A new herbicide, alloxydim-sodium(ADS) [sodium salt of 2-(1-allyloxyamino)-butylidene-5, 5-dimethyl-4-methoxycarbonylcyclohexane-1, 3-dione] was applied to the leaves of sugar beet (Beta vulgaris). The total recovery of the radioactivity of ¹⁴C-ADS, labeled at C-1 position of the butylidene group, gradually decreased with half-life of 11 days. The translocation of the radioactivity to other parts of the plant was little and the residues calculated as apparent ADS in roots were 0.16, 0.0096 and 0.0020ppm at 1.5, 4 and 6 months after the treatment, respectively. The main metabolite in the treated leaves was a deallyloxylated compound (CM-I) and minor ones were two oxo-tetrahydrobenzoxazole derivatives (CM-II, CM-III). The amounts of these metabolites reached the maximum around 10 days with 18.0% (CM-I), 2.6% (CM-II) and 2.5% (CM-III) of the applied radioactivity. This type of transformation of ADS also occurred under non-biological conditions, and the mechanism is discussed.

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Isoprothiolane (diisopropyl 1, 3-dithiolan-2-ylidenemalonate, Fuji-One^®) caused swelling of germ tubes and tips of growing mycelia of Pyricularia oryzae. Fifty μg/ml of isoprothiolane strongly inhibited the incorporation of ¹⁴C-sugars such as ribose, galactose, mannose and glucose into cell wall and also inhibited the uptake of the above ¹⁴C-sugars from nutrient medium at the same level as the inhibition of incorporation into cell wall, whereas it did not inhibit both uptake by fungal cells and incorporation of ¹⁴C-glucosamine into cell wall. Therefore, swelling phenomenon may be due to the inhibition of sugar uptake by isoprothiolane.

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The sample brown rice was powdered and soaked in 0.1N hydrochloric acid then extracted with 0.1% dithizone chloroform solution. The organic mercury in the extract was separated by tlc with hexane-chloroform (1+1), and then determined by atomic absorption spectrometry. Ninety eight percent as mean recovery was obtained from the brown rice added methylmercury in levels of 43 and 85ppb. The minimum detectable limit was 5ppb in the procedure that spent 8g of brown rice in the final and gave 38ng of Hg in the blank test. A few percent of inorganic mercury might be erroneously detected as organic mercury. The brown rice that yielded on the soil 12 years after being mixed with phenylmercury at the rate of 150g Hg/ a showed 25ppb of organic mercury content, which was identified as phenylmercury by gaschromatography.

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On either a single oral dose or 5 consecutive daily doses, the metabolism of fenvalerate [α-cyano-3-phenoxybenzyl-2-(4-chlorophenyl) isovalerate] and the (S)-acid ester isomer in male rats was rapid, and the acid moiety and the aromatic portion of the alcohol moiety were almost completely eliminated from the body within several days. The CN group of the alcohol moiety was rapidly converted mainly to thiocyanate which retained relatively longer in selective tissues including skin and hair. Fenvalerate and the (S)-acid isomer yielded two fecal ester metabolites which resulted from hydroxylation at the 4′- and 2′-phenoxy positions. Other significant metabolites were 3-phenoxybenzoic acid and its hydroxy derivatives (free and conjugates) from the alcohol-labeled compound, 3-(4-chlorophenyl) iso-valeric acid and its hydroxy derivatives (free, lactones and conjugates) from the acid-labeled compound, and thiocyanate and CO₂ from the CN-labeled compounds. There were no apparent differences in the nature and amount of metabolites, and in the patterns of ¹⁴C excretion and tissue residues between fenvalerate and the (S)-acid isomer.

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Degradation of CNP, 2, 4, 6-trichlorophenyl 4′-nitrophenyl ether, in a flooded soil under oxidative (aerobic) and reductive (anaerobic) conditions was studied in the laboratory using ¹⁴C-CNP labelled at each of the benzene rings. The degradation rate of CNP differed depending upon the redox potential of the soil. The half-life period was 6 to 7 days under oxidative conditions and 1 to 2 days under reductive conditions. Degradation of CNP under oxidative conditions started after a short lag-period. The degradation products were identified as 2, 4, 6-trichlorophenyl 4′-aminophenyl ether, 2, 4, 6-trichlorophenyl 4′-acetylaminophenyl ether, 2, 4, 6-trichlorophenyl 4′-hydroxyphenyl ether, 2, 4, 6-trichlorophenol, p-nitrophenol, and p-aminophenol by tlc. Major products were the acylamino derivatives which under reductive conditions reached about 15.5% of applied radioactivity after 2 days and then decreased thereafter. The other products were detected only in small amounts. Most of the radioactivity was strongly adsorbed to the soil within a few days and was unextractable with organic solvents. This was attributed to complex formation between the amino derivative and soil constituents. More ¹⁴CO₂ was liberated under oxidative, than reductive, flooded conditions.

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Although by single oral treatment of rats with ¹⁴C- or ³H-procymidone [Sumilex^®, N-(3′, 5′-dichlorophenyl)-1, 2-dimethylcyclopropane-1, 2-dicarboximide] the radioactivity was readily absorbed and distributed into various tissues, excretion of the radioactivity proceeded rapidly and substantially completely within a few days, majorly in the urine, regardless of the radiolabeling sites, sexes and pregnancy of the rats treated. The cumulative excretion patterns of the radiocarbon were not altered by consecutive administration. Upon single oral treatment with ¹⁴C-procymidone to pregnant rats, the radiocarbon in fetus disappeared promptly with the decrease of the radiocarbon in maternal blood. Procymidone was readily and extensively metabolized by ways of hydroxylation at methyl group, subsequent oxidation to carboxylic acid and hydrolysis of cyclic imide or amide linkage. Most of these metabolites were found in both urine and feces. In addition, small amounts of intact procymidone were detected only in the feces. The relative amounts of these products were not significantly changed by consecutive treatment.

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On oral administration of ¹⁴C-fenitrothion [Sumithion^®, O, O-dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate] labeled at the phenyl ring to Japanese quails at a single dose of 5mg/kg or to White Leghorn hens at daily dose of 2mg/kg for 7 days, 97 to 99% of the radiocarbon administered was excreted in the mixture of urine and feces within one day. The radioactivity eliminated into eggs was at most 0.2%, or 0.055ppm equivalent to the parent compound. More than 18 metabolites were found in the excreta, among which 14 compounds were identified. The major metabolites were 3-methyl-4-nitrophenol and its sulfate conjugate which accounted for 70.5% of the dose in quails and 50.8% in hens. Desmethylfenitrothion and des-methylfenitrooxon were found as minor metabolites, and also several m-methyl oxidation products were detected. In vitro studies revealed that hen, quail, pheasant and duck liver enzymes possessed higher oxidation activity at the m-methyl group of fenitrooxon than that of mammalian liver enzymes, although these avian enzymes had extremely low O-demethylate activity.

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Previous works have shown that Pseudomonas aeruginosa produces ovipositional attractants for several species of mosquitos on capric acid substrate in laboratory and field. In the present work, we isolated an attractant for Aedes aegypti from the bacterial culture medium by thin layer and gas chromatography, and identified it by mass spectroscopy as 7, 11-dimethyloctadecane. This identification was confirmed with synthesis of this hydrocarbon by two methods, Grignard coupling reaction and a combination of acetonylation and Wittig reaction. The synthetic one showed the identical mass-fragmentation pattern and the GC-retention time with those of the isolated one. However, there was some discrepancy of atractancy between the isolated and synthetic ones; 6.9 times at a most attractive dosage vs. 2.9 times at 0.4mg/slide respectively. A minute attractive component included in the isolated fraction or the differential attractancy of the diastereomers of the synthetic hydrocarbon is suggested for the discrepancy.

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Metabolic fate of 1, 2-dibromo-3-chloropropane (DBCP) was investigated in male Wistar rats orally treated with 20mg/kg of 3-¹⁴C-1, 2-dibromo-3-chloropropane. Greater than 99% of the dose was absorbed, actively metabolized, and eliminated (84.9% of dose in 48hr) in the urine, bile, and expired air. Radiocarbon expired was consisted mainly of radioactive carbon dioxide and also included a trace level of DBCP. Radiocarbon excreted in the urine was consisted of amphoteric and ninhydrinepositive conjugates (molecular weights, around 500) and 10 kinds of minor metabolites. Unchanged DBCP was not detected in the urine. Almost all of the tissues showed higher tissue radiocarbon levels than the plasma levels throughout the experimental term (28 days), and preferent distribution of radiocarbon was observed in the kidney and liver. Radiocarbon in tissues was classified into 3 groups as DBCP, organic-solvents extractable metabolites, and unextractable residue. DBCP consisted of only a part of tissue radiocarbon and was cumulative only in the adipose tissue. Organic-solvents extractable metabolites occupied the 2nd part and was considered cumulative. Predominant chemical form of tissue radiocarbon was organic-solvents unextractable substance typically observed in the kidney and liver.

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Fungitoxicity of isoprothiolane was remarkably affected by the kind of sugar in culture medium. The minimum inhibotory concentration (MIC) of isoprothiolane for mycelial growth of Pyricularia oryzae was less than 5μg/ml in culture medium containing ribose: whereas, the MIC in glucose-yeast extract medium was more than 20μg/ml. Isoprothiolane was metabolized more rapidly by P. oryzae grown in ribose-yeast extract liquid medium than in glucose-yeast extract liquid medium. In ribose-yeast extract liquid medium, mycelial growth of P. oryzae was not inhibited by 5μg/ml isoprothiolane for the first 24hr-incubation period. However, after 24hr-incubation, when a large amount of isoprothiolane may have been metabolized to the other compounds, the inhibition of growth by isoprothiolane was observed.

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The systematic identification and determination of pesticides, combined with column, thin-layer and gas chromatography, was applied to the multiresidue analysis. The application to pesticides in the first and second divisions —mainly organochlorine pesticides— was described in the previous paper. Now, organophosphorus pesticides in the second to the sixth division were examined. These pesticides such as disulfoton, salithion, fenitrothion, malathion, dichlorvos, etc. were added, respectively, to 10g of corn sample at the level of residue analysis since the corn appeared to have some difficulties in analysis because of being rich in oils and coloring materials. More than 80% of these pesticides were recovered from the corn with a few exceptions. Therefore, it was found that organophosphorus pesticides in corn samples could be separated from each other and determined at the level of residue analysis by this systematic method of pesticides.

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The susceptibility of adults and larvae of the rice leaf beetle, Lema oryzae, to propoxur was determined by topical application. Also, comparison of susceptibility of overwintered female beetles collected from 17 spots in 10 prefectures to propoxur, carbaryl, phenthoate and phosmet were made. No significant differences of the susceptibility levels to tested insecticides were observed among the beetles from various localities. As averages of LD₅₀ values of propoxur (0.0023μg), carbaryl (0.0095μg), and phenthoate (0.10μg) determined in this study were very similar to those which reported by Inoue & Okuyama in 1969, the resistance of this insect to organophosphorus and carbamate insecticides was not found.

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Spectrophotometric determination of some pesticides were investigated. Dinitrocyclohexylphenols with strong yellow colour in basic solution were directly estimated by spectrophotometry. Fenitrothion was converted to p-nitro-o-cresol by boiling in basic ethanol and nitrocresol was determined spectrophotomecally. Gottlieb's method of pentachlorophenol using 4-aminoantipyrin were proved to be more selective than titration method published by JIS and WHO. Stability of pentachlorophenol in water was studied using this colorimetry. Cellocidin (acetylenedicarboxamide) was refluxed in ammonia water and resulting 1-amino-1, 2-ethylenedicarboxamide with strong absorption peak at 296nm was assayed by spectrophotometry. Dithianone was redused with sodium sulfide in methanol and resulting yellow colour was measured. The methods mentioned above were accepted as official methods of analysis of pesticide formulations by Ministry of Agriculture, Forestry and Fishery. Simple infrared spectrophotometry of technical aldrin, tetradifon, heptachlor, naled and trichlorfon was established. The combination of spectrophotometric assay and separation by thin-layer chromatography presented exact and precise methods of analysis of mecarbam, aldrin, DCPM and CPCBS.
Persistency of parathion in fruit, vegetable and rice were investigated using Averell-Norris's and Buckley's colorimery. Averell-Norris's method based on diazo-coupling reaction was applied to microdetermination of nitrofen, quintozene and herbicides with chloroaniline group. Nitrofen and quintozene were reduced with zinc dust and hydrochloric acid, the herbicides were hydrolysed with acid or alkali and resulting chloroanilines were subjected to diazo-coupling reaction. Loose-layer chromatography was used as clean up procedure. Methods of residue analysis of naphthalene-acetic acid, carbaryl, benomyl, thiophanate-methyl and naproanilide using high-speed liquid chromatograph equiped with fluorophotometer were established and proved to be very convinient, precise and sensitive.

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The biological structure-activity relationships can be analyzed by means of a procedure similar to what has been used to elucidate physical organic structure-reactivity relationships. Using the Hammett-Taft substituent parameters such as σ, σ* and E_S for electronic and steric factors and the parameter π for hydrophobicity defined from oil/water partition coefficients, structure-activity relationships of a number of series of biologically active compounds including pesticides have been analyzed quantitatively. By means of regression analysis, factors governing the variation in the magnitude of biological response are separated into respective terms of physicochemical parameters. By comparing the relative significance of each of the parameter terms with those observed for standard physical organic reactions and empirical rules accumulated for chemicobiological interactions, (sub) molecular modes of action of biologically active compunds can be delineated including mechanisms in the course of transport as well as those for the interaction with the target site in certain cases. This procedure named after Hansch has been used to such biological activities as nerve blocking of BHC and related compounds and acetylcholinesterase inhibition of phenyl N-methylcarbamate insecticides. The nerve blocking is attributed to nonspecific perturbation of nerve membrane due to hydrophobicity of molecule. The acetylcholinesterase inhibition with N-methylcarbamates is governed by positition-specific substituent effects such as biphasic electronic, hydrophobic and hydrogen bonding besides steric and proximity electronic effects of ortho substituents.

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The inoculation method of rice blast disease to the host plant in a inoculation chamber was first discovered in Japan and the method discovered made possible to find a new anti-biotic, Blastcidin S. This principle has been widely applied, and many other fungicides have been found to use practically.
The specialized apparatus composed of the usual turntables surrounded by the artifical environment helped to find a new systemic fungicide, Thiophanate, which is widely known over the world.
A simple method was successfully discovered for the screening of the soil-treatment-pesticides without distruction of the physical structure of the soil. Using this method, it was clarified that the penetration of the pesticide into the soil quite varied with its formulations. At present, the emulsion form is mostly used for the control of the insect pests in a deep part of the soil.
Granular formulation gave the best result for the control of insect pests in the rice paddy field. This finding resulted in discovery the new formulation, pesticide for submerged application.

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