Research on the Actual Residues for Acetamiprid in Crops and Soils (in Japanese)
Research on the actual residues for acetamiprid, (E)-N1- [(6-chloro-3-pyridyl)methyl]-N2-cyano-N1-methylacetamidine (ATP) in crops and soils was performed using two analytical methods for determining the residues of ATP and its metabolites. One is the parent analytical method for ATP determination and the other is the common moiety method for ATP and its metabolites (its degradation products) determination in crops and soils. For soil, an individual analytical method for ATP and its degradation products determination was devised. Residue analyses of 8 crops to which water soluble concentrate was applied suggested that there were no remarkable difference in residue amounts obtained from both methods so that ATP made up most of the residue in crops, and its metabolites were negligible in amount. For granule application, residue amounts of ATP and its metabolites obtained from the common moiety method (4 crops) were less than limit of detection (LOD, 0.01 ppm) or near the LOD level more than 60 days after treatment. In case of soil, ATP degraded very rapidly and the half life of ATP itself was 1-2 days after treatment in container and field soils, and that of ATP and its degradation products were from 15 to 30 days after treatment in both conditions.
Key words: acetamiprid, crop, soil, residue analysis.
Flavanonol Glucoside and Proanthocyanidins: Oviposition Stimulants for the Cerambycid Beetle, Monochamus alternatus
An oviposition stimulant for the cerambycid beetle, Monochamus alternatus, from an aqueous acetone extract of inner bark of Pinus densiflora, was identified as a flavanonol glucoside, (-)-2,3-trans-dihydroquercetin-3'-O-b-D-glucopyranoside. Two dimeric proanthocyanidins, along with polymeric proanthocyanidins, were also isolated from the extract and identified as procyanidins B-1 [epicatechin-(4b®8')-catechin] and B-3 [catechin-(4a®8')-catechin]. In the presence of a fraction of the extract, a mixture of the polymers and either B-1 or B-3 stimulated oviposition of the female beetle. However, the glucoside, B-1, B-3 and the polymers were inactive alone.
Key words: Monochamus alternatus, Pinus denslflora, oviposition stimulants, (-)-2,3-trans-dihydroquercetin-3'-O-b-D-glucopyranoside, procyanidins B-1 and B-3, polymeric proanthocyanidins.
Synthesis and Fungicidal Activities of [2-(2,5-Dimethylphenoxymethyl)-a-methoxyiminobenzyl]-isoxazole Derivatives
A series of [2-(2,5-dimethylphenoxymethyl)-a-methoxyiminobenzyl]isoxazole derivatives were synthesized and their fungicidal activities against crop diseases were assessed. Our studies of the structure activity relationships revealed the fungicidal activities against cucumber powdery mildew and wheat powdery mildew were the strongest when the isoxazole moiety was comprised of 4,5-dihydro-3-isoxazolyl, 3-isoxazolyl and 3-methyl-5-isoxazolyl groups. Of the two geometrical isomers at the oxime moiety, the E-isomers of non-substituted isoxazole derivatives were more active than the Z-isomers. On the other hand, the Z-isomers of methyl-substituted isoxazole derivatives were more active than the E-isomers Further, [2-(2,5-dimethylphenoxymethyl)-a-methoxyiminobenzyl]isoxazole derivatives exhibited highly potent respiratory inhibition.
Key words: [2-(2,5-dimethylphenoxymethyl)-a-methoxyiminobenzyl]isoxazole derivatives, alkoxy-iminoacetamide derivatives, (E)-2-(2,5-dimethylphenoxymethyl)phenyl-2-methoxyimino-N-methyl-acetamide, fungicidal activity, powdery mildew.
Photosynthetic Electron Transport Inhibitory Activity of 2-Aralkylamino-4-methyl-6-trifluoromethyl-1,3,5-triazine Derivatives
A series of 2-aralkylamino-1,3,5-triazine derivatives was synthesized and their photosynthetic electron transport (PET) inhibitory activity was evaluated. Investigation on the relationship between PET inhibitory activity and substituents on the triazine ring revealed that 2-benzylamino-4-methyl-6-trifluoromethyl-1,3,5-triazine exhibited a highly PET inhibitory activity. Furthermore, introduction of a halogen or a trifluoromethyl group at 3- or 4-position of the benzene ring enhanced PET inhibitory activity, exhibiting pI50=6.91-7.29. Their PET inhibition was about 10 times stronger than that of simazine. On the absolute configuration of chiral center in 2-methyl-4-(a-methylbenzylamino) 6-trifluoromethyl-1,3,5-triazine, (-)-enantiomer was around 100 times stronger than (+)-enantiomer. However, the PET inhibitory activity was decreased by N-alkylation of the benzylamino group in 2-benzylamiamino-4-methyl-6-trifluoromethyl-I,3,5-triazine.
Key words: photosynthetic electron transport, PET inhibitory activity, spinach thylakoids, 2-aralkylamino-I,3,5-triazines, 2-benzylamino-4-methyl-6-trifluoromethyl- I,3,5-triazines.
Effects of Nitenpyram on the Neuronal Nicotinic Acetylcholine Receptor-Channel in Rat Phaeochromocytoma PC12 Cells
Nitenpyram, (E)-N-(6-chloro-3-pyridylmethyl)-N-ethyl-N'-methyl-2-nitro-vinylidenediamine, is known to act on the nicotinic acetylcholine receptor-channel (AChR). We examined the effects of nitenpyram on the neuronal type of the nicotinic AChR in rat clonal phaeochromocytoma PC12 cells using a patch clamp technique to clarify the mechanisms of action at the single-channel level. Nitenpyram itself induced single-channel currents mediated by the neuronal nicotinic AChR. Co-application of ACh and nitenpyram opened the channels exhibiting the two conductance states. The proportion of main conductance levels was decreased and that of subconductance levels was increased in the presence of nitenpyram. The open time and closed time distribution, but not for the burst duration, for the main conductance state currents with co-application of ACh and nitenpyram were similar to those of ACh-induced current. These changes of single-channel kinetics result in a decrease in probability of openings of main conductance state currents explaining the effects of nitenpyram on the neuronal nicotinic AChR. The effects of nitenpyram on the acetylcholine-induced current are deemed directly responsible for the toxic actions in animals.
Key words: nitenpyram, nicotinic acetylcholine receptor, PC12 cell, patch clamp, single channel.
Synthesis and Fungicidal Activities of 3-(a-Alkoxyiminobenzyl)isoxazole Derivatives
A series of 3-(a-alkoxyiminobenzyl)isoxazole derivatives were synthesized and their fungicidal activities against crop diseases were assessed. Studies of the structure-activity relationships revealed the strongest fungicidal activity when the alkoxyimino moiety was substituted with a methyl group. When the position-2 of the benzene ring on the benzyl moiety was substituted with a phenoxymethyl group, a good fungicidal activity was obtained. Among the compounds examined, 3-[2-(2,5-dimethylphenoxymethyl)-a-methoxyiminobenzyl]isoxazole showed potent fungicidal activity against cucumber powdery mildew, wheat powdery mildew and wheat eye spot.
Key words: 3-(a-alkoxyiminobenzyl)isoxazole derivatives, alkoxyiminoacetamide derivatives, fungicidal activity, powdery mildew, eye spot.
Synthesis and Herbicidal Activity of New Oxazolidinedione Derivatives
A series of new 3-(substituted phenyl)-5-alkylidene-1,3-oxazolidine-2,4-dione derivatives was synthesized by reacting substituted phenyl isocyanates with 2-hydroxy-3-alkenoates prepared through an acid-catalyzed isomerization of 3,3-disubstituted glycidates, and their herbicidal activities against various weeds as well as the crop safeties were examined. The herbicidal activities of these oxazolidinedione derivatives were primarily influenced by the substituents on the phenyl group and by the structure of the alkylidene moiety. The compounds having a 2,4-dihalo-5-alkoxyphenyl moiety exhibited relatively higher herbicidal activities while the introduction of a long chain alkylidene group at the 5-position of the oxazolidine ring reduced the activity. The crop safety was found to be markedly affected by the substituent at the 5-position of the phenyl group and a cyclopentyloxy group seemed to be the most preferable one. Among the compounds synthesized, 3-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione (KPP-314) was selected as a promising paddy rice herbicide. In green-house pot tests, KPP-314 exhibited an excellent activity against annual lowland weeds by pre- and post-emergence soil treatments at 150 to 450 g a.i./ha with a wide safety margin between rice plant and Echinochloa oryzicola.
Key words: KPP-314, cyclic imide, Protox inhibitor, peroxidizing herbicide, rice, Echinochloa oryzicola.
Synthesis and Plant Growth-Regulating Activity of Novel N-Phthaloyl-L-threonines and Their Dehydrated Phthalimides
N-Phthaloyl-L-threonines (P-Thrs) and their dehydrated phthalimides (2-phthalimido-2-butenoic acids, P-BTEAs) were readily synthesized and showed a strong root growth-promoting activity for rice seedlings. Of the synthetic P-Thrs and P-BTEAs, (Z)-2-phthalimido-2-butenoic acid (P-BTEA), (Z)-2-(4-chlorophthalimido)-2-butenoic acid (4-CIP-BTEA) and (Z)-2-(3-fiuorophthalimido)-2-butenoic acid (3-FP-BTEA), in particular, had a strong root growth-promoting activity for rice seedlings. This activity at I x l0-4 M was 3.3- to 3.7-fold the control value. The root growth-promoting activities for rice seedlings of all the dehydrated phthalimides (P-BTEAs) were greater than those of the mother compounds (P-Thrs). For lettuce seedlings 4-CIP-BTEA and 4-MeP-BTEA alone had a weak root growth-promoting activity at I X l0-4 M. Some P-Thrs and BTEAs caused severe necrosis of lettuce seedling roots and hypocotyls at the high concentration of I X lO-3 M. Nitro-substituted Thrs and BTEAs with strong electron withdrawing group, however, have no root growth-promoting activity.
Key words: plant growth regulators, root growth-promoting activity, N-phthaloyl-L-threonine, 2-phthalimido-2-butenoic acids.
Effect of Imidacloprid on Virus Vector Laodelphax striatellus Fallen in Prevention of Rice Stripe
Key words: imidacloprid, insect vector control, Laodelphax striatellus, prevention of virus transmission.
Methods of Determination of Acetamiprid and Its Degradation Products in Soil by Gas Chromatography
Key words: parent methods, common moiety method, acetamiprid, GC, soil.
Changes in Microbial Community Structure in Soil Percolated with Pentachlorophenol with Reference to Respiratory Quinone Profile
Key words: pentachlorophenol, respiratory quinone profile, structure of microbial communities in soil, microbial diversity, bacteria, fungi, crystalviolet-tolerant bacteria.
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