A new pyrethroid-type ester with strong knockdown activity

Thirteen pyrethroid-type esters of substituted 1(or 3)-hydroxymethylimidazolidine-2, 4-dione were synthesised and their knockdown activities against houseflies, mosquitoes and cockroaches were examined. Knockdown activities of 2,4-dioxo-1-prop-2-ynylimidazolidin-3-ylmethyl esters in oil solutions were higher than those of known knockdown pyrethroids; three of the compounds also possessed strong knockdown and flushing-out activities against cockroaches.     

Administration of two oils rich in n-3 long-chain polyunsaturated fatty acids to rat pups of dams fed a diet high in fat and low in n-3 polyunsaturated fatty acids

Long-chain polyunsaturated fatty acids (LCPUFA) with 20 or 22 carbons are considered important to the development of infants and sometimes added to infant formulae. In this study, two characteristic sources of n-3 LCPUFA (fish oil and microalgal oil) were orally administrated to rat pups of mildly n-3 PUFA — deficient dams to compare the consequences of the administration. The milk from the dams fed a n-3 PUFA — restricted diet contained less n-3 LCPUFA than that of the dams fed a control diet. Pups were administered 1 mg/g weight of the test oil at the age of 5–7 days. At the age of 7 days, they were sacrificed before or after the administration and fatty acid compositions of the stomach and serum lipid were studied. The administration changed docosahexaenoic acid (DHA; 22:6n−3) levels in the stomach contents and serum lipids with time. Eicosapentaenoic acid (EPA; 20:5n−3) levels increased immediately after the administration of fish oil. The administration of microalgal oil also affected the serum lipid EPA level, in spite of a lack of EPA. In this study, both oils effectively supplemented DHA. Fish oil returned the serum EPA level close to the control value while microalgae oil had little effect.     

Determination of nitrotyrosine by HPLC-ECD and its application

3-nitrotyrosine, a product of tyrosine nitration, is a useful indicator of oxidative damage. We modified the previously reported HPLC-electrochemical detection (ECD) method: specifically, a through-type porous carbon electrode was used as a reducing electrode instead of the mercury-gold amalgam electrode, because the response of the latter changes over time. A combination of reverse-phase HPLC and electrochemical detector passed through -800 mV reduction potential and subsequently under +250 mV oxidation potential allows measurement of 3-nitrotyrosine. The detection limit of this assay was less than 10 fmol. In mice to which lipopolysaccharide (LPS) was administered intraperitoneally, plasma 3-nitrotyrosine levels were elevated, corresponding to LPS dosage. These findings suggest that the improved HPLC-ECD method can be used as a specific and sensitive assay of biological 3-nitrotyrosine and can be applied clinically.     

2-arylalkanoates,a new group of synthetic pyrethroid esters not containing cyclopropanecarboxylates

Although structure modifications of natural pyrethrin constituents have disclosed a variety of potent synthetic analogues, all known examples are cyclopropanecarboxylate esters, a grouping that appeared to be essential for insecticidal activity. Some new substituted 2-phenylalkanoates, whose biological activities are of a similar nature and potency to those of conventional pyrethroids, are now reported. 5-Benzyl-3-furylmethyl and 3-phenoxybenzyl 3-methyl-2-phenylbutyrates and their analogues are potent insecticides. Activity is increased on the introduction of appropriate groups into the 3 and/or 4-positions of the aryl ring and the (S)-2-phenylalkanoates are far more active than their (R)-enantiomorphs. Structure/activity relationships are compared with those for conventional pyrethroids. Some of the new series compare favourably with typical insecticides in tests against Musca domestica, Spodoptera litura and Plutella xylostella.     

Estimation Models for the Morbidity of the Horses Infected with Equine Influenza Virus

Estimation formulas for the morbidity of horses infected with equine influenza virus by linear regression, logistic regression and probit transformation were developed, using data from the outbreak at the Sha Tin Racing Track in Hong Kong in 1992. Using these formulas, we estimated the equine influenza virus morbidity rates at training centers belonging to the Japan Racing Association (JRA) in October 1997 and in October 1998. In 1998 JRA started a new vaccination program, and every horse must now be vaccinated twice per year. At that time, the vaccine included two US lineage virus strains, the A/equine/Kentucky/81 strain and the A/equine/La Plata/93 (LP93) strain, against equine type-2 influenza viruses; it did not include any EU lineage virus strains, such as A/equine/Suffolk/89 (SF89). Comparing the geometric mean (GM) values of hemagglutination inhibition (HI) titers between the LP93 strain and the SF89 strain in 1997 and in 1998, they both rose significantly at every age (p<0.05) by Wilcoxon test. Calculations by the simulation models show the morbidity rates for LP93 diminished from 0.439 (linear), 0.423 (logistic) and 0.431 (probit) to 0.276 (linear), 0.265 (logistic) and 0.271 (probit), respectively. On the other hand, the estimated morbidity rates for SF89 diminished only slightly from 0.954 (linear), 0.932 (logistic) and 0.944 (probit) to 0.946 (linear), 0.914 (logistic) and 0.927 (probit), respectively. Our simulation models could estimate the effect of the vaccine on each of the equine virus strains represented by the morbidity of infected horses. Thus, they are useful for vaccine evaluation.     

Beneficial effects of dietary fish-oil-derived monounsaturated fatty acids on metabolic syndrome risk factors and insulin resistance in mice

The aim of this study was to elucidate the effect of fish-oil-derived monounsaturated fatty acids (MUFAs) containing large amounts of C20:1 and C22:1 isomers on metabolic disorders in mice. Male C57BL/6J mice were fed a 32% lard diet (control) or a 27% lard plus 5% saury-oil-derived MUFA diet for 6 weeks. Dietary MUFA improved insulin resistance and alleviated metabolic syndrome risk factors by reducing blood glucose and lipids. These favorable changes may be attributed to an improved adipocytokine profile. MUFA ingestion resulted in favorable changes in mRNA expression of genes involved in glucose/lipid metabolism (SCD-1, CPT1a, UCPs, and CS) as well as inflammation (MAC1, MMP3, and SAA3) and alterations in fatty acid composition. Our data suggest that marine MUFA improved glucose/lipid homeostasis and hindered the development of metabolic syndrome in obese mice.     

Effect of oil droplet sizes of oil-in-water emulsion on the taste impressions of added tastants

ABSTRACT:   By conducing organoleptic analysis, the authors investigated the effect of oil droplet size on human preference to the taste of oil-in-water (o/w) emulsions to which several tastants were added. Two singly dispersed o/w emulsions, different in oil droplet sizes, consisting of 10% triacilglycerol purified from tuna, sardine or soybean oil, 0.5% emulsifier and water were prepared by ceramic membrane filtration. Organoleptic analysis showed that the impressions of sweetness, bitterness and umami, which were developed by addition of certain taste substances, were different between o/w emulsions with different oil droplet sizes. The results of two-bottle choice tests, which were carried out using olfactory-blocked mice, showed that o/w emulsions with 1.00-µm droplets, with added sweet or bitter substances, were preferred to emulsion with 5.50-µm droplets. These results suggest that the droplet size of o/w emulsion remarkably influences certain taste impressions created by added taste substances.     

A new pyrethroid of high insecticidal activity

New pyrethroids containing heterocyclic rings in the alcohol moieties were synthesised and their insecticidal activities were studied. Of these new pyrethroids, 3-benzylpyrrol-1-ylmethyl (1RS-cis, trans-3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate was found to be the most effective, having higher activity than permethrin against Musca domestica by a topical application method. In addition, para-substituted analogues of the 3-benzylpyrrol-1-ylmethyl ester were also synthesised to study the substituent effects on insecticidal activities; the residual effects of these compounds against Blattella germanica were also examined.