We studied multi residue method of pesticides using Luke Method extraction, gel permeation chromatography (GPC) and dual column GC. A sample was extracted with acetone and filtered. Aliquot of the extracts was extracted with dichloromethane-petroleum ether (1:1) without evaporation of acetone. The extract was dehydrated, evaporated in vacuo, dissolved in dichloromethane-cyclohexane (1:1) and cleaned up by GPC using Bio Beads S-X3 and mobile phase dichloromethane-cyclohexane (1:1). The eluate fraction of pesticides was evaporated in vacuo and dissolved in acetone. The sample was determined with a dual column GC (column DB-1 and DB-1701, or DB-210 and DB-1) equipped with NPD and FPD. Silica gel column fractionation was effective for furthermore clean-up. Recoveries of 65 organic phosphate, carbamate and nitrogen containing pesticides from fortified tomato, lettuce and strawberry ranged 53-122%, except propamocarb, acephate, methamidophos and aldicarb. This multi residue method is fast and convenient to determine pesticide residues in crops.

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Reaction of benzylideneaminoguanidines (Ia-h) with ethyl N-cyanoformimidate (II) in acetonitrile at room temperature gave 1-benzylideneamino-2-cyanoiminomethyl guanidines (IIIa-h). 1-Halogenobenzylideneamino-3-methylguanidines (Ii and Ij) reacted with II directly to give 7-methylamino-2-halogenophenyl-1, 2, 4-triazolo[1, 5-a]-1, 3, 5-triazines (Vi and Vj) under similar conditions. The 1-benzylideneamino-2-cyanoiminomethyl gaunidines (III) were readily cyclized to the corresponding 1, 2-dihydro-1, 2, 4-triazolo[1, 5-a]-1, 3, 5-triazines (IV) by brief heating in methanol. The dihydrotriazolotriazines (IV) were oxidized with iodine in ethanol to give the corresponding 1, 2, 4-triazolo[1, 5-a]-1, 3, 5-triazines (V). Phytotoxic activities of the newly synthesized compounds (III, IV and V) were assayed using green microalgae, Scenedesmus acutus. 7-Amino-2-(4-chloro-2-fluorophenyl)-1, 2, 4-triazolo[1, 5-a]-1, 3, 5-triazine (Vh; sample 11) and some other compounds were found to suppress the cell growth and chlorophyll formation of Scenedesmus, but those activities were still not good enough to be utilized as a herbicide or plant growth regulator.

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Fungicidal properties of a new fungicide, fluazinam (IKF-1216) were investigated. Fluazinam had a broad fungicidal spectrum in antifungal test in vitro. It showed a good preventive efficacy against plant diseases caused by species of Botrytis, Colletotrichum, Phytophthora, Pseudoperonospora, Pyricularia, Sclerotinia and Venturia in a glasshouse test. Fluazinam had little curative and systemic efficacies; however, it showed a good residual efficacy with rain fastness against cucumber gray mold and tomato late blight. Furthermore, fluazinam was active against isolates of Phytophthora infestans which differed in sensitivity to metalaxyl. It also showed a high efficacy against the disease caused by benomyl-and procymidone-resistant isolates of Botrytis cinerea.

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Using autotrophic Scenedesmus cells and maize protoporphyrinogen-IX oxidase, twelve pyrazole compounds recently synthesized were assayed with respect to peroxidizing phytotoxic activity. Three pyrazoles, namely 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3, 5-dimethyl-4-nitropyrazole, 5-amino-4-cyano-1-(2, 6-dichloro-4-trifluoromethylphenyl)pyrazole and 5-chloro-1-(4-chloro-5-difluoromethoxy-2-fluorophenyl)-3, 4-tetramethylenepyrazole, strongly inhibited growth of the Scenedesmus cells and caused severe chlorophyll deficiency (bleaching activity) at a 10^-6M concentration. The three pyrazoles mentioned were selected for a further quantitative study to determine whether the chlorophyll decrease observed was due to inhibition of pigment biosynthesis or to peroxidative destruction of existing chlorophyll. The pyrazoles inhibited protoporphyrinogen-IX oxidase, caused not only accumulation of protoporphyrin-IX but also light-induced ethane formation. Thus, the three pyrazoles (1, 11 and 12) were identified as peroxidizing herbicides. A 1-(4-chloro-2-fluoro-5-substituted)-phenyl moiety at the pyrazole ring appears to be essential for producing active peroxidizing compounds.

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Pentachloronitrobenzene (PCNB) degrading microorganisms were screened from soil samples. Each soil sample was cultured at 28°C for 7 days with or without shaking in a mineral salt medium containing 0.1% of yeast extract and 50μg/ml PCNB. In 92 of 114 samples, 20 to 80% of PCNB degradation was observed in still cultivation, suggesting that PCNB degrading microorganisms exist in most soil environments irrespective of previous application of PCNB to the field. From the soil samples indicating a high degradation rate, an isolate I-41 was selected to be the strongest degrader of PCNB and it was identified as Pseudomonas aeruginosa. The bacterium degraded PCNB almost completely at the concentration of 10μg/ml under still conditions within a week, while it degraded only 18% of PCNB under shaking conditions, suggesting that I-41 can metabolize PCNB more efficiently under anaerobic conditions. The principal metabolic product of PCNB by I-41 was proved to be pentachioroaniline (PCA) by GC/MS. The results suggest that the main degradation pathway of PCNB in soil environment would be reduction of PCNB to PCA. The bacterial growth reached the stationary phase within 2 days, and the reduction of PCNB began inci-dentally to the bacterial growth. Both rates of the bacterial growth and PCNB metabolism were highest at the yeast extract concentration of 0.5-1.0%. When more than 200μg/ml of PCNB was added to the culture medium, both bacterial growth and PCNB metabolism were suppressed possibly due to high concentration of PCNB and highly accumulated PCA in the culture medium as well. I-41 metabolized not only PCNB but also its related compounds such as nitrochlorobenzenes. By a test with cell free extract of I-41, this reductive degradation was confirmed to have been processed by an enzymatic reaction.

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Propargyl N-(6-ethyl-5-iodo-2-pyridyl)carbamate (PEIP) exhibited high fungitoxic activities against Erysiphe graminis f. sp. tritici, Sclerotinia sclerotiorum, Botrytis cinerea, Pyricularia oryzae, and Rhizoctonia solani at 0.1ppm in vitro and 8 to 63ppm in vivo. It also showed activity against benzimidazole-resistant isolates of B. cinerea as well as the sensitive isolates. PEIP possessed not only preventive activity, but also curative activity and translaminar action. The excellent activity of PEIP against B. cinerea and Elsinoe ampelina was also confirmed in field trials. PEIP induced morphological changes in the conidial germination and nuclear arrangement in germ-tubes of B. cinerea in a similar manner to that of benomyl, a benzimidazole fungicide. These results suggest that PEIP interferes with the cell division of this fungus.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Technical benfuresate was of very low acute oral and dermal and low acute inhalational toxicity to rodents. Repeat dose studies in the rat, mouse and dog showed the material to be well tolerated with the maximally tolerated doses of 318, 561 and 400mg/kg/day, respectively. Histopathology showed the kidney to be the main target organ in all three species. The principal findings in the kidney, found following subchronic exposure in the rat and following subchronic/chronic exposure in the mouse and dog were papillary necrosis and dilatation and/or degeneration of the proximal tubules (and collecting ducts in rats). These findings were associated with elevated kidney weights in the rat and dog, pyelonephritis in the mouse and dog and interstitial nephritis in the rat and dog.
The liver was also a target organ at dose levels above the MTD in the rat and mouse as indicated by swelling of the periportal hepatocytes and centrilobular enlargement, respectively.
There was no evidence of oncogenicity in the mouse or rat and the NOEL in the most sensitive species, the rat, was 3mg/kg/day.
Technical benfuresate was non-genotoxic, non-irritant, had no effect on reproduction or fertility and was not a skin sensitiser.
The compound was rapidly and completely absorbed. Tissue residues were low and declined rapidly. The highest levels were found in the kidney and fat after 6hr. Metabolism of the compound in the rat was rapid and complete as was elimination, which was predominantly via the urine.
The compound showed weak pharmacological effects on the nervous system following oral administration and the circulatory and respiratory systems, but only after intravenous dosage.
The acute toxicity of metabolites, process intermediates and formulations of benfuresate were low.
It is concluded therefore that under the recommended conditions of use both technical benfuresate and formulations are unlikely to present hazard to operators or the public who may consume negligible residues from treated produce.

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