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Atsushi TERUOKA, Toshikazu OHTSUKA, Yoshio HAYASE, Yusuke FUJITA, Shig ...
1989 Volume 14 Issue 1 Pages
1-10
Published: February 20, 1989
Released on J-STAGE: August 05, 2010
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We have synthesized a series of pyrethroidal ether compounds which have a dimethyl-(phenyl) silyl moiety and a
m-phenoxybenzyl or
m-phenoxypyridylmethyl moiety, and studied their insecticidal activity. Of these new pyrethroids, dimethyl(4-ethoxyphenyl)silylmethyl 3-phenoxybenzyl ether was the most effective and broad-spectrum in insecticidal activity and extremely low in fish toxicity.
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Structure-Activity Studies of Methanesulfonate Insecticides (Part 2)
Shoichi KATO, Akio MASUI, Shuichi ISHIDA
1989 Volume 14 Issue 1 Pages
11-22
Published: February 20, 1989
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6-Alkylthio-2-pyridyl alkanesulfonates, and their sulfoxides and sulfones were synthesized, and their lethal activity was tested to five species of insects and mites. Methanesulfonates, with 6-alkyl-thio, -sulfinyl and -sulfonyl substituents having one to six carbon atoms, showed remarkable insecticidal activity to
Nephotettix cincticeps, Nilaparvata lugens and
Culex pipiens. Insecticidal activity of 6-alkylthio-2-pyridyl methanesulfonates to strains of
Nephotettix cincticeps susceptible and resistant to organophosphates and carbamates was related parabolically to the hydrophobicity of the molecule, the optimum alkyl-thio substituents being C
3-C
4 alkyl groups. In a series of 6-
iso-butylthio-2-pyridyl alkanesulfonates and their sulfoxides and sulfones, the methane-, ethane- and chloromethane-sulfonates showed stronger insecticidal activity than higher alkanesulfonates. The 6-
n-propyl-sulfinyl-, -sulfonyl-, 6-
iso-butyl-sulfinyl- and -sulfonyl-2-pyridyl methanesulfonates and the 6-
iso-butylsulfonyl-substituted ethanesulfonate showed strong inhibitory activity against acetylcholinesterase preparations from the susceptible and resistant strains of
Nephotettix cincticeps.
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Akira NAKAYAMA, Katsuyata IKURA, Kiyoshi KATSUURA, Sho HASHIMOTO, Akir ...
1989 Volume 14 Issue 1 Pages
23-37
Published: February 20, 1989
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Fungicidal activity of triflumizole, (
E)-4-chloro-α, α, α-trifluoro-
N-(1-imidazol-1-yl-2-propoxyethylidene)-
o-toluidine, and its analogs against cucumber powdery mildew was analyzed quantitatively by using their physicochemical structural parameters and regression analysis. The result showed that steric, electronic and hydrophobic effects of substituents on the benzene ring were important for the fungicidal activity. The effects of substituents on the imino carbon were expressed by steric and hydrophobic parameters as well as indicator variables for α, β-unsaturated and β-oxy structures. Conformational analyses and computer graphics were employed to study the mode of interaction of triflumizole with cytochrome
P-450, the target enzyme of fungicidal azoles. An energy minimum structure of triflumizole was found to fit the cavity of cytochrome
P-450 so as to block the oxidation of lanosterol, the ergosterol precursor. The result of regression analysis and the computer graphics model suggested that steric and hydrophobic properties of imidazole derivatives are important to inhibit the biosynthesis of ergosterol by antagonizing cytochrome
P-450 oxidase.
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Survey of Pesticide Residues in Japanese Tea Leaves (Part 1)
Toshihiro NAGAYAMA, Toshio MAKI, Kimiko KAN, Mami IIDA, Yukihiro TAMUR ...
1989 Volume 14 Issue 1 Pages
39-45
Published: February 20, 1989
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In our investigation on organophosphorus pesticides in commercial tea leaves using thirty kinds of insecticides and two kinds of fungicides, we detected residues of one to eight insecticides in several kinds of tea leaves. Concentrations of fenitrothion (MEP), EPN, isoxathion, prothiofos and methidathion (DMTP) were trace-0.18, trace-0.59, 0.01-2.8, trace-1.5 and trace-0.03ppm respectively in more than half the investigated tea leaves, while those of phosalone, chlorfenvinphos (CVP; total of CVP-E and CVP-Z), chlorpyrifos, piridaphenthion and dialifor were trace-0.18, trace-3.4, 0.02-0.05, 0.15-0.46 and 0.01ppm respectively. Several of these insecticides remained in identical tea leaves. Neither concentration of insecticides nor kind of tea leaves made any significant difference. There was also little discrepancy in producing regions. The identification ratio was as high as 72-92% for MEP, isoxathion and EPN, and the content of CVP, isoxathion and prothiofos in residue was more than 1ppm in six samples. CVP, in particular, was at a level higher than 3ppm, leaching into tea by more than 12% from leaves. On the other side, isoxathion and prothiofos at more than 1ppm in samples leached by less than 5%. Both DMTP and MEP concentrations were less than 0.18ppm, even though they leached by more than 17%. In other words, CVP was high in both residual level and leaching ratio, while other insecticides were low in either level.
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Rong TSAO, Morifusa ETO
1989 Volume 14 Issue 1 Pages
47-51
Published: February 20, 1989
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The insecticide cartap hydrochloride,
S,
S′-[2-(dimethylamino)trimethylene]bis (thiocarbamate), was oxidized with
N-bromosuccinimide to give nereistoxin, 4-
N,
N-dimethyl-amino-1, 2-dithiolane. Nereistoxin was also produced as a main product through photoreaction under UV irradiation by a high pressure mercury lamp (λ>300nm) and UV lamps (λ=254 and 373nm) in aqueous and methanolic solutions, and on glass and silica gel surfaces, respectively. It is assumed that both the chemical and photo-induced oxidations led to the direct formation of nereistoxin. Decomposition was faster on the silica gel surface than on the glass surface, probably owing to the larger surface area of the former. Effects of some photosensitizers were also investigated, among which rose bengal and chlorophyllin showed a great accelerating effect on cartap photodecomposition.
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Yasuyuki KATAYAMA, Fumio HORIDE, Kozo TSUJI
1989 Volume 14 Issue 1 Pages
53-58
Published: February 20, 1989
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The stability of various pyrethroids in mineral carriers was studied in the presence or absence of malathion. All the pyrethroids studied were stable in mineral carriers in the absence of malathion. The pyrethroids having a cyano group in their alcohol moiety were significantly unstable in the presence of malathion, while the pyrethroids having no cyano group in their alcohol moiety were stable even in the presence of malathion. The decomposition seems to be caused by the reaction between the cyano group and some acidic, though unidentified, materials formed by the degradation of malathion in the mineral carriers. The results of mass,
1H NMR, and IR spectra suggested that the decomposition product was formed through the conversion of a cyano group to a (methylthio)carbonyl group. Some kinds of alkali or alkaline earth metal salts of weak acids, such as calcium carbonate, calcium acetate, sodium phosphate acted as stabilizers for these pyrethroids in the presence of malathion without having any significant effect on the stability of malathion.
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Toshiyuki KATAGI, Nobuyoshi MIKAMI, Tadashi MATSUDA, Junshi MIYAMOTO
1989 Volume 14 Issue 1 Pages
59-68
Published: February 20, 1989
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We estimated lower energy conformers of natural juvenile hormone III (JH III) [methyl-(2
E, 6
E)-3, 7, 11-trimethyl-(10
R, 11)-epoxy-dodecadienoate] based on semi-empirical molecular orbital (MO) MNDO calculations. Conformational analysis by PCILO calculations strongly suggested that JH III possesses an extended conformation and that the two methyl groups at the 3- and 7-positions partially restrict the internal rotations along the carbon chain of dodecadienoate. The same extended conformation was also suggested by phase-sensitive NOESY 2D-NMR measurements. The interatomic distance (
L) between the carbonyl carbon and epoxy oxygen atoms and the molecular dimensions of JH III were estimated to be 11.34±0.36Å and 18.5×8.2×7.2 Å, respectively. MNDO calculations, with model enzyme systems, suggested that metabolic oxidation at the (6
E)-C=C moiety and hydrolysis both at the ester linkage and epoxide moiety are feasible.
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Akira SHUTO, Mayumi OHGAI, Morifusa ETO
1989 Volume 14 Issue 1 Pages
69-74
Published: February 20, 1989
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We screened chemicals that inhibit tryptophan synthase for the purpose of finding the leads of herbicide candidates and found two potent inhibitors, 4-(dimethylamino)pyridine and 2-mercaptobenzimidazole; the former did not show any marked effect on rice (
Oryza sativa) plants, whereas the latter showed considerable phytotoxicity to rice seedlings.
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Tadataka TSUDA, Tomohiro OKAMOTO, Hitoshi KURONO, Hiroo UEDA
1989 Volume 14 Issue 1 Pages
75-77
Published: February 20, 1989
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Fifteen pyrazino [2, 3-
d] pyridazines were prepared by condensing four kinds of 2, 3-disubstituted pyrazinedicarboxylic anhydrides with hydrazine, methylhydrazine, phenylhydrazine and dimethylhydrazine. The condensates underwent chemical modifications and additional reactions to four kinds of dicyanopyrazines with hydrazine to prepare total thirty-two compounds, which were examined for pesticidal activity. Among them 2-phenyl-5, 8-diacetoxypyrazino [2, 3-
d] pyridazine showed protective activity against downy mildew of cucumber.
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Toshiyuki KATAGI, Nobuyoshi MIKAMI, Tadashi MATSUDA
1989 Volume 14 Issue 1 Pages
79-83
Published: February 20, 1989
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Norio KURIHARA, Reiji ICHINOSE, Sachiko TAKAO
1989 Volume 14 Issue 1 Pages
85-87
Published: February 20, 1989
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Fumio HORIDE, Kozo TSUJI, Masao SASAKI, Masao MINOBE
1989 Volume 14 Issue 1 Pages
89-92
Published: February 20, 1989
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Toshiyuki KATAGI, Yasuyuki KURITA
1989 Volume 14 Issue 1 Pages
93-99
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
103-107
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
109-112
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
113-118
Published: February 20, 1989
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[in Japanese], [in Japanese]
1989 Volume 14 Issue 1 Pages
119-120
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
121-123
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
124-125
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
126-127
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
128-130
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
131-133
Published: February 20, 1989
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[in Japanese]
1989 Volume 14 Issue 1 Pages
134-135
Published: February 20, 1989
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[in Japanese], [in Japanese]
1989 Volume 14 Issue 1 Pages
136-138
Published: February 20, 1989
Released on J-STAGE: August 05, 2010
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