The acceptability of thallium salts based on the behavioral response of rats was good in low concentrations, but decreased at concentrations over 0.125%, and the discrimination between the poison solutions and the plain water was clear, although a high degree of mortality was achieved at the concentrations of wide range and total ingested amount of fluid was normal value or near by it. The integrated response of the chorda tympani nerve against the application of thallium sulphate was clear in higher concentrations over 0.13% and the magnitude of the taste nerve response in five thallium salts at the concentration of the same molecule (0.48-1%, 0.02M) was almost the same. Accordingly, a cause for the low acceptability of thallium sulphate at higher concentrations is possibly due to unpleasant taste, although a toxic action of thallium salts also involves in the process of discrimination between water and the poison solution.
The gustatory effectiveness of thallium salts, both inorganic and organic salts, coumarin and its derivatives when measured through the chorda tympani nerve of rats, suggested that the gustatory effectiveness of thallium salts might be mainly caused by thallium ions.

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Myomycin, an antibiotic reported by French et al. in 1973, was tested for the biological effect on 7 species of plant pathogenic bacteria. The bacterial growth was perfectly inhibited at concentrations of 25 to 100μg/ml by agar dilution method. In turbidimetric method, perfect inhibitory concentration for the growth of those bacteria widely ranged from 2 to 100μg/ml. In agar diffusion method, inhibitory zones of those bacteria caused by myomycin were small even at a concentration of 100μg/ml. On the other hand, in vivo assay, myomycin remarkably protected Chinese cabbage against soft rot caused by Erwinia carotovora at 45μg/ml, and cucumber against angular leaf spot caused by Pseudomonas lachrymans at 75μg/ml, while the antibiotic did not suppress efficiently bacterial leaf blight of rice caused by Xanthomonas oryzae at 75μg/ml. Although the protective effect against angular leaf spot caused by a streptomycin-resistant strain of P. lachrymans was slightly less than in the case of sensitive strain, its protective value was higher than those of streptomycin and a copper compound.

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o-Phenylphenol (OPP) was investigated for its teratogenicity and mutagenicity. Pregnant Wistar rats were given orally OPP in a daily dose of 150, 300, 600, or 1, 200mg/kg on days 6 to 15 of gestation. Three hundred mg per kg or more of OPP manifested acute toxicity to dams and suppressed their body weight gain. Daily dose of 1, 200mg/kg of OPP was lethal for 10 of 11 dams administered. In 600mg/kg group, the fetal resorption was increased and the body weight of survival young was decreased significantly. Small number of fetuses had anomalies in all groups. These results indicate that OPP is not teratogenic in rats.
In the dominant-lethal assay, male C3H mice were administered orally 100 or 500mg/kg of OPP for 5 successive days. Mating trials began immediately after the treatment and continued for 6 weeks. No dominant-lethal mutations were induced in any group tested.

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Cucumber (Cucumis sativus L.) and komatsuna (Brassica rapa L.) grown in soils applied with BPMC took up BPMC through roots and BPMC was translocated to other plant portions. In cucumber, greater part of BPMC remained in root portion and the translocation rate to stems, leaves and fruits was generally low. On the other hand, the distribution of BPMC in komatsuna was seemingly uniform.
The amounts of BPMC taken up by two crops were different with the formulations of BPMC and the soil types. Uptake of BPMC by the crops was a little higher in fine granule than dust. The crops grown in alluvial soil took up greater amount of BPMC than those grown in volcanic ash soil, and the reason might be attributable to the low organic matter content in the alluvial soil. Rate of disappearance of BPMC in potted soil was faster in dust than fine granule, and BPMC moved from the surface layer to the lower layer of soil. Ratio of soil-bound residues of BPMC was higher in the soil applied with fine granule than dust.

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The mechanism of the antibacterial selectivity of 2-amino-1, 3, 4-thiadiazole (ATDA) was studied by the incorporation experiments of ¹⁴C-nicotinamide and ¹⁴C-nicotinic acid into NAD, using ATDA-sensitive Xanthomonas oryzae and X. citri, the insensitive Erwinia carotovora and Pseudomonas tabaci, and the resistant X. oryzae strain. In the sensitive bacteria, ¹⁴C-NAD was produced from ¹⁴C-nicotinamide, but not from ¹⁴C-nicotinic acid. The insensitive E. carotovora utilized both nicotinamide and nicotinic acid as precursors of NAD, but the insensitive P. tabaci and the resistant strain did not utilize the two precursors. ¹⁴C-NAD was also formed from ¹⁴C-nicotinamide in the cell extracts from the sensitive strain of X. oryzae, but not in the extracts from the resistant strain. ATDA is presumably integrated to NAD through the same pathway as nicotinamide in the sensitive bacteria. In the resistant strain, however, ATDA can not be integrated to NAD because of the loss of nicotinamide affinity of the enzymes involving in the synthesis of NAD from nicotinamide or the lack of the enzymes. The insensitivity of P. tabaci to ATDA also is due to the same mechanism as the resistant strain. In the insensitive E. carotovora, ATDA may be not integrated to NAD because of the divergent pathway of nicotinamide metabolism in NAD synthesis.

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The systematic identification and determination of many kinds of pesticides are attempted by a combination of column, thin-layer and gas chromatography. About one hundred pesticides were classified into six divisions and twenty two groups by thin-layer chromatography (tlc). In order to apply this systematic method of separation to the determination of pesticide residue in crops or soils, etc., the authors try to divide the pesticides into six fractions corresponding to the above divisions by column chromatography instead of tlc. Here, twelve pesticides in the Fifth were eluted from a column. That is, linuron, CPMC, and ACN were eluted into fractions III and IV, while MPMC, MTMC, simazine, propoxur, diphenamid, carbaryl, propanil, and dimethachlone were into fractions IV and V; chlorthiamid was mostly into fraction VI. These pesticides were separated from each other and determined by GC with ECD and FID, after being divided into three groups by thin-layer chromatography (tlc). Most of these pesticides were recovered more than 80%. Sixteen pesticides in the Sixth also were separated from each other and determined in the same procedure as described above. The majority of these pesticides were recovered over 75% through the whole procedure. Furthermore, the method for the systematic separation and identification of pesticides in the First to the Sixth is arranged in the schematic diagram.

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Chlorothalonil (tetrachloroisophtalonitrile) in benzene was unstable at a light place and unknown compounds appeared. This reaction occurred easily by sunlight through glass. A major photolysate of chlorothalonil in benzene was crystallized as colorless needles. The photolysate was identified as 2, 3, 5-trichloro-4, 6-dicyanobiphenyl by means of MS and CMR spectra. Similar photolysates of chlorothalonil occurred easily in other aromatic solvents at the light place and gave 3 peaks in toluene, 1 in o-xylene and 2 in mesitylene on the gas chromatogram, but no photochemical products was found in acetone, ether and hexane.

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The degradation of bifenox, a diphenyl ether herbicide, methyl 5-(2, 4-dichlorophenoxy)-2-nitrobenzoate, in 3 arable soils collected from paddy fields and a subsoil from forest was studied under flooded and upland moisture conditions in the laboratory using ¹⁴C-bifenox labeled at the nitrophenyl ring. A great difference in the degradation pattern was observed between upland and flooded conditions, but the differences among the soils were small. In paddy soils under flooded conditions, bifenox was degraded rapidly and the half life period was within 4 days when the chemical was applied at 10ppm level. Three major degradation products, the free acid and the amino derivatives of the ester and free acid forms; and 5 minor products, the acetyl- and formyl-amino derivatives of the ester and free acid forms and the salicylic acid derivative were identified. In non-flooded paddy soils, bifenox was also degraded rapidly and the half life was about 6 days. The free acid of bifenox was the main degradation product and the amino derivatives were hardly detected. In the flooded sub-soil which contained a trace amount of organic matter, the degradation was similar to those in non-flooded paddy soils.

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Several soil microbes, Mucor sufui and two other M. spp., Penicillium citrinum, P. glaucum, Aspergillus niger, Bacillus subtilis, Fusarium oxysporum and Trichoderma viride effectively degrade butachlor [2-chloro-2′, 6′-diethyl-N-(butoxy-methyl) acetanilide] in the 0.02M KH₂PO₄ buffer solution at pH 5.2 for fungi or pH 7.0 for bacteria. Three other soil microbes, A. oryzae, A. usamii and B. megatherium were found to be less effective, and Streptomyces sp. NTU-014 was unable to effectively degrade butachlor. Degradation of butachlor by M. sufui NTU-358 produced at least 8-12 metabolites. Among these products, 2-chloro-2′, 6′-diethyl-acetanilide, 2-hydroxy-2′, 6′-diethylacetanilide, 2, 6-diethylaniline, N-chloroacetyl-7-ethyl-2, 3-dihydroindole, 2′, 6′-diethylacetanilide and N-methyl-2-chloro-2′, 6′-diethylacetanilide were identified and the partial pathways involved in the degradation of butachlor were proposed. Recovery of butachlor in the autoclaved and non-autoclaved soils were found to be 74.5% and 26.3% respectively for 24 days incubation. It was presumed that the soil microbes may play an important role in the degradation of butachlor in soils.

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When carbonyl-¹⁴C-labeled 3, 5-xylyl methylcarbamate (XMC) and 3-tert-butylphenyl methylcarbamate (terbam) were topically applied on the adults of the green rice leafhopper, Nephotettix cincticeps Uhler, and the smaller brown planthopper, Laodelphax striatellus Fallén, penetration of radioactivity into the insect body was rapid. When the radioactivity taken up by insects was divided into three fractions, that is, water soluble, organosoluble, and unextracted, most of the radioactivity was found in the organosoluble fraction. Water soluble radioactivity gradually increased in course of time. Although parent compounds occupied 67-98% of organosoluble radioactivity, the ratio of metabolites gradually increased in course of time. Several metabolites were detected by tlc-radioautography. The distribution patterns of metabolites were different between the green rice leafhopper and the smaller brown planthopper. In vitro metabolism of XMC in microsome fraction of the green rice leafhopper was accelerated by the addition of NADPH₂ and was inhibited by piperonyl butoxide. Among several metabolites, N-hydroxymethyl derivatives of the insecticides were identified.

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Fortyone new 4-thiazolines have been synthesised by the condensation of unsymmetrical diarylthioureas of the type RNHCSNHR' with ketones in presence of bromine as the condensing agent. In majority of these condensations only one isomer has been isolated. All the prepared thiazolines have been tested for their ungicidal activity against Cochliobolus miyabeanus as the test fungus and the I₅₀ in ppm (50% inhibition) value have been reported in Table 1.

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A simple screening method of control chemicals for soft rot of vegetables was developed, by which many chemicals can be screened in a short time with ease. The syrindrical blocks from radish root were dipped into chemical solution for 1hr. Then the treated blocks were inoculated with Erwinia carotovora by drop inoculation. After incubation at 28°C for 20hr, the rotted part of the blocks was washed off with running water. By observing the residues, the protective effects of chemicals were estimated.

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[in Japanese]

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[in Japanese]

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