Single oral β-cryptoxanthin administration increases its serum concentration and enhances peripheral blood neutrophil function in Holstein cattle

We investigated the effect of oral administration of β-cryptoxanthin (β-CRX) on its serum concentration and peripheral neutrophil functions by the chemiluminescence (CL) response in Holstein cattle. A single oral administration of β-CRX was performed for serum β-CRX concentration (0, 0.05, 0.1, or 0.2 mg/kg body weight [BW]) and for peak CL response of peripheral neutrophils (0.2 mg/kg BW). The serum β-CRX concentration was peaked on 2 days after, similar to peak CL response on 3 days after β-CRX administration. Therefore, a single oral administration of β-CRX (0.2 mg/kg BW) induces higher serum concentration and concurrently enhances bactericidal ability of peripheral neutrophils in Holstein cattle.     

Structural Effects of N-Arylcarbamoylpyrazolines on Calcium Uptake in Rat Brain Synaptosomes

N-Arylcarbamoylpyrazolines with various substituents at the para position of the carbamoyl benzene ring inhibited ATP-dependent Ca²⁺-uptake in synaptosomes prepared from the rat brain. The activity of these compounds was evaluated as log(1/I₅₀), the reciprocal logarithm of half inhibitory concentration, I₅₀ (m ), from the concentration–response curve for the inhibition of Ca²⁺-uptake. Among the compounds tested, methyl 3-(4-chlorophenyl)-4-methyl-1-[N-(4-trifluoromethylphenyl)carbamoyl]-2-pyrazoline-4-carboxylate was the most potent, the I₅₀ value of which as 9·12×10⁻⁷ m . Variations in the activity in terms of log(1/I₅₀) were quantitatively analysed using a substituent parameter, showing that the higher the electron-withdrawing effect of the substituent, the higher was the activity. The substituent effects were similar to those on insecticidal activity against the Americal cockroach. The higher the inhibitory activity against Ca²⁺ uptake, the higher seemed to be the insecticidal activity. Methyl(4S) - 3 - (4 - chlorophenyl) - 4 - methyl - 1 - [N - (4 - chlorophenyl)carbamoyl] - 2 - pyrazoline -4-carboxylate had higher inhibitory activity against Ca²⁺-uptake and higher in-secticidal activity than the R-isomer, but the difference was greater in theCa²⁺-uptake system.     

Quantitative structure-activity analysis of larvicidal 1-(substituted benzoyl)-2-benzoyl-1-tert-butylhydrazines against Chilo suppressalis

The larvicidal activity of a number of 1-(substituted benzoyl)-2-benzoyl–1 -ten-butylhydrazines against the rice stem borer (Chilo suppressalis Walk.) was measured. Variations in the activity were examined quantitatively using physico-chemical substituent and molecular parameters and regression analysis. The results indicated that the molecular hydrophobicity and the electron-withdrawing inductive/ field effect of ontho substituents are favourable to larvicidal activity. The bulkiness of substituents at the meta and para positions was unfavourable to activity, substitution at the para position being more unfavourable than that at the meta position in terms of van der Waals' volume. The 2,3–, 2,5- and 2,6-disubstitution patterns were also unfavourable to activity. Reductions in larvicidal activity caused by the 2,6-,- 2,3,5- and 2,3,4,5-substitutions were greater than those induced by the 2,3- and 2,5-disubstitutions. When the sum of contributions from favourable effects is greater than that from unfavourable effects, the larvicidal activity is expected to be superior to that of the unsubstituted compound.     

Quantitative structure—activity studies of insect growth regulators. XI. Stimulation and inhibition of N-acetylglucosamine incorporation in a cultured integument system by substituted N-tert-butyl-N,N′-dibenzoylhydrazines

The ability to stimulate N-acetylglucosamine (GluNAc) incorporation in-vitro of a number of N-tert-butyl-N,N′-dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in-vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in-vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in-vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle.     

Structural effects of dinotefuran and analogues in insecticidal and neural activities

The insecticidal potencies of dinotefuran and analogues against the adult male American cockroach, Periplaneta americana (L) were measured by injection with or without metabolic inhibitors. The potency of dinotefuran was close to those of clothianidin and imidacloprid under the conditions used. The nerve-excitatory and nerve-blocking activities were measured with central nerve cords of P americana. The nerve-excitatory activity of dinotefuran was lower than that of imidacloprid, but was comparable with that of clothianidin. The nerve-blocking activity of dinotefuran was comparable with that of imidacloprid and slightly higher than that of clothianidin. Quantitative analyses showed that variations in the insecticidal activity were better correlated with variations in the nerve-blocking activity than with those in the nerve-excitatory activity when the contribution of the hydrophobic factor was allowed for.     

Quantitative structure-activity studies of substituted benzyl chrysanthemates: 7. Relationship between induction of repetitive discharges and effects on the action potential

The effects of substituted benzyl (1R)-trans-chrysanthemates and related compounds on the action potential of the crayfish giant axon were investigated using an intracellular microelectrode. The effects are broadly classified into three types: deceleration of the falling-phase of the action potential (type A), elevation of the depolarizing after-potential (type B), and the combination type (type C). The potency of the type A compounds to decelerate the rate of the falling-phase was determined in terms of the concentration required for reducing the rate to a specified degree. This potency was shown to correlate with the potency to induce repetitive discharges in the cockroach central nerve cord in terms of minimum effective concentration, which was determined previously. The potency of the types B and C compounds to elevate the after-potential was, however, not related directly with the cockroach nerve repetitive activity. The elevation of the after-potential is one of the critical factors but other effects such as a depolarization of the resting potential may be involved in determining the repetitive activity.     

Insecticidal and neuroblocking potencies of variants of the imidazolidine moiety of imidacloprid-related neonicotinoids and the relationship to partition coefficient and charge density on the pharmacophore

The pharmacophore of the neonicotinoid insecticide imidacloprid, nitroiminoimidazolidine, was modified to heterocycles such as thiazolidine, pyrrolidine, dihydroimidazole, dihydrothiazole, and pyridone conjugated to nitroimine (=NNO2) or nitromethylene (=CHNO2). Their 6-chloro-3-pyridylmethyl or 5-chloro-3-thiazolylmethyl derivatives were examined for insecticidal activity against the American cockroach by injection and for neuroblocking activity using the cockroach ganglion. Most of the compounds having the neonicotinoidal pharmacophore exhibited insecticidal activity at the nanomolar level, which was enhanced in the presence of synergists, and high neuroblocking activity at the micromolar level. Quantitative analysis for the compounds showed that the neuroblocking potency is proportional both to the Mulliken charge on the nitro oxygen atom and to the partition coefficient log P value. The equation for the insecticidal versus neuroblocking potencies indicated that both potencies are related proportionally with each other when the other factors are the same.     

Applicability of effective medium theory to wood density measurements using terahertz time-domain spectroscopy

The use of an effective medium theory is important when accurately measuring wood density using millimeter and terahertz wave techniques. To confirm the applicability of this theory to the evaluation of wood density, the relative permittivity and dielectric loss of oven-dry flat-sawn specimens of 11 different wood species were measured in a frequency range of 0.15–1.2 THz using a transmission measurement system for terahertz time-domain spectroscopy. A mixture model based on the effective medium theory well explained the density dependence of relative permittivity over the entire frequency range, while it did not fully explain that of dielectric loss, especially for higher frequencies. This indicates that wood scatters the terahertz wave with a wavelength close to the transverse sectional dimensions of the pores in wood in the same way as Mie scattering. It was found from the dielectric loss spectrum of wood substance that the frequency around 0.23 THz was preferable for the nondestructive evaluation of wood.     

Effect of pore conformation on dielectric anisotropy of oven-dry wood evaluated using terahertz time-domain spectroscopy and eigenvalue problems for two-dimensional photonic crystals

To clarify the effect of pore conformation on the dielectric anisotropy of wood, the relative permittivity along the longitudinal and tangential axes of flat-sawn oven-dry specimens of 12 different wood species was measured using terahertz time-domain transmission spectroscopy and compared with the values calculated using the eigenvalue problem for two-dimensional photonic crystals. The measured dielectric anisotropy, which is the ratio of the relative permittivity along longitudinal axis to that along the tangential axis, was well explained by the calculated value. It was concluded that the ratio of tangential to radial widths of wood pores affects the relative permittivity along the tangential axis, and that the dielectric anisotropy decreased with an increase in the ratio. This discussion can also be applied to the relative permittivity in frequencies below 0.15 THz. These findings show promise as a new method for evaluating the porous structure of wood.