研究者詳細 - 清田　洋正

論文 - 清田　洋正

分割表示 235 件中 121 - 140 件目／全件表示 >>

Structural characterization of neutral and anionic glucans from Mesorhizobium loti

Yasuyuki Kawaharada, Hiromasa Kiyota, Shima Eda, Kiwamu Minamisawa, Hisayuki Mitsui

CARBOHYDRATE RESEARCH 343 ( 14 ) 2422 - 2427 2008年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

The periplasmic glucans of Mesorhizobium loti were isolated and separated into fractions according to their acidity. NMR spectroscopy confirmed their backbone structure to be a cyclic beta-(1-->2)-D-glucan as in the case of other rhizobia, and revealed no non-glycosidic substituents in the neutral fraction, and glycerophosphoryl and succinyl residues as major and minor substituents, respectively, in the anionic fractions. MALDI-TOF mass spectrometry showed that the anionic glucans contain one, two, or three such substituents per molecule according to their acidity, and, in contrast, that all the anionic subfractions have a similar size distribution to that of the neutral glucans, where molecules composed of 20-24 glucosyl residues are predominant. These results clarify the periplasmic glucan composition in terms of charge-to-mass ratios in M. loti cells. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carres.2008.07.007

Web of Science

researchmap

A new pseudo-alkaloid taxane and a new rearranged taxane from the needles of Taxus canadensis

Manti Zhang, Changhong Huo, Mei Dong, Ligeng Li, Franqoise Sauriol, Qingwen Shi, Yucheng Gu, Hiromasa Kiyota, Bin Cong

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 63 ( 8 ) 1005 - 1011 2008年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WALTER DE GRUYTER GMBH

A new taxane with an amino side chain on C-5 and a new 11(15 -> 1)abeotaxane having a tetrahydrofuran ring along carbon atoms C-2, C-3, C-4, C-20 identified for the first time from the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as 2 alpha,7 beta,9 alpha, 10 beta, 13-pentaacetoxy-11 beta-hydroxy-5a-(2'-hydroxy,3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20), 12-diene (1) and 13 alpha,20 beta-diacetoxy- 5 alpha,7 beta,9 alpha,10 beta-tetrahydroxy-2 alpha,20-epoxy-11(15 -> 1)abeotaxa-11, 15-diene (2) on the basis of 1D, 2D NMR spectroscopy and high-resolution FABMS analysis. Taxane 1 contains a rare C-12, C-13 double bond and a basic side chain, while taxane 2 bears a rare isopropenyl group at C-1.

Web of Science

researchmap

A new taxane composed of two N-formyl rotamers from Taxus canadensis

Man-Li Zhang, Mei Dong, Xiao-Ning Li, Li-Geng Li, Fancoise Sauriol, Chang-Hong Huo, Qing-Wen Shi, Yu-Cheng Gu, Hiromasa Kiyota, Bin Cong

TETRAHEDRON LETTERS 49 ( 21 ) 3405 - 3408 2008年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

A taxane with an amino-side chain on C-5 was identified for the first time from rooted cuttings of the Canadian yew, Taxus camadensis. The structure was characterized as 7 beta,9 alpha,10 beta,13 alpha-tetraacetoxy-5 alpha-[3'-(N-formyl-N-methylamino)-3'-phenylpropanoyl]oxytaxa-4(20),12-diene (1) on the basis of 1D-, 2D-NMR data, and HR-FABMS analyses. The spectra revealed that in CDCl(3) solution 1 was composed of two rotamers (1a and 1b) in a ratio of approximately 2:1. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2008.03.115

Web of Science

researchmap

Echinopines A and B: Sesquiterpenoids possessing an unprecedented skeleton from Echinops spinosus

Mei Dong, Bin Cong, Shu-Hong Yu, Francoise Sauriol, Chang-Hong Huo, Qing-Wen Shi, Yu-Cheng Gu, Lolita O. Zamir, Hiromasa Kiyota

ORGANIC LETTERS 10 ( 5 ) 701 - 704 2008年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

Echinopines A (1) and B (2), novel sesquiterpenoids with an unprecedented rearranged skeleton named echinopane, were isolated from the roots of Echinops spinosus. The structures were elucidated by extensive spectroscopic analysis. The relative configuration of 1 was assigned by a combination of NOESY correlations and a simulation analysis. A plausible biosynthetic pathway for echinopane was discussed.

DOI： 10.1021/ol702629z

Web of Science

researchmap

A Novel Taxane with a Rare 9α,13α-Oxygen Bridge from Taxus cuspidata Needles

Man-Li Zhang, Bin Cong, Mei Dong, Yu-Fang Wang, Chang-Hong Huo, Yu-Cheng Gu, Qing-Wen Shi, Hiromasa Kiyota

Tetrahedron Letters 49 ( 7 ) 1180 - 1183 2008年2月

Total Synthesis of Natural Products of Microbial Origins

Hiromasa Kiyota, Shigefumi Kuwahara

Tohoku Journal of Agricultural Research 58 ( 3-4 ) 167 - 173 2008年

Two new taxanes from Taxus canadensis

Changhong Huo, Yongming Zhao, Xiaotang Si, Ligeng Li, Manli Zhang, Qingwen Shi, Hiromasa Kiyota

BIOCHEMICAL SYSTEMATICS AND ECOLOGY 35 ( 12 ) 909 - 913 2007年12月

A new taxol analogue from the leaves of Taxus cuspidata

Changhong Huo, Xiping Zhang, Cunfang Li, Wang Wang, Qingwen Shi, Hiromasa Kiyota

BIOCHEMICAL SYSTEMATICS AND ECOLOGY 35 ( 10 ) 704 - 708 2007年10月

12 エナンチオ・ディファレンシャル法によるジャスモン酸配糖体型就眠物質受容体タンパク質の生物有機化学(口頭発表の部)

中村葉子, 宮武良至, 猪俣翔, 清田洋正, 上田実

天然有機化合物討論会講演要旨集 ( 49 ) 67 - 72 2007年8月

記述言語：日本語出版者・発行元：天然有機化合物討論会

Albizzia plants close their leaves in the evening, as if to sleep, and open them in the morning according to the circadian rhythum. Potassium β-D-glucopyranosyl-12-hydroxyjasmonate was isolated as leaf-closing factor (LCF) of Albizzia saman. We developed molecular probes consisting of modified LCF in order to identify its mode of action. However, it is often discussed whether molecular probes containing a larger and less polar functional unit such as fluorescence dye can bind to genuine binding protein of a natural product in living organisms. So, we need appropriate negative control. And an enantiomer of a biologically active natural product can be used as an ideal control because all physical propaties except for optical rotation and affinity to binding proteins are identical between a pair of enantiomers. Thus, enantio-differential approach that compares the results using a pair of probes that was prepared from a pair of enantiomers would be an ideal method in the bioorganic study using molecular probes. We synthesized probe 11 and biologically inactive enantiomer-type probe 12. And carried out fluorescence labeling study using 11 and 12. The results was clearly shown that the motor cells contain some specific binding protein that can differentiate the stereochemistry of the ligands. Similarly, we synthesized enantio pair-type photoaffinity-labeling probes 20 and 21, and used them for photoaffinity labeling of receptor for LCF. By using protoplast of motor cell, we found 35kDa membrane protein strictly recognizes the stereochemistry of LCF, and it is highly likely that the protein is the specific receptor for LCF.

DOI： 10.24496/tennenyuki.49.0_67

CiNii Article

CiNii Books

researchmap

Synthesis of (-)-tabtoxinine-beta-lactam, the phytotoxin of tobacco wildfire disease

Hiromasa Kiyota, Takafumi Takai, Yasuharu Shimasaki, Masatoshi Saitoh, Osamu Nakayama, Tomoko Takada, Shigefumi Kuwahara

SYNTHESIS-STUTTGART 2007 ( 16 ) 2471 - 2480 2007年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：GEORG THIEME VERLAG KG

Synthesis of (-)-tabtoxinine-p-lactam and its (3R)-isomer, the cause of tobacco wildfire disease, was achieved from Lserine using a zinc-mediated coupling reaction, Sharpless asymmetric dihydroxylation and lactainization of beta-mesyloxy benzylhydroxamate amide as the key steps.

DOI： 10.1055/s-2007-983785

Web of Science

researchmap

Three New Taxanes with 10-Alkoxy Group from the Heartwood of Taxus cuspidata

Mei Dong, Man-Li Zhang, Yu-Fang Wang, Xi-Ping Zhang, Cun-Fang Li, Qing-Wen Shi, Bin Cong, Hiromasa Kiyota*

Bioscience, Biotechnology, and Biochemistry 71 ( 8 ) 2087 - 2090 2007年8月

New 14-hydroxy-taxane and 2 alpha,20-epoxy-11(15 -> 1)abeotaxane from the needles of Taxus canadensis

Qing-Wen Shi, Mei Dong, Chang-Hong Huo, Xiao-Hui Su, Cun-Fang Li, Xi-Ping Zhang, Yu-Fang Wang, Hiromasa Kiyota

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 71 ( 7 ) 1777 - 1780 2007年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

Two new taxanes were isolated from the needles of Taxus canadensis. Their structures were established as 10 beta,13 alpha-diacetoxytaxa-4(20),11-diene-5 alpha,9 alpha,14 beta-triol (1) and 4 alpha,13 alpha-diacetoxy-2 alpha,20-epoxy-11(15 -> 1)abeotaxa-11,15-diene-5 alpha,7 beta,9 alpha,10 beta-tetraol (2) on the basis of a spectroscopic analysis.

DOI： 10.1271/bbb.70063

Web of Science

researchmap

Structural Determination of a New 2(3->20)Abeotaxane with an Unusual13b-Substitution and a New 6/8/6-Ring Taxane from Taxus cuspidata

Chang-Hong Huo, Xiao-Hui Su, Xing Li, Xi-Ping Zhang, Cun-Fang Li, Yu-Fang Wang, Qing-Wen Shi, Hiromasa Kiyota

Magnetic Resonance in Chemistry 45 ( 6 ) 527 - 530 2007年6月

Chemical Constituents in the Genus Wedelia and their Bioactivity 査読

Xing Li, Mei Dong, Yong Liu, Qing-Wen Shi, Hiromasa Kiyota*

Chemistry and Biodiversity 4 ( 4 ) 823 - 836 2007年4月

Canataxpropellane, a novel taxane with a unique polycyclic carbon skeleton (tricyclotaxane) from the needles of Taxus canadensis

Chang-Hong Huo, Xiao-Hui Su, Yu-Fang Wang, Xi-Ping Zhang, Qing-Wen Shi, Hiromasa Kiyota

TETRAHEDRON LETTERS 48 ( 15 ) 2721 - 2724 2007年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

A novel taxane with an unprecedented 5/5/4/6/6/6-membered hexacyclic skeleton containing [3.3.2]propellane was isolated from the needles of the Canadian yew, Taxus canadensis. The structure was established as 2 alpha,10 beta-diaectoxy-5 alpha,9 alpha,20 alpha-trihydroxy-3 alpha- 11 alpha;4 alpha, 12 alpha;14 alpha,20-tricyclotaxan-13-one (1), which exists as two conformational isomers on the basis of spectroscopic analysis. This compound would be biogenetically derived from a normal 6/8/6-taxane by the intramolecular aldol reaction and [2+2] cycloaddition. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2007.02.063

Web of Science

researchmap

Synthesis and odor description of optically active cyclopropanated analogues of geraniol, nerol, nor-leaf alcohol, and matsutake alcohol

Hiroki Asao, Hiroyuki Sakauchi, Shigefumi Kuwahara, Hiromasa Kiyota

TETRAHEDRON-ASYMMETRY 18 ( 4 ) 537 - 541 2007年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Both enantiomers of cyclopropanated analogues of geraniol, nerol, nor-leaf alcohol, and matsutake alcohol were synthesized and their odor properties evaluated. Odor characters in enantiomeric pairs were similar in the geraniol series. The (+)-(2R,3S)-nerol derivative showed various odor aspects. From the results of nor-leaf alcohol derivatives, an interaction between the (2-re,3-re)-face of nor-leaf alcohol and the human olfactory receptor was suggested. The odor of (3R)-matsutake alcohol derivative was superior to the enantiomer. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetasy.2007.02.007

Web of Science

researchmap

A new metabolite with a new substitution pattern from the seeds of the Chinese yew, Taxus mairei

Chang-Hong Huo, Yu-Fang Wang, Xi-Ping Zhang, Cun-Fang Li, Qing-Wen Shi, Hiromasa Kiyota

CHEMISTRY & BIODIVERSITY 4 ( 1 ) 84 - 88 2007年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-V C H VERLAG GMBH

A new taxoid metabolite with a new substitution pattern was isolated from the methanol extract of the seeds of Taxus mairei, and its structure was established as 5 alpha,15-dihydroxy-7 beta 9 alpha-diacetoxy-11(15 -> 1)abeo-taxa-4(20),11-dien-13-one (1) on the basis of spectral analysis including H-1- and C-13-NMR, HMQC, HMBC, NOESY, and confirmed by HR-FAB mass spectrometry.

DOI： 10.1002/cbdv.200790009

Web of Science

researchmap

Structures and biological properties of the chemical constituents from the genus Wedelia

Xing Li, Mei Dong, Yong Liu, Qing-Wen Shi, Hiromasa Kiyota

Chemistry and Biodiversity 4 ( 5 ) 823 - 836 2007年

Chemical Constituents from Genus Laggera

Xing-Cui Li, Chang-Hong Huo, Qing-Wen Shi, Hiromasa Kiyota*

Chemistry and Biodiversity 4 ( 2 ) 105 - 111 2007年

Stereochemistry of enacyloxins - Part 4 - Complete structural and configurational assignment of the enacyloxin family, a series of antibiotics from Frateuria sp W-315 査読

Hiroyuki Furukawa, Hiromasa Kiyota, Teiko Yamada, Manabu Yaosaka, Ryo Takeuchi, Toshihiko Watanabe, Shigefumi Kuwahara

CHEMISTRY & BIODIVERSITY 4 ( 7 ) 1601 - 1604 2007年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-V C H VERLAG GMBH

The absolute configurations of the enacyloxins, a series of polyhydroxylated polyene antibiotics from Frateuria species, were determined. The so far elusive (13'R,14'R,15'S)-configuration was assigned to enacycloxin IVa (1) by means of 'J-resolved HMBC-1' and NOESY NMR methods.

Web of Science

researchmap

　前のページ - 次のページ　

<清田 洋正>

論文 - 清田 洋正

<清田　洋正>

論文 - 清田　洋正