Identification of novel genes expressed highly and selectively in the corpora allata of the silkworm,Bombyx mori (Lepidoptera: Bombycidae)

Applied Entomology and Zoology - Juvenile hormone (JH) has crucial roles in insect physiology, including development, reproduction, and polyphenism. JH is synthesized in the corpora allata (CA)...     

Lead optimization of 5-amino-6-(2,2-dimethyl-5-oxo-4-phenylpiperazin-1-yl)-4-hydroxyhexanamides to reduce a cardiac safety issue: Discovery of DS-8108b,an orally active renin inhibitor

With the aim to address an undesired cardiac issue observed with our related compound in the recently disclosed novel series of renin inhibitors, further chemical modifications of this series were performed. Extensive structure–activity relationships studies as well as in vivo cardiac studies using the electrophysiology rat model led to the discovery of clinical candidate trans-adamantan-1-ol analogue 56 (DS-8108b) as a potent renin inhibitor with reduced potential cardiac risk. Oral administration of single doses of 3 and 10 mg/kg of 56 in cynomolgus monkeys pre-treated with furosemide led to significant reduction of mean arterial blood pressure for more than 12 h.     

Effects of Chemical Agents on Radiation Inactivation of Streptomyces Protease in Aqueous System

Inactivation of crystalline enzyme, Streptomyces protease G, by γ-ray irradiation in an aqueous system has been investigated. It is indicated that inactivation of the enzyme is attributable mainly to the indirect action of radiation. The inactivation curve is exponential and the G-value for enzyme inactivation is calculated as 0.1 at an enzyme concentration of 1×10^?5m, which is not influenced by varying pH. Effects of various other solutes on radiation inactivation have been also studied. Halogen ions, especially iodine ion, and nitrite ion are most protective among various inorganic anions examined, and alkali metal and alkali earth metal cations are ineffective. Among various organic compounds examined, sulfur-containg compounds and unsaturated compounds are generally effective for protection of enzyme activity against radiation damages. The protective effect of benzene is enhanced by the substitution of electron donating groups. Chloroform and chloral are found to act as a synergist for irradiation inactivation.     

Aroma Constituents of Roasted Coconut

The volatile components of roasted and unroasted dried coconut shreds, isolated by steam distillation, were analyzed by GC and GC-MS. Seventeen compounds were identified from the unroasted coconut, and nine of them were newly identified in coconut meat aroma. Saturated delta-C₈, C₁₀, and C₁₂ lactones were determined as the main components giving the characteristic mild, sweet, and pleasant coconut flavor. The roasted coconut gave the strong characteristic sweet and nutty aroma, and the GC-MS indicated the saturated delta-lactones as main components, and six pyrazines, two furans, and two pyrroles also found seemed to contribute greatly to the nut-like aroma of roasted coconut. The defatted and roasted meal gave a strong nut-like and burnt odor, but not the characteristic sweet aroma. A large increase in pyrazines and other Maillard reaction products and an absence of lactones and fatty acid esters were observed in the volatiles of the roasted-defatted coconut meal.     

Modification of Combined Effect of Radiation and Sodium Chloride on Microorganisms by Chemical Agents during Irradiation

Effects of various chemical agents on the synergistic action of NaCl to the radiation inactivation of bacteria and yeast were studied. The remarkable modification of the radiation lethal effect by some reagents is considered to be a strong evidence for an indirect nature of NaCl synergistic action during irradiation. Most of these modification effects were restricted to the actions during irradiation, supporting the free radical hypothesis in which the short-life active species formed by radiation were considered to attack bacterial cells. Furthermore, pre-irradiation effects under various conditions suggest that the enhancement of radiation lethal effect by NaCl may involve the intracellular events.     

Effect of Irradiation on Microorganisms in a Nuclear Reactor

The effects of irradiation in the JRR-1 (Japan Research Reactor No. 1, a homogeneous light water nuclear reactor; max. power, 50 KW) on microorganisms such as bacterial and fungal spores and yeast cells were investigated in comparison with those of ⁶⁰Co gamma radiation. As far as the lethal effect was concerned the dose rate of radiation in the experimental hole No. 16 of the JRR-1 was equivalent to 3.0×l0⁶~3.4×l0⁶ r/hr with ⁶⁰Co gamma radiation, and a ratio of the neutron effect to the gamma radiation effect on microorganisms in this hole was estimated to be approximately 3~5.4. The results different from those with gamma radiation were obtained in experiments such as post-NaCl treatment and spore germination. The considerable contribution of fast neutrons to the total biological effect of neutrons, in comparison with the thermal neutron effect, could be presumed from the microbiological experiments with the help of physical and chemical data. Morphological changes in post-irradiation growth were observed by means of phase contrast microscopy. No specific aftereffect was found.     

Studies on γ-Radiolysis of Sulfur Containing Amino Acids

In connection with flavor deterioration accompanied by food irradiation, the effect of γ-irradiation on sulfoxide amino acids in air free aqueous system was investigated. The major radiolysis products from S-n-propyl-l-cysteine sulfoxide (PCSO) were alanine, cysteic acid, dipropyl disulfide, etc., and from S-allyl-l-cysteine sulfoxide (ACSO) were S-allyl-l-cysteine, cystine, cysteic acid, etc., which were isolated chromatographycally and identified by using IR and mass spectrometry. The sulfoxide in ACSO was more easily reduced to sulfide than that of in PCSO, and the bond of S-C (β-carbon in alanine moiety) in ACSO was difficult to cleave. These differences observed between PCSO and ACSO in the radiolysis products and their yields indicate that the radiolysis degradation is considerably influenced by the structure of alkyl group. From the experiments with N₂O or KBr addition during irradiation, principal roles of the active species in irradiated water in the degradation processes were partly elucidated.     

Mutagen Formation in the Reaction of Nitrite with the Food Components Analogous to Sorbic Acid

Mutagen formation by the reaction of sodium nitrite with some sorbic acid analogs was investigated by using the microbial mutagenicity tests (rec-assay and Ames test) together with chemical examination using TLC, and it became clear that the conjugated dienoic carbonyl structure is essential for mutagen formation by the reaction with nitrite By a large scale reaction of sodium nitrite with sorbic acid methyl ester, 5-nitro-2,4-hexadienoic acid methyl ester and ethylnitrohc acid were isolated and identified as the mam mutagens The results led to the assumption that a nitro group adjacent to the double bond is an important factor to develop mutagenicity     

Metabolism of Steviol and Its Derivatives by Gibberella fujikuroi

Steviol (ent-13-hydroxykaur-16-en-19-oic acid)* is metabolized by Gibberella fujikuroi in the presence of inhibitors of gibberellin biosynthesis, such as quaternary ammonium salt-type growth retardants, to afford 7β-Miydroxy- and 6β,7β-dihydroxysteviol, gibberelhns A₁, A₁₈, A₁₉, A₅₃ and 7β,13-dihydroxykaurenolide. Steviol acetate (ent-13-acetoxykaur-16-en-19-oic acid) is also metabolized to the 6β,7β-dihydroxy-derivative and to the 13-acetyl derivatives of gibberellins A₁₇ and A₂₀ and steviol methyl ester (methyl ent-13-hydroxykaur-16-en-19-oate) into the monohydroxy-, dihydroxy- and hydroxyoxo-derivatives. These results indicate a low substrate specificity of the enzymes in the fungus and provide a useful preparative methodology of several important plant gibberellins carrying the 13-hydroxyl group.     

The After Effect of Irradiated Halogenophenol Solutions on the Viability of Escherichia coli

Gamma irradiation has been found to induce a remarkable bactericidal activity in an aqueous soltion of p-bromophenol even at the non-toxic lower concentrations, but not in a crystalline form or under a frozen state. Effects of concentration of reagents, temperature, pH, radiation dose, oxygen and some additives during irradiation on the radiation induction of bactericidal activity in the p-bromophenol solution were investigated. The results suggest that the induced activity is attributable to some long-life products, formed as a result of radiolysis of p-bromophenol and in coupling with radiolysis of water. The processes of formation and destruction of such bactericidal factor(s) were considerably influenced by several conditions during irradiation. Based on the experimental results, relationship between radiolysis process and induction of bactericidal activity was discussed.