In order to further elucidate the mechanism of metabolic difference between sumithion and methylparathion, distribution of sumithion and methylparathion into several tissues, activation, that is, conversion into more toxic oxygen analogs, and degradation into non-toxic compounds were examined in vivo following the intravenous administration of the phosphorothioates to Guinea pigs and white rats. Sumioxon and methylparaoxon were detected in all tissues tested, among which lung and liver were richest in them. More sumioxon than methylparaoxon was found. here organophosphorus compounds were found to be decomposed to non-toxic desmethyl compounds and dimethyl phosphorothioic acid mainly in liver and kidney. From these results it seems improbable that the lower toxicity of sumithion than that of methylparathion results from the different in their rate of metabolism.

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As reported previously¹⁾, sumithion and sumioxon inhibit brain cholinesterase activity of mammals less potently in vivo than methylparathion and methylparaoxon respectively. Phosphorus³² content and inhibition of cholinesterase in Guinea pig brain were investigated in vivo after the intravenous administration of phosphorus³² labeled phosphorothioates and their oxygen analoges, in order to clarify if any relationships be observed between phosphorus content and inhibition. Although content of phosphorus derived from sumithion was not significantly different from that obtained from methylparathion, reduction of cholinesterase activity by methylparathion was strikingly larger than that by sumithion. On the other hand, phosphorus derived from sumioxon was found to penetrate into Guinea pig brain less than methylparaoxon phosphorus, and as the result the former hindered the enzyme activity less effectively. From these results, the mechanism of lower toxicity of sumithion toward mammals was presumed.

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A new inhibitor of plant growth, named rosellinic acid, C₁₁H₁₀O₅, m. p. 206_??_208°C, has been isolated from the culture filtrate of Rosellinia necatrix Berlese. Rosellinic acid has one C-methyl, one phenolic hydroxyl and one aryl carboxylic acid group. Fusion with alkali gave 4, 5-dihydroxyiso-phthalic acid, and the results of physical and chemical tests on the rosellinic acid led to the conclusion that the formula of 6-carboxy-8-hydroxy-2-methylchromanone seems the most possible structure.

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The fractions obtained from the ether soluble part of rice vinegar were separated by means of cellulose column and of Amberlite XE-64 ion exchange resin._??_he following compounds were identified: p-hydroxyphenylethanol, p-hydroxyphenylacetic acid, p-hydroxyphenyllactic acid, p-hydroxybenzoic acid and phenyllactic acid.

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An enzyme “amine transaminase”, which catalyzed transamination between amines and α-keto acids, was found to occur in certain fermentative bacteria, such as Escherichia coli and Aerobacter aero-genes. Using a partially purified enzyme preparation obtained from cell extract of E. coli, some properties of the enzyme were investigated. α-Ketoglutaric acid appeared to be the most efficient amino acceptor and substitution of α-ketoglutaric acid by other α-keto acid resulted in much lower activity. Putrescine, cadaverine and hexamethylenediamine were found to be active as amino donors, but the other monoamines, diamines and polyamines were inert. Treatment of the enzyme with acid ammonium sulfate resolved the enzyme into apo-and coenzyme. The apoenzyme was well reactivated by pyridoxal phosphate as well as pyridoxamine phosphate. Physiological role of the amine transaminase was suggested in relation to the metabolism of amines in bacterial cells.

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A new amino acid, 2-pyrrolidine acetic acid and 1-pipecolic acid were isolated from cured tobacco leaves. The former structure was confirmed by comparison with synthetic compound.

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Synthesis of (±)-trans-chrysanthemic acid from (±)-trans-caronic acid via ester of (±)-1'-hydroxy-dihydro-trans-chrysanthemic acid by the dehydration with p-toluene-sulfonic acid was attempted. However, the attempt was found to be unsuccessful giving a compound believed to be methyl methyl 2, 6 dimethylhepta-3.6-diene-5-carboxylate upon dehydration.
A cleavage upon cyclopropane ring was confirmed by deriving the acid obtained by the hydrolysis of the above ester to already known 2, 6-dimethyl-heptane-5-carboxylic acid.
Analogous mode of dehydration and cleavage upon the ester of (±)-2, 2-dimethyl-3-trans-hydro-xylbenzyl-cyclopropane-l-carboxylic acid was also observed to give 1-phenyl-4-methyl-penta-l, 3-diene-3-carboxylic acid. On the other hand, (±)-trans-caronic acid being derived to (±)-1'-oxo-2'-hyd-roxy-dihydro-trans-chrysanthemic acid, the synthesis of (±)-trans-chrysanthemic acid from (±)-trans-caronic acid became possible using (±)-1'-oxo-2'-hydroxy-dihydro-trans-chrysanthemic acid as a relay substance.

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A photodynamic agent was isolated from the liver of abalone, Haliotis discus hannai, and identified as pyropheophorbide a. This red fluorescent pigment was proved to induce photosensitization both in rats and cats by oral administration, and recognized as the sole photodynamic pigment in the liver.
The periodical examination on several kinds of herbivorous gastropods indicated that the liver becomes toxic only in spring.

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Zygosaccharomyces soja mutant obtained from cycloheximide treatment accumulated several kinds of nucleotides together with riboflavin in the minimal glucose salt medium. Accumulation of nucleotides took place in parallel with the propagation of the microorganism after inoculation. That the nucleotides accumulated were identical to 5'-CMP, 5'-AMP, 5'-UMP, 5'-GMP and UDP, ADP, GDP respectively was verified using chemical and enzymic procedures. It was assumed that the excretion of these nucleotides was mainly carried out by the action of polynucleotide phosphorylase.
It was also surmised that the excretion of AMP at the early stage of incubation meant leakage from de novo synthesis.

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In preceding paper¹⁾, it was reported that Zygosaccharomyces soja mutant accumulated several kinds of 5'-nucleotides in the culture fluid. Polynucleotide phosphorylase as the enzyme related to excretion was also assumed. For the purpose to clarify the dependence of nucleotide excretion upon polynucleotide phosphorylase, studies were made to the excretion of 5'-nucleotide from resting intact cells of Z. soja mutant. In an alkaline buffered solution (pH 9.0), nucleotide excretion was stimulated markedly by the addition of orthophosphate. After analysis of extracellularly accumulated nucleotide during incubation, four kinds of 5'-nucleotides (CMP, AMP, UMP, GMP) were isolated as the main products, indicating the responsibility of polynucleotide phosphorylase to the breakdown of endogenous RNA. Discussions were presented to illustrate the failure in detection of nuclcoside diphosphate.

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It was reported in preceding paper, ²⁾ that several kinds of 5'-nucleotides were excreted by incubating resting intact cells of Zygosaccharomyces soja mutant in an alkaline medium in the presence of orthophosphate. That the presence of orthophosphate stimulated markedly the excretion of 5'-nucleo-tides suggested the responsibility of polynucleotide phosphorylase on autodegradation of endogenous RNA. Further verification to the responsibility of the enzyme on authodegradation of RNA was demonstrated in this report using cell-free extract of Z. soja mutant. Incubating the cell-free dialyzed preparation in an alkaline buffered medium, formation of several kinds of nucleotide was verified. The resemblance of the composition of excreted nucleotides to that of RNA degradation product was also observed. That orthophosphate and magnesium ions were verified to be essential for autodegradation of endogenous RNA indicated that polynucleotide phosphorylase mainly played a role in the autodegradation. The finding that nucleoside diphosphate could not be obtained as the degradation product of endogenous RNA by polynucleotide phosphorylase illustrated that the breakdown of nucleoside diphosphate formed was rapidly brought about by the action of pyrophosphatase present in cell-free preparation.

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From the findings of the feeding experiments of d- and l-nicotine-¹⁴CH₃ and d-nicotine to the excised tobacco leaves, it was demonstrated that demethylation of nicotine was stereospecific for the d-form in tobacco leaves. Such preferential demethylation to the enantiomer was also observed with N-methylanabasine and 1-(3'-pyridyl)-l-methylaminoethane which are analogous compounds to nicotine.

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