Structures, absorption spectra, and stabilities of magnesium chelates of 1-hydroxyanthraquinone and 1, 4-dihydroxyanthraquinone were examined by the spectrophotometric method. 1-Hydroxyanthraquinone reacts with magnesium in alcoholic solution to form a 2: 1 chelate compound (I), while 1, 4-dihydroxyanthraquinone forms a 1: 1 chelate compound, which is probably a polymer (II).

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Vitamin D₂ and vitamin D₃ gave a single reduction-wave, respectively, in polarography in acetonitrile containing 0.05 M-tetrabutylammonium iodide. The reduction-wave of vitamin was indistinguishable from that of vitamin D2, whose half-wave potentials were evaluated identically at -2.1₀ V vs. Hg. Proportionalities between wave-height and concentration were in the concentration range from 4×10^-4 M (ca. 6000 IU·Eml^-1) to 1.2×10M (ca. 18000 IUD·ml^-1).
In both cases, the conjugated three double-bond system may be reduced to two doublebond system, which corresponds to the third reduction-step of vitamin A.
Ergosterol which has a conjugated two double-bond system and an isolated double-bond gave no reduction-wave under the present conditions.

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Highly purified aspartic β-semialdehyde dehydrogenase was prepared from pea seedlings. The optimum pH and Km values for the substrates were determined, and the substrate and coenzyme specificities of this enzyme were examined.

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Effects of various compounds on aspartic β-semialdehyde dehydrogenase prepared from pea seedlings were examined. From the behaviours toward thioglycolate and PCMB, this enzyme was concluded to be a -SH enzyme. The inhibitory effects of aldehydes and amino acids were also studied.

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A synthesis of a compound of gibberic acid type is described.

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In connection with the synthesis of gibberic acid several new hydrindonecarboxylic acids were prepared.

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Synthesis of several new compounds with phyllocladene skeleton is described. Attempted transformation of phyllocladene skeleton into gibberellin skeleton is also described.

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The activities of various enzymes were examined in the first and second leaves of rice seedlings treated with gibberellin A. GIB treatment resulted in more or less decrease in the activities of malic dehydrogenase, alcohol dehydrogenase, pyruvic carboxylase, glutamic-aspartic transaminase, glutamic decarboxylase, glycolic acid oxidase and cytochrome oxidase on the basis of the enzyme solution. Increase in peroxidase activity was remarkable by GIB treatment when guaiacol and pyrogallol were used as hydrogen donor, but increase was not so much by use of p-phenylenediamine and p-methylaminophenol sulfate.

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1, 6, 8-Trimethoxy-3-hydroxymethy l-2-naphthoic acid lactone (IV) was synthesized from benzoic acid in 21 steps. This lactone (IV) was completely identical with authentic dimethyl α-sorigenin, obtained by the methylation of natural α-sorigenin. Herewith the structure of α-sorigenin was confirmed to be 1, 8-dihydroxy-6-methoxy-3-hydroxymethy l-2-naphthoic acid lactone (III).

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Alkaline degradation of rubrofusarin and nor-rubrofusarin were studicd; nor-rubrofusarin readily underwent hydrolysis to give a tetrahydroxynaphthalcne, acetone, and acetic acid; whereas, rubrofusarin, after prolonged time of hydrolysis, yielded a β-methoxytrihydroxynaphthalene instead of the naphthol. Physical and chemical studies revealed that the naphthol is 1, 3, 6, 8-tetrahydroxynaphthalene and it has been confirmed by the synthesis from chromotropic acid (disodium salt). Thus, evidently, rubrofusarin has a naphthalene nucleus to which a methoxyl group is attached at β-position. The formation, on the hydrolysis, of acetone and acetic acid, along with the naphthol, indicates the presence of 2-methyl-γ-pyrone structure in rubrofusarin.

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With an assumption that the laver-like odor of green tea is due to dimethyl sulfide, an attempt to isolate dimethyl sulfide from commercial green tea was made, and the identification of dimethyl sulfide was successful by making the co-ordinated compound with mercuric chloride, 2 (CH₃)₂S·3HgCl₂. In addition, the presence of methylmethionine sulfonium salt in tea extract as a precursor of dimethyl sulfide was examined.

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N-Acetyl-_D-galactosamine, N-acetyl-_D-mannosamine and N-acetyl-D-glucosamine were allowed to react with oxalacetic acid under alkaline conditions, and the condensation products purified by ion-exchange chromatography. Properties of these products on the whole are similar to each other, though there is a minor but significant difference in the condensation product with N-acetyl-_D-galactosamine. Paper chromatograms of the condensation products suggest that N-acetyl-_D-galactosamine as well as N-acetyl-_D-glucosamine are epimerized partly before they condense with oxalacetic acid to give each two sialic acids with different configurations at C-5 from each other.

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Kojic acid has a slight stimulatory effect on plant growth as measured by the use of duckweed grown under aseptic conditions on a synthetic liquid medium. It is thought that this stimulation is due to the formation of chelatcs. This presentation is primarily concerned with the effect of various derivatives of kojic acid, particularly halogenated derivatives, on plant growth as measured by this same system. Halogenation of the 2-position results in toxic compounds. Substitution in the 6-position results in compounds with beneficial growth effects. Blockage of the 5-position causes a loss of stimulatory ability, interpreted as a loss of chelating power.

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