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51.
Yasuo Kimura Nobutaka Takahashi Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(10):1507-1516
Biosynthesis of piericidins A and B (PA and PB) has been investigated using 14C-labeled compounds. Incorporation ratios of dl-methionine(methyl-14C), propionate-1-14C and acetate-1-14C and-2-14C were 7.4, 4,5, 1.2 and 0.9%, respectively, whereas dl-mevalonic lactone- 2-14C and formate-14C were not incorporated. Degradation studies on labeled PA show that in the biosynthesis of piericidins a long branched C23-chain was formed from five propionate and four acetate units and then a nitrogen atom was introduced at the terminal part of the chain, followed by cyclization to form the pyridine ring. The two methoxyl groups on the rings of PA and PB as well as the one in the side chain of PB were derived from S-methyl of methionine. 相似文献
52.
Hiromichi Nagasawa Akira Isogai Akinori Suzuki Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(8):1759-1763
13C-NMR spectra of isoechinulins A, B and C, metabolites from Aspergillus ruber, were fully assigned on the basis of chemical shifts and multiplicities and comparison with their analogues. Taking advantage of the symmetrical structure of the diketopiperazine ring, the stereochemistry of the trisubstituted carbon-carbon double bond in a dehydrotryptophyl moiety was determined as Z (cis) by measuring the coupling constants, , in the proton nondecoupled spectrum of isoechinulin B. 相似文献
53.
Hirotoshi Tamura Shingo Kihara Hiroshi Sugisawa 《Bioscience, biotechnology, and biochemistry》2013,77(12):3171-3176
The Retention Index (I) value and the different I values from two columns, carbowax 20M (20M) and OV101 (ΔI:I20M ? IOV101) of aliphatic compounds were calculated by several kinds of linear equations under programmed linear temperature conditions. The equations could be used to predict appropriate compounds as well as a database of I and ΔI values. 相似文献
54.
Kei Arima Teiiti Narasaki Yoshio Nakamura Gakuzo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(8):924-929
About 2000 strains of microorganisms were examined for lipoprotein lipase producibilities and some microorganisms were found to produce lipases similar to animal lipoprotein lipases.Microorganisms were cultured on solid media containing a serum-activated olive oil emulsion, and strains which formed a clear zone around the colony were collected. The collected microorganisms were cultured on liquid media containing 0.5% of olive oil by shaking and the culture filtrates were tested for lipoprotein lipase activity by a turbidity method. The superior lipoprotein lipase producers obtained belonged to genera of Serratia, Pseudomonas, Mucor, and Streptomyces. 相似文献
55.
Nobutaka Takahashi Akinori Suzuki Yasuo Kimura Satoshi Miyamoto Saburo Tamura Takashi Mitsui 《Bioscience, biotechnology, and biochemistry》2013,77(9):1115-1122
Piericidin B was isolated from mycellia of Streptomyces mobaraensis besides piericidin A. On the basis of IR, NMR and mass spectral studies together with chemical evidences, its structure was assigned as Id. Its physiological activities are also deescribd. 相似文献
56.
Noboru Murofushi Nobutaka Takahashi Takao Yokota Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(10):1239-1245
A new gibberellin, gibberellin A20 (GA20), was isolated from immature seeds of morning-glory (Pharbitis nil). Its structure was established as 4aα, 7α-dihydroxy-1β-methyl-8-methylenegibbane-1α, 10β-dicarboxylic acid-1→4a lactone (I) on the basis of its physicochemical analysis as well as chemical evidences. GA20 shows marked growth promoting activities on dwarf maize d2 and d5 but weak activities on d1, rice seedling and dwarf pea. 相似文献
57.
Saburo Tamura Makoto Takai Satoshi Miyamoto Seiroku Sakai Masayoshi Goda Yusuke Sumiki 《Bioscience, biotechnology, and biochemistry》2013,77(10):773-777
Various O,O-dialkyl O-cyanophenyl phosphates and phosphorothioates were prepared and their biological activities were examined. Among them, O,O-dimethyl O- (4-chloro-2-cyanophenyl) phosphorothioate was found to have selective and high toxicity to houseflies. O,O-Dimethyl O- (4-cyanophenyl) phosphorothioate, O,O-diethyl O- (4-cyanophenyl) phosphorothioate and O,O-diethyl O- (2-chloro-4-cyanophenyl) phosphorothioate showed high insecticidal activty to American cockroaches, though the former two were not so effective to houseflies. The dimethyl esters of these series exhibited markedly lowered mammalian toxicity. Among the O-ethyl O-cyanophenyl phenylphosphonothioates, O-ethyl O- (2-chloro-4-cyanophenyl) phenylphosphonothioate was highly effective to mites, while less effective to insects. 相似文献
58.
The milk-clotting activity of Mucor-rennin obtained from Mucor pusillus Lindt, was not changed by the addition of DFP in the reaction mixture. This finding suggested the probable absence of a serine residue at the active center of the enzyme. Sulfhydryl reagents such as Nekelgon, N-ethyl maleimide, PCMB failed to influence the milk-clotting reaction, indicating that a. reactive sulfhydryl group is not required for the enzymatic activity. The activity was inhibited when Mucor-rennin was treated with iodine at pH higher than 5.0. It was shown that 131I2 was incorporated into the enzyme. When Mucor-rennin was photooxidized in the presence of methylene blue, the milk-clotting activity was inactivated. In this case, tyrosine, tryptophan, and histidine residues in the enzyme were oxidized. Among these amino acids, the histidine residue was more rapidly oxidized than other amino acids. A parallel relation was observed between the decrease of the amount of histidine residue and the inactivation of the enzyme. From these results, it is concluded that the histidine residue present in Mucor-rennin has a relation to the active center of this enzyme. 相似文献
59.
Saburo Tamura Ching-Fun Chang Akinori Suzuki Sumio Kumai 《Bioscience, biotechnology, and biochemistry》2013,77(3):391-397
Two new isoflavonoids were isolated from red clover as germination inhibitors for the same plant and their structures were determined as a glucoside of biochanin A (7-d-β-glucosyl-5,7-dihydroxy-4′-methoxyisoflavone) (II) and its 5-malonate (I), respectively. Besides these compounds the following substances were also isolated as inhibitors: trifolirhizin (III), ononin (IV), daidzein (V) and its 7-glucoside (VI), formononetin (VII), genistein (VIII) and biochanin A (IX). 相似文献
60.