Papers by Shin'Ichiro Kajiyama
トウダイグサ科の熱帯性植物であるJatropha curcasは, 種子に重量比40-60％の中性脂質を含み, 半乾燥地や貧栄養土壌などの荒廃地でも生育可能であるため, 近年新たなバイオディーゼ... more トウダイグサ科の熱帯性植物であるJatropha curcasは, 種子に重量比40-60％の中性脂質を含み, 半乾燥地や貧栄養土壌などの荒廃地でも生育可能であるため, 近年新たなバイオディーゼル燃料の原料植物として注目されている。しかし, 本植物の種子には発ガン促進物質であるphorbol esterを始めとする種々の毒性物質を含んでおり, その生産者の健康や環境への影響が懸念されている。そこで, 本研究では精油工程で産出される廃棄物や, 中間生成物に含まれるphorbol ester類の定量分析を行った。その結果, 搾油工程および脱ガム工程では中間生成物および廃棄物ともにphorbol ester類が多く含まれていた。一方, 脱酸工程, メチル化工程ではphorbol ester量が減少することが見いだされた。また, 最終生産物であるバイオディーゼル燃料からもphorbol ester類が微量検出された。本研究の結果は,J.curcas由来バイオディーゼルのリスク評価に寄与すると期待される。 (英文） Jatropha curcas, a tropical plant belonging to the family of Euphorbiaceae, has recently been attracted the considerable attention as a potential source for bio-diesel due to the high adaptability to semi-arid areas and the high oil content (40-60％) in seed kernel. The seed, however, contains several toxic compounds including phorbol ester, well known as a tumor promoting agent. Therefore, influence of these toxic compounds on environment and people engaged in the production should be concerned. In this study, the levels of phorbol...
Chemical Regulation of Plants, 2000
The Janapese Society for Chemical Regulation of Plants, Abstract, 2006
Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme, 1993
Phytochemistry, 1997
One novel coumarin from Angelica dahurica roots was elucidated to be 5,8-di(2,3-dihydroxy-3methyl... more One novel coumarin from Angelica dahurica roots was elucidated to be 5,8-di(2,3-dihydroxy-3methylbutoxy)-psoralen. It occurs together with six other known coumarins and ferulic acid. The antimicrobial activity of the coumarins and ferulic acid were compared.
Zeitschrift für Naturforschung C, 2002
The dual culture of Trichoderma harzianum and Catharanthus roseus callus produced an antimicrobia... more The dual culture of Trichoderma harzianum and Catharanthus roseus callus produced an antimicrobial compound with a remarkable activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. Structural elucidation revealed that this compound, which we have named trichosetin, is a novel tetramic acid (2,4-pyrrolidinedione) antibiotic and a homolog of the fungal metabolite equisetin. This compound however, was not produced in the individual culture of T. harzianum or C. roseus callus.
Tetrahedron Letters, 1990
Indolactam I. a new congener of indole alkaloid tumor promoter teleocidins, was isolated from S t... more Indolactam I. a new congener of indole alkaloid tumor promoter teleocidins, was isolated from S treptoverticillium blastmyceticum, and was shown to be biosynthesized from N-methyl-L-isoleucyl-L-tryptophanol. (-)-Indolactam V,t.2) an active fragment of indole alkaloid tumor promoter teleocidins.3)
Tetrahedron Letters, 1998
In the course of our screening program for bioactive compounds, a novel lipopeptide, nostofungici... more In the course of our screening program for bioactive compounds, a novel lipopeptide, nostofungicidine (1), was isolated from the methanolic extract of a field-grown terrestrial blue-green alga, Nostoc commune. The structure of nostofungicidine was elucidated by chemical degradation and extensive NMR measurements including DQF-COSY, HOHAHA. HMBC, and ROESY techniques. Nostofungicidine contains a novel []-amino acid, 3-amino-6-hydroxy stearic acid (Ahs) in its structure.
Tetrahedron, 1999
Three new taxoids, taxezopidines J (1), K (2), and L (3), have been isolated from seeds of the Ja... more Three new taxoids, taxezopidines J (1), K (2), and L (3), have been isolated from seeds of the Japanese yew Taxus cuspidata Sieb. et Zucc. and the structures were elucidated on the basis of spectroscopic data and chemical means. Taxezopidines K (2) and L (3) markedly inhibited Ca2+-induced depolymerization of microtubules, while taxuspine D (4), a known taxoid from the yew, induced unusual shape change of mitotic spindles like taxol.
Macromolecules, 2008
Water-absorbing materials have been sought after in the fields of cell engineering, drug controll... more Water-absorbing materials have been sought after in the fields of cell engineering, drug controlling, and planting materials.(1) A good absorption capacity for saline is very important, since various types of salts are contained in cell culture medium, body fluids, ...
Journal of Photochemistry and Photobiology A: Chemistry, 2005
Eleven Ga-phorphyrin complexes bearing various lengths of carbon-chain were synthesized and the U... more Eleven Ga-phorphyrin complexes bearing various lengths of carbon-chain were synthesized and the UV–vis spectra shift patterns in various concentrations of albumin solutions were evaluated. The distributions of these derivatives into the organs were also determined by surface fluorescence using nitrogen-pulsed laser spectrophotometry. The shift patterns between 0 and 0.9% albumin concentrations (albumin test) were correlated to their tumor localizing property. The albumin test was proved to be useful for evaluation of tumor localizing properties of porphyrin derivatives. The tumor localizing ability was increased along with increasing their lipophilicity and the derivative bearing decyl groups as side chains was a maximum. The porphyrin–albumin complex might have key mission for the passive accumulation focusing on the tumor.
Journal of Natural Products, 2010
The P450 cytochrome monooxygenase gene, ltxB, was cloned and overexpressed in Escherichia coli as... more The P450 cytochrome monooxygenase gene, ltxB, was cloned and overexpressed in Escherichia coli as a 6xHis-tagged protein. The resulting recombinant LtxB was purified by Ni-NTA affinity chromatography and characterized biochemically. Purified LtxB demonstrated typical cytochrome P450 spectroscopic properties including substrate-induced transition from a low-spin (λ max) 414 nm) to high-spin state (λ max) 386 nm) upon incubation with N-methyl-L-valyl-L-tryptophanol. The catalytic activity of LtxB was verified by demonstrating the oxidation/cyclization of N-methyl-L-valyl-L-tryptophanol to (-)-indolactam V. LtxB shows a relaxed specificity for analogue substrates in which the valyl group is substituted for other aliphatic groups. The relaxed substrate specificity of LtxB, along with the relaxed specificity of the prenyltransferase, LtxC, allowed for the enzymatic production of a series of (-)-indolactam V and lyngbyatoxin analogues.
Journal of Natural Products, 1994
Two new teleocidin-related metabolites, (-)-7-geranylindolactam-V [2] and blastmycetin F [3], wer... more Two new teleocidin-related metabolites, (-)-7-geranylindolactam-V [2] and blastmycetin F [3], were isolated from fermentation broths of the actinomycete Streptoverticillium blastmyceticum NA34-17, and their structures were determined by spectroscopic methods. Compound 2 bound strongly to phorbol ester receptors in a mouse epidermal particulate fraction, suggesting that it is a potent in vivo tumor promoter comparable to teleocidins A-1 [4] and B-4 [5].
Journal of Molecular Catalysis B: Enzymatic, 2004
Screening of a phage display random 9-mer peptide library, in which cysteine residues were at the... more Screening of a phage display random 9-mer peptide library, in which cysteine residues were at the both terminals of the 7-mer random region, was performed to obtain an oligopeptide that recognizes a chitin-oligomer. Affinity of the obtained peptide (Cys-Ser-Arg-Thr-Thr-Arg-Thr-Arg-Cys) to chitotriose was modulated by its oxidation–reduction state. Only the oxidized form exhibited specific binding to the target molecule, chitotriose. This is the first report of reversible affinity modulation of a synthetic oligopeptide which can recognize a neutral saccharide.
Journal of Chromatography A, 2001
A high-resolution analysis of polyprenol mixtures was achieved by supercritical fluid chromatogra... more A high-resolution analysis of polyprenol mixtures was achieved by supercritical fluid chromatography (SFC). The separation of polyprenols was examined on an octadecylsilane-packed column with liquid carbon dioxide as the mobile phase and ethanol as modifier. Using this chromatography system, the resolution of separation (R) between octadecaprenol s (prenol 18) and nonadecaprenol (prenol 19) was two times higher than that using conventional reversed-phase highperformance liquid chromatography. Our SFC technique allows the advantage of baseline separation of polyprenol samples containing hydrophobic components such as terpenes or fatty acids that are unfavorable for good separation. This method is very useful for the analysis of structurally close polyprenol analogues of rubber plant metabolites.
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Papers by Shin'Ichiro Kajiyama