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Your search keyword '"Kentaro Tsukahara"' showing total 5 results
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5 results on '"Kentaro Tsukahara"'

1. Chromomycins A2 and A3 from Marine Actinomycetes with TRAIL Resistance-Overcoming and Wnt Signal Inhibitory Activities

Author

Kazufumi Toume, Kentaro Tsukahara, Hanako Ito, Midori A. Arai, and Masami Ishibashi

Subjects
chromomycin A2, chromomycin A3, actinomycetes, TRAIL, Wnt, Biology (General), QH301-705.5
Abstract

A biological screening study of an actinomycetes strain assembly was conducted using a cell-based cytotoxicity assay. The CKK1019 strain was isolated from a sea sand sample. Cytotoxicity-guided fractionation of the CKK1019 strain culture broth, which exhibited cytotoxicity, led to the isolation of chromomycins A2 (1) and A3 (2). 1 and 2 showed potent cytotoxicity against the human gastric adenocarcinoma (AGS) cell line (IC50 1; 1.7 and 2; 22.1 nM), as well as strong inhibitory effects against TCF/β-catenin transcription (IC50 1; 1.8 and 2; 15.9 nM). 2 showed the ability to overcome tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) resistance. To the best of our knowledge, the effects of chromomycins A2 (1) and A3 (2) on TRAIL resistance-overcoming activity, and on the Wnt signaling pathway, have not been reported previously. Thus, 1 and 2 warrant potential drug lead studies in relation to TRAIL-resistant and Wnt signal-related diseases and offer potentially useful chemical probes for investigating TRAIL resistance and the Wnt signaling pathway.

Published
2014
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2. Novel cytotoxic isobenzofuran derivatives from Streptomyces sp. IFM 11490

Author

Yixizhuoma, Masami Ishibashi, Kentaro Tsukahara, Kazufumi Toume, Naoki Ishikawa, and Mohamed S. Abdelfattah

Subjects
biology, Isobenzofuran, Chemistry, Stereochemistry, Organic Chemistry, Ethyl acetate, biology.organism_classification, Biochemistry, Streptomyces, chemistry.chemical_compound, Gastric adenocarcinoma, Cell culture, Drug Discovery, Cytotoxic T cell, Cytotoxicity, Two-dimensional nuclear magnetic resonance spectroscopy
Abstract

Three new isobenzofuran derivatives, named elmonin (1), elmenols A (2) and B (3), have been isolated from the ethyl acetate extract of the Streptomyces sp. IFM 11490. The structures of compounds 1–3 were established using extensive spectroscopic data analyses, including 1D and 2D NMR spectroscopy. The relative configuration of 2 was confirmed by single-crystal X-ray diffraction. Compounds 1 and 3 showed moderate cytotoxicity against the human gastric adenocarcinoma (AGS) cell line.

Published
2015

4. Isolation of β-indomycinone guided by cytotoxicity tests from Streptomyces sp. IFM11607 and revision of its double bond geometry

Author

Kentaro, Tsukahara, Kazufumi, Toume, Hanako, Ito, Naoki, Ishikawa, and Masami, Ishibashi

Subjects
Molecular Structure, Cell Survival, Cell Line, Tumor, Humans, Anthraquinones, Antineoplastic Agents, Streptomyces
Abstract

The antibiotic β-indomycinone was isolated from Streptomyces sp. IFM11607 by cytotoxicity-guided fractionation against human gastric adenocarcinoma AGS cells, and the geometry of its δ17,18-double bond was revised from E to Z based on the coupling constant.

Published
2015

5. Isolation of β-Indomycinone Guided by Cytotoxicity Tests from Streptomyces sp. IFM11607 and Revision of its Double Bond Geometry

Author

Masami Ishibashi, Hanako Ito, Naoki Ishikawa, Kentaro Tsukahara, and Kazufumi Toume

Subjects
Pharmacology, chemistry.chemical_classification, Double bond, biology, Stereochemistry, Geometry, Plant Science, General Medicine, biology.organism_classification, Streptomyces, Gastric adenocarcinoma, Complementary and alternative medicine, chemistry, Drug Discovery, Cytotoxicity
Abstract

The antibiotic β-indomycinone was isolated from Streptomyces sp. IFM11607 by cytotoxicity-guided fractionation against human gastric adenocarcinoma AGS cells, and the geometry of its Δ17,18-double bond was revised from E to Z based on the coupling constant.

Published
2014

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