Benzpyrimoxan: Design,synthesis, and biological activity of a novel insecticide

Benzpyrimoxan (5-(1,3-dioxan-2-yl)-4-{[4-(trifluoromethyl)phenyl]methoxy}pyrimidine, NNI-1501) was discovered as a novel insecticide structurally characterized by a pyrimidine derivative substituted with 1,3-dioxanyl and 4-trifluoromethylbenzyloxy groups. The compound showed remarkable activity against nymphs of rice planthoppers, including strains resistant to existing insecticides. Furthermore, benzpyrimoxan had low adverse effects on pollinators and beneficial arthropods. Because of these features, benzpyrimoxan is expected to be a suitable part of an integrated pest management strategy. In this report, the history of the discovery to reach benzpyrimoxan and details of the structure–activity relationships are described.     

Evaluation of chiral alpha-cyanoesters as general fluorescent substrates for screening enantioselective esterases

Esterases play a crucial role in industrial chemical synthesis, maintaining normal physiological metabolism and detoxifying exogenous ester-containing toxicants. To meet the rapidly increasing industrial need for all kinds of esterases, especially enantioselective esterases used to generate highly pure chiral compounds, general substrates are necessary for rapid screening, monitoring, purification, and characterization. In this study, general fluorescent substrates including phenolic derivatives and alpha-cyanoesters were evaluated for sensitivity in detecting esterases in buffer systems. Results with two different esterases and different incubation times suggested that the alpha-cyanoesters examined were significantly more sensitive at detecting esterases than the corresponding tested phenolic derivatives. More importantly, alpha-cyanoesters, containing a secondary alcohol, possess at least one chiral center; thus, they are tools to screen for enantioselective hydrolysis. Results indicated that the enantioselectivity of esterases toward general alpha-cyanoesters strongly depended on the esterase and the substrate, but the majority of esterases examined preferred S-isomers to their corresponding R-enantiomers. Most appealing was the very high enantioselectivity displayed in cytosolic esterases of the house fly. The potential utility of such esterases is discussed. In addition, the use of alpha-cyanoesters as chiral fluorescent substrates was demonstrated for monitoring in enantioselective esterases.     

Molecular cloning and expression analysis of double-stranded RNA-dependent protein kinase (PKR) in rock bream (Oplegnathus fasciatus)

We have cloned and characterized rock bream double-stranded RNA-dependent protein kinase (PKR), which is a key component of type I IFN inducible innate immune system. Full-length rock bream PKR cDNA consists of 2115 bp ORF encoding 704 amino acids, 124 bp 5′ UTR, and 529 bp 3′ UTR. Conserved domain analysis revealed that rock bream PKR contained two tandem dsRBM and kinase domain consisted of 11 kinase sub-motifs, which are characteristics found in other PKRs. Rock bream PKR was constitutively expressed in the spleen of rock bream and, upon injection of poly I:C, up-regulated not later than 12 h post injection and returned to baseline level at 48 h post injection. Although the eIF2α kinase activity of rock bream PKR was not examined in the present study, dsRNA inducible nature of rock bream PKR implies the possible important role of this gene in innate immune system of rock bream as suggested in zebrafish and flounder.     

Symbiotic bacterium modifies aphid body color

Color variation within populations of the pea aphid influences relative susceptibility to predators and parasites. We have discovered that infection with a facultative endosymbiont of the genus Rickettsiella changes the insects' body color from red to green in natural populations. Approximately 8% of pea aphids collected in Western Europe carried the Rickettsiella infection. The infection increased amounts of blue-green polycyclic quinones, whereas it had less of an effect on yellow-red carotenoid pigments. The effect of the endosymbiont on body color is expected to influence prey-predator interactions, as well as interactions with other endosymbionts.     

Effect of thin twine on gill net size-selectivity analyzed with the direct estimation method

ABSTRACT: To analyze the effect of thin twine on gill net size selectivity, a series of fishing experiments using gill nets of two twine thicknesses (no. 0.8 of 0.16 mm diameter and no. 3 of 0.28 mm diameter) and three nominal mesh sizes (41 mm, 46 mm and 51 mm) was conducted in outdoor water tanks containing a rainbow trout ( Oncorhynchus mykiss ) population of known size frequency. For nets of the same nominal mesh size, mesh openings of the no. 0.8 twine nets were approximately 2 mm larger than those of the no. 3 twine nets. The effects of both mesh opening and twine thickness are combined in the conventional analysis with the selectivity curve against fish length. Selectivity against the ratio of fish girth to mesh perimeter was calculated to avoid the direct effect of changes in mesh openings due to twine diameter at the same nominal mesh size. Results demonstrated that the thinner twine gill net was more likely to capture rainbow trout of smaller girth than the mesh perimeter. Fish with girths smaller than the mesh perimeter were often retained by the net with its body tangled by the thinner twine, possibly due to the increased flexibility of the thinner twine.     

Necrotic hepatitis due to Clostridium perfringens infection in newly hatched broiler chicks

Multiple necrotic hepatitis lesions of 5 newly hatched broiler chicks in three flocks derived from two hatcheries were examined pathologically. The livers were brittle, and multiple yellowish or green foci were scattered on the surface and cut surface. The main histological finding was well demarcated multi-focal necrosis in the liver. Many Gram-positive large bacilli that reacted positively with polyclonal anti-Clostridium perfringens serum were observed in necrotic areas.