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101.
Previous studies showed that 2-ethyl-3-methoxycarbonyl-1-(p-tolylcarbamoyl) isourea acts as a potent GA3-synergist in stimulating shoot growth of rice seedlings. Studies with several structurally related compounds show that the alkoxycarbonylcarbamoyl-isourea or -isothiourea skeleton is required for biological activity. Any chemical deletion from this skeleton causes complete loss of activity. From present and previous data it seems that alkoxycarbonylcarbamoyl-isourea or -isothiourea is converted by intramolecular cyclization in the rice seedlings into the corresponding triazinone that serves as the active form.Part 9 in the series Plant Growth-regulating Activities of Isourea Derivatives and Related Compounds; for Part 8 seeReferences, Ogawa et al. (1980b) 相似文献
102.
Previous studies showed that 2-ethyl-3-methoxycarbonyl-1-(p-tolylcarbamoyl) isourea acts as a potent GA3-synergist in stimulating shoot growth of rice seedlings. Studies with several structurally related compounds show that the alkoxycarbonylcarbamoyl-isourea or -isothiourea skeleton is required for biological activity. Any chemical deletion from this skeleton causes complete loss of activity. From present and previous data it seems that alkoxycarbonylcarbamoyl-isourea or -isothiourea is converted by intramolecular cyclization in the rice seedlings into the corresponding triazinone that serves as the active form. 相似文献
103.
Shigenori Tanaka Takanori Nakamura Takashi Morita Sadaaki Iwanaga 《Biochemical and biophysical research communications》1982,105(2):717-723
Exposure of amebocytes to bacterial endotoxins (lipopolysaccharides, LPS) results in the activation of the coagulation system, which consists of several protein components. During the separation of these components, a potent anticoagulant, named tentatively anti-LPS factor, which inhibits the endotoxin-mediated coagulation reaction, was found in both amebocytes from the hemolymphs of and . The principle purified partially from amebocyte lysate had a molecular weight less than 10,000, as judged with the ordinary gelfiltration experiment. It inhibited specifically the activation of factor B, which has recently been characterized to be a coagulation factor highly sensitive to LPS, but it did not inhibit the activities of the active factor B and the active clotting enzyme separated from the lysate. The inhibitory activity of anti-LPS factor disappeared almost completely by the treatments with pronase-P and subtilisin, suggesting its polypeptide-like substance, but it resisted to a boiling treatment. A possible site of the anticoagulant action on the coagulation system was discussed. 相似文献
104.
Mitsuro Nakano Toshihiro Hidaka Takashi Ueta Ryohei Ogura 《Prostaglandins & other lipid mediators》1983,25(4):503-510
Incubation of [1-14C]arachidonic acid (AA) with homogenates of bovine gallbladder muscle generated a large amount of radioactive material having the chromatographic mobility of 6-keto-PGF1α (stable product of PGI2) and smaller amounts of products that comigrated with PGF2α and PGE2. Formation of these products was inhibited by the cyclooxygenase inhibitor indomethacin. The major radioactive product identified by thin-layer chromatographic mobility and by gas chromatography - mass spectrometric analysis was found to be 6-keto-PGF1α. The quantitative metabolic pattern of [1-14C]PGH2 was virtually identical to that of [1-14C]AA. Incubation of arachidonic acid with slices of bovine gallbladder muscle released labile anti-aggregatory material in the medium, which was inhibited by aspirin or 15-hydroperoxy-AA.These results indicate that bovine gallbladder muscle has a considerable enzymatic capacity to produce PGI2 from arachidonic acid. 相似文献
105.
Takehiko Watanabe Yoshitaka Taguchi Yukihiko Kitamura Kenichiro Tsuyama Hirota Fujiki Hiroshi Tanooka Takashi Sugimura 《Biochemical and biophysical research communications》1982,109(2):478-485
The effects of various promoters in two-step carcinogenesis on the induction of histidine decarboxylase in the skin of mice was investigated. The potencies of various phorbol esters in inducing histidine decarboxylase activity were parallel with their tumor-promoting activities. Indole alkaloids such as dihydroteleocidin B and lyngbyatoxin A, which induced ornithine decarboxylase and promoted tumor development in the skin of mice with the same potency as 12-O-tetradecanoylphorbol-13-acetate (TPA), also induced histidine decarboxylase activity. These results suggest that histamine produced by this inducible histidine decarboxylase may play some role in tumor promotion. 相似文献
106.
Changes in Electrophoretic Patterns of Oocyte Proteins during Oocyte Maturation in Oryzias latipes 总被引:2,自引:2,他引:0
Takashi Iwamatsu Susumu Y. Takahashi Masamichi Oh-ishi Takashi Yokochi Hiroko Maeda 《Development, growth & differentiation》1992,34(2):173-179
Changes in the two-dimensional SDS-electrophoretic patterns of extracts of maturing denuded oocytes of the medaka ( Oryzias latipes ) were surveyed. In oocytes without follicular constituents several proteins became detectable in the area between the acidic and slightly basic proteins on the two-dimensional electrophoretograms, while a few of the protein spots disappeared during the process of oocyte maturation. The former proteins were detected also in oocytes that were induced to mature in vivo without breakdown of the germinal vesicle. Several proteins newly observed in extracts of post-vitellogenic oocytes during maturation after breakdown of the germinal vesicle were also identified by two-dimensional electrophoresis. Of several proteins that exhibited noticeable changes in maturing oocytes, only one spot incorporated 14 C-labeled amino acid during maturation, suggesting that post-translational modification of many proteins occurred during oocyte maturation. 相似文献
107.
Changes in activities of enzymes and levels of antioxidant substratesinvolved in the -detoxification system in seedlings of rice (Oryza sativa L. cv. Yamabiko) inresponse to variations in the oxygen environment were studied.Activities of superoxide dismutase, ascorbate peroxidase, monodehydroascorbatereductase, dehydroascorbate reductase, glutathione reductaseand catalase, expressed either on the basis of fresh weightof shoots or relative to levels of soluble protein were muchlower in seedlings germinated under water for 6 days than inthose germinated in air for the same period of time. When submergedseedlings were exposed to air, the activities of these six enzymesincreased to or exceeded the levels in aerobically grown controlsduring 24 h of adaptation to air. Ascorbate and glutathione,which act as antioxidant substrates in the -detoxification system, were present in submergedseedlings at nearly the same levels as those found in aerobicallygrown controls. On exposure of submerged seedlings to air, thelevel of ascorbate in creased slightly, but the level of glutathioneshowed a rapid increase, reaching 7 times that in aerobicallygrown controls within 12 h of adaptation to air. Levels of allsix antioxidative enzymes and of two substrates involved inthe detoxification of the superoxide radical increased withincreases in oxygen tension in the environment. Moreover, thedevelopment of this system consisted of two steps, namely, arapid increase in the level of glutathione and a subsequentslow increase in the activities of antioxidative enzymes.
1 Present address: Research Institute for Bioresources, OkayamaUniversity, Kurashiki, 710 Japan. 相似文献
108.
Dai Kitamoto Takashi Nakane Noriko Nakao Tadaatsu Nakahara Takeshi Tabuchi 《Applied microbiology and biotechnology》1992,36(6):768-772
Summary
Candida antarctica strain T-34, which was isolated as a biosurfactant producer, was found to produce organic acids and polyols extracellularly but not to produce biosurfactants, when grown on glucose or other carbohydrates as the sole carbon source. It was also observed microscopically that the strain contained oil globules within the cells. The intracellular lipids of the strain mainly consisted of triglycerides and mannosylerythritol lipids (MEL). The MEL content of the cells during the culture exceeded 10% of the dry cell weight, and the pattern of variation of the MEL content was very similar to that of triglycerides. All three stock strains of C. antarctica tested also accumulated a relatively large amount of MEL from glucose. These results suggested that these strains accumulated the MEL intracellularly as one of the storage materials together with triglycerides.Offprint requests to: D. Kitamoto 相似文献
109.
To study the distribution of rhodanese (E.C. 2.8.1.1) in plants, rhodanese activity was assayed on 13 cyanogenic and 12 non-cyanogenic
species. All the species tested had the enzyme activity. This phenomenon leads to a hypothesis that the enzyme is generally
distributed in plants. 相似文献
110.
Takashi Ariizumi Naomi Moriya Hideho Uchiyama Makoto Asashima 《Development genes and evolution》1991,200(4):230-233
Summary Human recombinant activin A, which is identical with erythroid differentiation factor (EDF), was tested for its mesoderm-inducing activity in concentrations from 0.3–50 ng/ml, using ectoderm of Xenopus late blastula (Stage 9) as the responding tissue. At a low concentration of activin A, blood-like cells, mesenchyme, and coelomic epithelium were induced; at a moderate concentration muscle and neural tissue, and at a high concentration notochord. Activin A thus induced all mesodermal tissues in a dose-dependent manner, such that a low dose induced ventral structures and a high dose induced dorsal structures. Activin may act as an intrinsic inducing molecule responsible for establishing the dorso-ventral axis in early Xenopus development.
Offprint requests to: M. Asashima 相似文献