2, 6-Dimethyl-hepta-2, 4, 6-triene-5-carboxylic acid was derived from methyl dihydroxydihydrochrysanthemate by means of dehydration in the presence of p-toluene-sulfonic acid and following hydrolysis. The completely identical acid was also obtained by treating ethyl cis and trans-chrysanthemates with aqueous hypochlorous acid and following hydrolysis. The skeletal structure of the said acid was confirmed by deriving it to already known 2, 6-dimethylheptane-5-carboamides. Novel cleavages on cyclopropane ring are now proposed.

View full abstract

The acid melting at 143°C, which was separated from the oxidation product of (±) chrysanthemic acid (I) with potassium permanganate and had been believed to be an isomer of dihydroxy-dihydrochrysanthemic acid, was confirmed to be (±)-2, 2-dimethyl-3 (1'-oxo-2'-hydroxy-2'-methyl) propyl-1, 3-trans-cyclopropane-1-carboxylic acid (II). Optically active acid was obtained from (±)-trans-chrysanthemic acid, and the several chemical behaviours of these acids were described.

View full abstract

Methyl (-)-2, 2-dimethyl-3-(1′-oxo-2′-hydroxy-2′-methyl) propyl-1, 3-trans-cyclopropane-1-carboxylate was treated with potassium tert.-butylate and gave tert.-butyl ester of the racemic acid. Transesterification and simultaneous racemization of the two asymmetric carbon atoms on cyclopropane ring were observed.
From the racemic acid, (±)-trans-chrysanthemic acid was derived by means of Huang Minion modification using hydrazine hydrate and diethyleneglycol. Combination of these reactions makes it possible to derive racemic trans-chrysanthemic acid from optically active one.

View full abstract

In order to understand the mechanism of the enzymic oxidation of epigallocatechin, ethyl gallate was taken up as a model substrate on account of its close structural similarity to the vic-trihydroxyphenyl group, which indeed is supposed to be attacked by oxidase, when epigallocatechin is oxidized enzymically. By the action of tea or apple oxidase at pH 5.5, it gave a characteristic polyphenolic substance, which was obtained in prisms, C₁₈H₁₈O₁₀-2H₂0, and proved to be diethyl 4, 4', 5, 5', 6, 6'-hexahydroxydiphenate, as the product was converted into ellagic acid by hydrolysis of ester linkage and then lactone formation.

View full abstract

2-Ethylthio-1-(4-hydroxy-3-methoxyphenyl)-propanone-(l)(I) which has been previously isolated from mercaptolysis oil of pine ethanol lignin was also obtained from mercaptolysis oil of spruce wood. 1-Ethylthio-1-(4-hydroxy-3-methoxyphenyl)-propanone-(2)(II), synthesis of which has been reported before, was found to be converted into (I) on mercaptolysis.

View full abstract

In whole stages of Bombyx silkworm it was shown with gas-liquid chromatographic systems that silkworm-sterols consist of three sterols such as cholesterol, β-sitosterol, and campesterol, at least, and the sterols in the 5th instar larva contain afore-mentioned three sterols and an additional unknown sterol. Moreover, the sterol composition of the silkworm was studied in various stages.

View full abstract

In the course of screening research on new insecticides among metabolites of microorganisms, two active components were isolated from mycellia of Streptomyces sp. 16-22. The names, Piericidin A and B, were proposed to these active metabolites. Isolation procedure, physical and chemical properties and physiological activities of Piericidin A were presented. From the results of taxonomic study on Streptomyces sp. 16-22, it was found that this is a new species, to which the name, Streptomyces mobaraensis Nagatsu et Suzuki, was proposed.

View full abstract

Molecular formula C₂₅H_37-39NO₄ was assigned to Piericidin A. Through the examination of the ultraviolet, infrared and n.m.r. spectra and of chemical evidences, it was shown that Piericidin A contains one secondary alcohol, one acidic hydroxyl group, two methoxyl groups, tri-and tetra-substituted conjugated dienes and one polysubstituted heteroaromatic ring.

View full abstract

Malic acid-decomposing bacteria were isolated from wine and their morphological and cytochemical properties were investigated. The results showed that the bacteria isolated were classified into three groups, Lactobacillus plantarum and two unknown bacteria belonging to a certain Lactobacillus species. One of the unknown bacteria fermented arabinose and ribose faster than hexose. The other strain of the unknown bacteria required a certain factor derived from tomato juice for its growth, and the best growth of the bacteria occurred ribose containing medium supplied with the tomato juice factor (s).

View full abstract