A facile synthesis of Tyrian purple based on a biosynthetic pathway

ABSTRACT: A facile synthesis of Tyrian purple, a valuable purple dye derived from gastropod mollusks in ancient times, has been accomplished. Tyrian purple, 6,6'-dibromoindigo, was easily obtained by three steps of reactions from the commercially available 6-bromoindole, on the basis of a biosynthetic pathway of indigo and biological precursors of the purple. Iodination of 6-bromoindole, followed by acetoxylation with silver acetate in acetic acid, afforded 6-bromo-3-acetoxyindole, whose alkaline hydrolysis accompanying air oxidation produced Tyrian purple.     

Is yield enhancement by CO2 enrichment greater in genotypes with a higher capacity for nitrogen fixation?

Yield responsiveness to elevated CO₂ concentration [CO₂] was previously found to be greater when nitrogen (N) was supplied in adequate amounts; however, it remains unclear whether genotypic differences in N₂-fixing capacity affect yield responsiveness in soybean. We tested the hypothesis that yield responsiveness to elevated [CO₂] in soybean is greater in a genotype with a higher capacity for N₂ fixation. We used three near-isogenic genotypes with contrasting nodulation capacities: super-nodulating, normally nodulating and non-nodulating genotypes. Plants were subjected to two levels of [CO₂] (ambient or elevated: ambient + 200 μmol mol⁻¹) and two temperature regimes (low or high: low + ca. 4-5 °C) using temperature gradient chambers. The super-nodulating genotype exhibited a higher N content in leaves, regardless of [CO₂] and temperature. Photosynthetic rates were enhanced by CO₂ enrichment at earlier growth stages, but not at later growth stages, regardless of genotype. This photosynthetic acclimation was reflected in biomass production in all the genotypes examined. Yield responsiveness to elevated [CO₂] was greater in the nodulating genotypes than in the non-nodulating genotype, but the genotypic differences were obscured between the normally nodulating and super-nodulating genotype, thus our hypothesis was not fully verified.     

Organic-inorganic hybrid zeolites containing organic frameworks

Organic-inorganic hybrid zeolite materials containing an organic framework have been synthesized by partially superseding a lattice oxygen atom by a methylene group. The use of methylene-bridged organosilane as a silicon source gives zeolite materials containing an organic group as lattice (ZOL), with several zeolitic phases such as the MFI and the LTA structures. Through various characterization methods, the presence of methylene frameworks (Si-CH2-Si) that replace siloxane bonds (Si-O-Si) has been verified, although the Si-C bonds are partly cleaved to give rise to terminal methyl groups. The shape-selective lipophilicity of a ZOL material indicates that it is not a physical mixture of conventional zeolite and amorphous organic-containing material but contains a genuine organic-inorganic hybrid zeolite.     

Effects of feeding time on approaching behavior to food odor in goldfish

ABSTRACT:   Effects of feeding time on approaching behavior to food odor in goldfish Carassius auratus were examined using the Y-maze flow-through system to test whether the behavior differed according to feeding time and experimental time. Fish were fed at 08.00, 12.00 or 16.00 hours once a day or three times (08.00, 12.00 and 16.00 hours) a day for at least 3 weeks under a natural photoperiod, and at 22 ± 2°C, preference reactions to food odor were tested at 08.00, 10.00, 12.00, 14.00 and 16.00 hours. The fish fed once a day showed significant positive approaching behavior only at the time when they were normally fed. The fish fed three times a day showed no significant positive approaching behavior. These results suggest that goldfish can remember when food is available and/or that there exists a mechanism to inhibit approaching behavior when food is not available.     

Bacteriolytic activity and growth of marine isolates of labyrinthulids on dead bacterial cells

ABSTRACT:   Thirteen strains of labyrinthulids were isolated from the coastal area of Kagoshima Bay, Kagoshima Prefecture, Japan and from Batan Bay, Panay Island, the Philippines by using diatom double-layer agar plates. The cells of labyrinthulid isolates grew axenically on the dead bacterial cells and extract plus egg yolk agar medium (NSBEY agar). Three representative isolates were demonstrated to belong to the labyrinthulid phylogenetic group (LPG) based on 18S  rDNA sequence analysis. As bacteriolytic activity of labyrinthulid isolates was examined, it was found that they could lyze only the dead cells of gram-negative bacteria and not those of gram-positive bacteria during incubation in both agar and liquid media. The optimum temperature range for bacteriolysis was 25–31°C. Orange carotenoid pigment was accumulated during the stationary growth phase of strain 00-Bat-05, Philippine isolate, cultured in an L-shaped tube containing a bacterial dead cell suspension. Concomitant rapid cell movement of developing zoospores was observed.     

Antitumor activity of Toxoplasma lysate antigen against methylcholanthrene-induced tumor-bearing rats.

Growth of the tumor autoinduced by 20-methylcholanthrene (MC) in rats was inhibited after administration of Toxoplasma lysate antigen (TLA). The antitumor activity of TLA was most obvious in the early stage of tumoral growth. When TLA was administered to rats before the appearance of tumour, tumor formation was delayed slightly. Histopathological studies revealed dense growths of spindle tumor cells in untreated control rat, while enlarged central necrosis with the infiltration of lymphocytes and neutrophils was apparent in TLA-treated rats. According to the immunohistological examination of tumor tissue with anti-Thy-1 antibody, the rats treated with TLA showed large Thy-1 positive granular cells, whereas the untreated rats indicated only a few small Thy-1 positive cells. These observations indicate that TLA is a useful modifier of biological responses to MC-induced tumors.     

Actions of glucocorticoid and their regulatory mechanisms in the ovary

Glucocorticoid (G) directly modulates ovarian functions through binding to G receptor. The actions of G are both agonistic and antagonistic depending on the developmental stage of follicles and corpora lutea (CL). During follicular maturation, G suppresses follicular differentiation by downregulating expression of P450 aromatase and luteinizing hormone (LH) receptor in granulosa cells. During ovulation, G protects the ovulatory follicle from inflammatory damage and promotes luteinization, ensuring a smooth transition of the follicle to CL. Throughout life the ovary is exposed to periodic and sporadic waves of G. The Ovary appears to cope with this situation by locally modulating levels of active G. The primary regulatory mechanism consists of two isoforms of 11β‐hydroxysteroid dehydrogenase (11βHSD) that catalyze conversion between active and inactive G. During follicular maturation the levels of active G are suppressed by the dehydrogenase activity of 11βHSD, whereas during the ovulatory process, levels of active G are further increased by the oxo‐reductase activity of 11βHSD. The expression of these enzymes is under the control of gonadotrpins and local regulatory factors such as cytokines, allowing the mechanism to act in coordination with major reproductive events. Thus the G system is an integral part of ovarian physiology, which ensures that the ovary experiences only beneficial effects of G.     

An Endophytic Actinomycete, Streptomyces sp. AOK-30, Isolated from Mountain Laurel and Its Antifungal Activity

To survey endophytic actinomycetes as potential biocontrol agents against fungal diseases of mountain laurel, young plants of mountain laurel (Kalmia latifolia L.) were used as an isolation source. From a total of 73 actinomycetes isolates obtained from leaves, stems and roots of test plants, Streptomyces sp. AOK-30 was selected, because i) it had a broad and intense antimicrobial spectrum against various yeasts and fungal pathogens of Ericaceae, ii) it grew on the multiplication and rooting media for tissue culture for this plant, and iii) the tissue-cultured seedlings that had been treated with this isolate became resistant to Pestalotia disease without any adverse growth effects such as malformation, dwarfing, discolorization and defoliation. This isolate was identified as Streptomyces sp., based on cultural, physiological and morphological characteristics. The present results indicate that isolate AOK-30 is a potential biocontrol agent against diseases of mountain laurel. Received 10 September 2002/ Accepted in revised form 22 November 2002     

Epidemiological survey of Babesia gibsoni infection in dogs in Japan by enzyme-linked immunosorbent assay using B. gibsoni thrombospondin-related adhesive protein antigen

A nationwide epidemiological survey of Babesia gibsoni infection in non-fighting dogs was conducted using an improved ELISA with recombinant B. gibsoni thrombospondin-related adhesive protein (BgTRAP). A total of 1206 dogs from 27 prefectures were examined and 128 (10.6%) tested positive. In the eastern part of Japan, 39 dogs out of the 559 (7.0%) examined were positive, while 89 dogs out of 647 (13.8%) tested positive in the western part of Japan. Although the percentage of dogs that tested positive was significantly (p=0.0001) lower in the eastern part compared to the western part of Japan, overall these results indicate that B. gibsoni infection of dogs has a widespread geographic distribution throughout the country. A history of tick infestation was identified as a significant risk factor for B. gibsoni infection (p=0.0091), while sex (p=0.9411), age (p=0.0920) and breed (p=0.0549) of dogs were not statistically significant risk factors. These results indicate that tick infestation is the most dominant risk factor for B. gibsoni infection of non-fighting dogs in Japan and suggest that other B. gibsoni transmission routes, such as fighting and transplacental transmission, may be less important.     

Serological survey of Neospora caninum infection among dogs in Japan through species-specific ELISA

A seroepidemiological survey of Neospora caninum infection among dogs in Japan was conducted using species-specific enzyme-linked immunosorbent assay with recombinant surface antigen (Nc-SAG1t). Among 1,206 dogs examined, 126 dogs (10.4%) from 30 prefectures from Hokkaido to Okinawa were positive to N. caninum infections, which were more frequently detected in females than males. Siberian Huskies showed the highest positive rate compared with the other breeds. Dogs with pyometra and diabetes mellitus showed the higher positive rates than dogs with other diseases or without diseases.