Rika Obata
Kitasato University
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Publication
Featured researches published by Rika Obata.
Bioorganic & Medicinal Chemistry Letters | 1995
Rika Obata; Toshiaki Sunazuka; Hiroshi Tomoda; Yoshihiro Harigaya; Satoshi Ōmura
Abstract Modification and structure-activity relationships of ACAT inhibitor pyripyropene were examined. PR-109 (7g) showed the most potent (IC50 = 6 nM) inhibitory activity. PR-86 (2e) also had strong inhibitory activity (IC50 = 19 nM) and its in vivo activity improved 10 times better (ED50 = 10 mg/kg) than that of pyripyropene A.
Bioorganic & Medicinal Chemistry Letters | 2000
Rika Obata; Toshiaki Sunazuka; Kazuhiko Otoguro; Hiroshi Tomoda; Yoshihiro Harigaya; Satoshi Ōmura
Natural product acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor pyripyropene A was synthetically converted to acetylcholinesterase (AChE) inhibitor via heterolitic cleavage of the 2-pyrone ring, followed by gamma-acylation/cyclization with several aroyl chlorides. The 4-pyridyl analogue selectively showed AChE inhibitory activity (IC50 7.9 microM) and no ACAT inhibitory activity IC50 = >1000 microM.
Journal of the American Chemical Society | 1994
Hiroshi Tomoda; Hiroyuki Nishida; Young Kook Kim; Rika Obata; Toshiaki Sunazuka; Satoshi Omura; Jon Bordner; Mark A. Guadliana; Peter G. Dormer; Amos B. Smith
Journal of Organic Chemistry | 1995
Tohru Nagamitsu; Toshiaki Sunazuka; Rika Obata; Hiroshi Tomoda; Haruo Tanaka; Yoshihiro Harigaya; Satoshi Omura; Amos B. Smith
The Journal of Antibiotics | 1996
Rika Obata; Toshiaki Sunazuka; Zhuorong Li; Zhiming Tian; Yoshihiro Harigaya; Noriko Tabata; Hiroshi Tomoda; Satoshi Omura
Journal of Organic Chemistry | 1996
Hiroshi Tomoda; N. Tabata; Y. Nakata; Hiroyuki Nishida; Takushi Kaneko; Rika Obata; Toshiaki Sunazuka; Satoshi Omura
The Journal of Antibiotics | 2000
Rika Obata; Toshiaki Sunazuka; Yoshihiro Harigaya; Masahiko Hayashi; Mun Chual Rho; Hiroshi Tomoda; Satoshi Omura
The Journal of Antibiotics | 1996
Rika Obata; Toshiaki Sunazuka; Yumiko Kato; Hiroshi Tomoda; Yoshihiro Harigaya; Satoshi Omura
The Journal of Antibiotics | 1997
Rika Obata; Toshiaki Sunazuka; Zhiming Tian; Hiroshi Tomoda; Yoshihiro Harigaya; Satoshi Omura
The Journal of Antibiotics | 1995
Rika Obata; Toshiaki Sunazuka; Li Zhuorong; Hiroshi Tomoda; Satoshi Omura
