The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
Masanobu Kohsaka - One of the best experts on this subject based on the ideXlab platform.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Nobuharu Shigematsu, Shigehiro Takase, Toshio Goto, Masanobu KohsakaAbstract:R1128 B (l, 3, 6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128B for partially purified rat uterine Cytosol Receptor was 1.2×10-7 M. However, the IC50 value of Rl 128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. Rl 128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. Rl 128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces i taxonomy fermentation isolation and biological properties
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Masami Ezaki, Toshio Goto, Masanobu KohsakaAbstract:: New non-steroidal estrogen-Receptor antagonists, R1128 A, B, C and D, were isolated from the cultured broth of Streptomyces sp. No. 1128 by solvent extraction, silica gel chromatography, reverse phase chromatography and preparative HPLC. These compounds inhibited estrogen binding to its Receptor. The IC50 values of R1128 A, B, C and D for partially purified rat uterine Cytosol Receptor were 1.1 x 10(-7) M, 1.2 x 10(-7) M, 2.6 x 10(-7) M and 2.7 x 10(-7) M, respectively.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces iii pharmacological properties and antitumor activities
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Makoto Nishimura, Toshio Goto, Masanobu KohsakaAbstract:: R1128 B (1,3,6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128 B for partially purified rat uterine Cytosol Receptor was 1.2 x 10(-7) M. However, the IC50 value of R1128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. R1128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. R1128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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WB2838 [3-CHLORO-4-(2-AMINO-3-CHLOROPHENYL)-PYRROLE]: NON-STEROIDAL ANDROGEN-Receptor ANTAGONIST PRODUCED BY A Pseudomonas
The Journal of antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Shigehiro Takase, Toshio Goto, Yukiko Abe, Hidenori Nakajima, Takashi Fujita, Masanobu KohsakaAbstract:In the course of our search for non-steroidal androgen-Receptor antagonists of microbial origin, Pseudomonas sp. No. 2838 was found to produce an inhibitor of androgen binding to its Receptor. This compound, named WB2838, was isolated and identified as 3-chloro-4-(2-amino-3-chlorophenyl)-pyrrole. The IC50 value of WB2838 for partially purified rat prostate Cytosol Receptor was 8.0 × 10-7 M. However, the IC50 value of WB2838 against estrogen-Receptor binding was about 90-fold greater than that against androgen-Receptor binding. WB2838 inhibited the growth of androgen-responsive mouse mammary carcinoma SC-3 cells in the presence of 10-8M testosterone at IC50 value of 4.1 × 10-7M. This inhibition was reversed by adding 10-5M testosterone to the culture medium. WB2838 also showed the inhibitory activity against the growth of the ventral prostate induced by testosterone propionate in castrated immature rats. Therefore, it was concluded that WB2838 was a non-steroidal androgen-Receptor antagonist.
Yasuhiro Hori - One of the best experts on this subject based on the ideXlab platform.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Nobuharu Shigematsu, Shigehiro Takase, Toshio Goto, Masanobu KohsakaAbstract:R1128 B (l, 3, 6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128B for partially purified rat uterine Cytosol Receptor was 1.2×10-7 M. However, the IC50 value of Rl 128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. Rl 128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. Rl 128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces i taxonomy fermentation isolation and biological properties
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Masami Ezaki, Toshio Goto, Masanobu KohsakaAbstract:: New non-steroidal estrogen-Receptor antagonists, R1128 A, B, C and D, were isolated from the cultured broth of Streptomyces sp. No. 1128 by solvent extraction, silica gel chromatography, reverse phase chromatography and preparative HPLC. These compounds inhibited estrogen binding to its Receptor. The IC50 values of R1128 A, B, C and D for partially purified rat uterine Cytosol Receptor were 1.1 x 10(-7) M, 1.2 x 10(-7) M, 2.6 x 10(-7) M and 2.7 x 10(-7) M, respectively.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces iii pharmacological properties and antitumor activities
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Makoto Nishimura, Toshio Goto, Masanobu KohsakaAbstract:: R1128 B (1,3,6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128 B for partially purified rat uterine Cytosol Receptor was 1.2 x 10(-7) M. However, the IC50 value of R1128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. R1128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. R1128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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WB2838 [3-CHLORO-4-(2-AMINO-3-CHLOROPHENYL)-PYRROLE]: NON-STEROIDAL ANDROGEN-Receptor ANTAGONIST PRODUCED BY A Pseudomonas
The Journal of antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Shigehiro Takase, Toshio Goto, Yukiko Abe, Hidenori Nakajima, Takashi Fujita, Masanobu KohsakaAbstract:In the course of our search for non-steroidal androgen-Receptor antagonists of microbial origin, Pseudomonas sp. No. 2838 was found to produce an inhibitor of androgen binding to its Receptor. This compound, named WB2838, was isolated and identified as 3-chloro-4-(2-amino-3-chlorophenyl)-pyrrole. The IC50 value of WB2838 for partially purified rat prostate Cytosol Receptor was 8.0 × 10-7 M. However, the IC50 value of WB2838 against estrogen-Receptor binding was about 90-fold greater than that against androgen-Receptor binding. WB2838 inhibited the growth of androgen-responsive mouse mammary carcinoma SC-3 cells in the presence of 10-8M testosterone at IC50 value of 4.1 × 10-7M. This inhibition was reversed by adding 10-5M testosterone to the culture medium. WB2838 also showed the inhibitory activity against the growth of the ventral prostate induced by testosterone propionate in castrated immature rats. Therefore, it was concluded that WB2838 was a non-steroidal androgen-Receptor antagonist.
Kenneth S. Korach - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the DNA-binding domain of the mouse uterine estrogen Receptor using site-specific polyclonal antibodies.
The Journal of biological chemistry, 1993Co-Authors: Masayuki Ikeda, F Ogata, Sylvia W. Curtis, Dennis B. Lubahn, F S French, E M Wilson, Kenneth S. KorachAbstract:The DNA-binding domain of the mouse uterine estrogen Receptor (ER) was characterized using site-specific polyclonal antibodies. The peptides used as antigens have sequences corresponding to amino acids 185-199 and 227-245, the two zinc finger regions of the DNA-binding domain of the human ER, and produced anti-sera designated A-1542 and A-1554, respectively. Mouse uterine nuclear ER and salt-activated 4 S Cytosol Receptor, as well as 8 S untransformed Cytosol Receptor, were observed to react with the antisera by Western blot and sucrose density gradient centrifugation analyses indicating that the DNA-binding domain of the 8 S Cytosol Receptor is not completely masked by heat shock protein 90 or other proteins. Only A-1554 detected a nuclear-specific doublet form of the ER on Western blot analysis. In a gel shift assay, neither antisera altered the pattern of the nuclear ER interaction with the vitellogenin A2 estrogen response element (VRE). In contrast, antiserum A-1554 partially shifted the 8 S Cytosol Receptor-VRE complex. This concurs with mutational analysis and x-ray crystallography studies with the human ER that have shown that the second finger is not in contact with the DNA. The results of the gel shift assay were confirmed by sucrose density gradient analysis using the same buffer conditions. The nuclear Receptor-VRE complex did not react with either antisera, suggesting that when the dimeric nuclear Receptor form binds the VRE, the specific Receptor epitopes involved with the DNA binding may be blocked and unable to bind the antisera. The Cytosol Receptor-VRE complex reacted only partially with the second finger antisera A-1554, suggesting that on Receptor monomers the second finger epitope is not completely blocked by DNA binding or dimer formation.
Masakuni Okuhara - One of the best experts on this subject based on the ideXlab platform.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Nobuharu Shigematsu, Shigehiro Takase, Toshio Goto, Masanobu KohsakaAbstract:R1128 B (l, 3, 6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128B for partially purified rat uterine Cytosol Receptor was 1.2×10-7 M. However, the IC50 value of Rl 128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. Rl 128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. Rl 128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces i taxonomy fermentation isolation and biological properties
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Masami Ezaki, Toshio Goto, Masanobu KohsakaAbstract:: New non-steroidal estrogen-Receptor antagonists, R1128 A, B, C and D, were isolated from the cultured broth of Streptomyces sp. No. 1128 by solvent extraction, silica gel chromatography, reverse phase chromatography and preparative HPLC. These compounds inhibited estrogen binding to its Receptor. The IC50 values of R1128 A, B, C and D for partially purified rat uterine Cytosol Receptor were 1.1 x 10(-7) M, 1.2 x 10(-7) M, 2.6 x 10(-7) M and 2.7 x 10(-7) M, respectively.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces iii pharmacological properties and antitumor activities
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Makoto Nishimura, Toshio Goto, Masanobu KohsakaAbstract:: R1128 B (1,3,6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128 B for partially purified rat uterine Cytosol Receptor was 1.2 x 10(-7) M. However, the IC50 value of R1128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. R1128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. R1128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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WB2838 [3-CHLORO-4-(2-AMINO-3-CHLOROPHENYL)-PYRROLE]: NON-STEROIDAL ANDROGEN-Receptor ANTAGONIST PRODUCED BY A Pseudomonas
The Journal of antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Shigehiro Takase, Toshio Goto, Yukiko Abe, Hidenori Nakajima, Takashi Fujita, Masanobu KohsakaAbstract:In the course of our search for non-steroidal androgen-Receptor antagonists of microbial origin, Pseudomonas sp. No. 2838 was found to produce an inhibitor of androgen binding to its Receptor. This compound, named WB2838, was isolated and identified as 3-chloro-4-(2-amino-3-chlorophenyl)-pyrrole. The IC50 value of WB2838 for partially purified rat prostate Cytosol Receptor was 8.0 × 10-7 M. However, the IC50 value of WB2838 against estrogen-Receptor binding was about 90-fold greater than that against androgen-Receptor binding. WB2838 inhibited the growth of androgen-responsive mouse mammary carcinoma SC-3 cells in the presence of 10-8M testosterone at IC50 value of 4.1 × 10-7M. This inhibition was reversed by adding 10-5M testosterone to the culture medium. WB2838 also showed the inhibitory activity against the growth of the ventral prostate induced by testosterone propionate in castrated immature rats. Therefore, it was concluded that WB2838 was a non-steroidal androgen-Receptor antagonist.
Toshio Goto - One of the best experts on this subject based on the ideXlab platform.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Nobuharu Shigematsu, Shigehiro Takase, Toshio Goto, Masanobu KohsakaAbstract:R1128 B (l, 3, 6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128B for partially purified rat uterine Cytosol Receptor was 1.2×10-7 M. However, the IC50 value of Rl 128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. Rl 128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. Rl 128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces i taxonomy fermentation isolation and biological properties
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Masami Ezaki, Toshio Goto, Masanobu KohsakaAbstract:: New non-steroidal estrogen-Receptor antagonists, R1128 A, B, C and D, were isolated from the cultured broth of Streptomyces sp. No. 1128 by solvent extraction, silica gel chromatography, reverse phase chromatography and preparative HPLC. These compounds inhibited estrogen binding to its Receptor. The IC50 values of R1128 A, B, C and D for partially purified rat uterine Cytosol Receptor were 1.1 x 10(-7) M, 1.2 x 10(-7) M, 2.6 x 10(-7) M and 2.7 x 10(-7) M, respectively.
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r1128 substances novel non steroidal estrogen Receptor antagonists produced by a streptomyces iii pharmacological properties and antitumor activities
The Journal of Antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Makoto Nishimura, Toshio Goto, Masanobu KohsakaAbstract:: R1128 B (1,3,6-trihydroxy-8-n-butylanthraquinone), a new antibiotic produced by Streptomyces sp. No. 1128, inhibited estrogen binding to its Receptor. The IC50 value of R1128 B for partially purified rat uterine Cytosol Receptor was 1.2 x 10(-7) M. However, the IC50 value of R1128 B against androgen-Receptor binding was about 50-fold greater than that against estrogen-Receptor binding. R1128 B was a competitive inhibitor against estrogen-Receptor binding. R1128 B inhibited the growth of estrogen-responsive human mammary adenocarcinoma MCF-7 cells in soft agar. This inhibition, however, was reversed when estradiol was added to the culture medium. R1128 B showed antitumor activities against MCF-7 both xenografted to nude mice and implanted in subrenal capsule of mice (SRC assay). The potency of R1128 B was about 8-fold lower than that of tamoxifen both in vitro and in vivo.
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WB2838 [3-CHLORO-4-(2-AMINO-3-CHLOROPHENYL)-PYRROLE]: NON-STEROIDAL ANDROGEN-Receptor ANTAGONIST PRODUCED BY A Pseudomonas
The Journal of antibiotics, 1993Co-Authors: Yasuhiro Hori, Masakuni Okuhara, Shigehiro Takase, Toshio Goto, Yukiko Abe, Hidenori Nakajima, Takashi Fujita, Masanobu KohsakaAbstract:In the course of our search for non-steroidal androgen-Receptor antagonists of microbial origin, Pseudomonas sp. No. 2838 was found to produce an inhibitor of androgen binding to its Receptor. This compound, named WB2838, was isolated and identified as 3-chloro-4-(2-amino-3-chlorophenyl)-pyrrole. The IC50 value of WB2838 for partially purified rat prostate Cytosol Receptor was 8.0 × 10-7 M. However, the IC50 value of WB2838 against estrogen-Receptor binding was about 90-fold greater than that against androgen-Receptor binding. WB2838 inhibited the growth of androgen-responsive mouse mammary carcinoma SC-3 cells in the presence of 10-8M testosterone at IC50 value of 4.1 × 10-7M. This inhibition was reversed by adding 10-5M testosterone to the culture medium. WB2838 also showed the inhibitory activity against the growth of the ventral prostate induced by testosterone propionate in castrated immature rats. Therefore, it was concluded that WB2838 was a non-steroidal androgen-Receptor antagonist.
