the dodecyl ester of 5-ketostearic acid by means of hydrolysis of the original substance, followed by the Beckmann rearrangement and hydrolysis of the oxime of 5-ketostearic acid into myristic acid, γ-aminobutyric acid and a small amount of n-tridecyl-amine. Next, the 5-ketostearic acid was synthesized according to two methods, which were concluded respectively by the hydrolysis of condensation products of the type: CH3(CH2)mC(COCH3)(COOC2H5)CO(CH2)nCOOC2H5 and CH3(CH2)n+1CO(COCH3)(COOC2H5)(CH2)n−1COOC2H5, of which the latter gave a considerable yield, while that of the former was very poor owing to the undesired direction of hydrolysis. The condensarion products of 5-ketostearic acid chloride and dodecyl alcohol showed no depression of meltihg point when mixed with actinomycin J2, thus proving the constitution of actinomycin J2 to be the dodecyl ester of 5-ketostearic acid. These experiments were begun since it seemed that actinomycin J2was an antibiotic, but considering the fact that the synthesized specimen demonstrated no such activity, it must be conculded that the original activity was probably due to a minute amount of actinomycin J1 existing as an impurity, and that actinomycin J2 is a mere by-product.
The effects of various inhibitors on nitrate reductase have been investigated and some spectroscopic observations have been made to elucidate the chemical nature of nitrate reductase. From these studies it becomes very probable that cytochrome b of Bac. coli type is identical with nitrate reductase.