ITOH Toshimasa

J-GLOBAL         Last updated: Oct 1, 2018 at 10:15
ITOH Toshimasa
Showa Pharmaceutical University
Faculty of Pharmaceutical Sciences
Job title
Associate Professor
Doctor (Pharmacy)(Tokyo University of Pharmacy and Life Science)

Research Areas


Academic & Professional Experience

Aug 2006
Oct 2008
Research Associate, Biochemistry, Structural Biology, University of Leicester
Apr 2005
Aug 2006
Visiting Scientist, Structural Study, MRC-LMB
Mar 2006
Mar 2006
Biochemistry & Molecular Biology,, University of Debrecen,
Institute of Biomaterials and Bioengineering,
Tokyo Medical and Dental University, Posdoc.
- Institute of Biomaterials and Bioengineering,
Tokyo Medical and Dental University,
JSPS Research Fellow


Pharmacy, Graduate School, Division of Pharmaceutical Sciences, Tokyo University of Pharmacy and Life Science
Pharmacy, Faculty of Pharmaceutical Science, Tokyo University of Pharmacy and Life Science


Daichi Egawa, Toshimasa Itoh, Keiko Yamamoto
Bioconjugate Chemistry   26 690-698   Apr 2015
© 2015 American Chemical Society. Covalent modification of proteins is important for normal cellular regulation. Here, we report on the covalent modification of peroxisome proliferator-activated receptor γ (PPARγ), an important drug target, by oxo...
Yoshinori Yamamoto, Toshimasa Itoh, Keiko Yamamoto
Journal of Nutritional Science and Vitaminology   61 222-227   Jan 2015
© 2015, Center for Academic Publications Japan. All rights reserved. Hexacosanoic acid (C26:0) (1), a very long-chain fatty acid, is related to various diseases such as adrenoleukodystrophy (ALD), adrenomyeloneuropathy (AMN) and atherosclerosis. A...
Toshimasa Itoh, Toshimasa Itoh, Louise Fairall, Frederick W. Muskett, Charles P. Milano, Peter J. Watson, Nadia Arnaudo, Nadia Arnaudo, Almutasem Saleh, Christopher J. Millard, Mohammed El-Mezgueldi, Fabrizio Martino, Fabrizio Martino, John W R Schwabe
Nucleic Acids Research   43 2033-2044   Feb 2015
© 2015 The Author(s). Recent proteomic studies have identified a novel histone deacetylase complex that is upregulated during mitosis and is associated with cyclin A. This complex is conserved from nematodes to man and contains histone deacetylase...
Hideyuki Inui, Toshimasa Itoh, Keiko Yamamoto, Shin Ichi Ikushiro, Toshiyuki Sakaki
International Journal of Molecular Sciences   15 14044-14057   Aug 2014
Polychlorinated dibenzo-p-dioxins (PCDDs) and coplanar polychlorinated biphenyls (PCBs) contribute to dioxin toxicity in humans and wildlife after bioaccumulation through the food chain from the environment. The authors examined human and rat cyto...
Yasuaki Anami, Toshimasa Itoh, Daichi Egawa, Nobuko Yoshimoto, Keiko Yamamoto
Journal of Medicinal Chemistry   57 4351-4367   May 2014
We are continuing to study the structural basis of vitamin D receptor (VDR) agonism and antagonism by using 22S-alkyl vitamin D analogues. Here we report the synthesis and biological evaluation of 22R-alkyl analogues and the X-ray crystallographic...
Keiko Yamamoto, Yasuaki Anami, Toshimasa Itoh
Current Topics in Medicinal Chemistry   14 2378-2387   Jan 2014
© 2014 Bentham Science Publishers. The first determination of the X-ray crystal structure of the ligand binding domain (LBD) of the vitamin D receptor (VDR) complexed with 1α, 25-dihydroxyvitamin D3 was reported in 2000. Since then several dozen c...
Steve Y. Rhieu, Andrew J. Annalora, Erika Laporta, Joellen Welsh, Toshimasa Itoh, Keiko Yamamoto, Toshiyuki Sakaki, Tai C. Chen, Milan R. Uskokovic, G. Satyanarayana Reddy
Journal of Cellular Biochemistry   115 1392-1402   Jan 2014
The potency of 25-hydroxyvitamin D3 (25(OH)D3) is increased by several fold through its metabolism into 1α,25- dihydroxyvitamin D3 (1α,25(OH)2D3) by cytochrome P450 27B1 (CYP27B1). Thus, the pivotal role of 1α-hydroxylation in the activation of vi...
Nobuko Yoshimoto, Nobuko Yoshimoto, Toshimasa Itoh, Toshimasa Itoh, Yuka Inaba, Yuka Inaba, Yuka Inaba, Hidemi Ishii, Hidemi Ishii, Keiko Yamamoto, Keiko Yamamoto
Journal of Medicinal Chemistry   56 7527-7535   Oct 2013
Activated thrombin-activatable fibrinolysis inhibitor (TAFIa) is a zinc-containing carboxypeptidase and significantly inhibits fibrinolysis. TAFIa inhibitors are thus expected to act as profibrinolytic agents. We recently reported the design and s...
Kaori Yasuda, Shinichi Ikushiro, Shuto Wakayama, Toshimasa Itoh, Keiko Yamamoto, Masaki Kamakura, Eiji Munetsuna, Miho Ohta, Toshiyuki Sakaki
Drug Metabolism and Disposition   40 1917-1926   Oct 2012
Sesamin and episesamin are two epimeric lignans that are found in refined sesame oil. Commercially available sesamin supplements contain both sesamin and episesamin at an approximate 1:1 ratio. Our previous study clarified the sequential metabolis...
Nobuko Yoshimoto, Nobuko Yoshimoto, Yuta Sakamaki, Yuta Sakamaki, Minoru Haeta, Akira Kato, Yuka Inaba, Toshimasa Itoh, Makoto Nakabayashi, Nobutoshi Ito, Keiko Yamamoto, Keiko Yamamoto
Journal of Medicinal Chemistry   55 4373-4381   May 2012
Previously, we reported that 22S-butyl-25,26,27-trinor-1α24- dihydroxyvitamin D 32 represents a new class of antagonist for the vitamin D receptor (VDR). The crystal structure of the ligand-binding domain (LBD) of VDR complexed with 2 showed the f...
Diego Iglesias-Gato, Shasha Zheng, John N. Flanagan, Lan Jiang, Atsushi Kittaka, Toshiyuki Sakaki, Keiko Yamamoto, Toshimasa Itoh, Nathan K. Lebrasseur, Gunnar Norstedt, Tai C. Chen
Journal of Steroid Biochemistry and Molecular Biology   127 269-275   Nov 2011
The active form of vitamin D 3, 1α,25-dihydroxyvitamin D 3(1α,25(OH) 2D 3), has anti-proliferative and anti-invasive activities in prostate cancer cells. Because of 1α,25(OH) 2D 3 therapeutic potential in treating cancers, numerous analogues have ...
Toshimasa Itoh, Ayako Tomiyasu, Ayako Tomiyasu, Keiko Yamamoto
Lipids   46 455-461   May 2011
Tetracosahexaenoic acid (C 24:6n-3, THA, 3) is an essential biosynthetic precursor in mammals of docosahexaenoic acid (C 22:6n-3, DHA, 1), the end-product of the metabolism of n-3 fatty acids. THA 3 is present in commercially valuable fishes, such...
Kiyoshi Yamazaki, Motoharu Suzuki, Motoharu Suzuki, Toshimasa Itoh, Keiko Yamamoto, Miki Kanemitsu, Chisato Matsumura, Takeshi Nakano, Toshiyuki Sakaki, Yasuo Fukami, Yasuo Fukami, Hiromasa Imaishi, Hiromasa Imaishi, Hiromasa Imaishi, Hideyuki Inui, Hideyuki Inui, Hideyuki Inui
Journal of Biochemistry   149 487-494   Apr 2011
Coplanar polychlorinated biphenyls included in dioxin-like compounds are bio-accumulated and adversely affect wildlife and human health. Although many researchers have studied the metabolism of PCBs, there have been few reports of the in vitro met...
Hitomi Takemura, Hitomi Takemura, Toshimasa Itoh, Keiko Yamamoto, Hiroyuki Sakakibara, Hiroyuki Sakakibara, Kayoko Shimoi, Kayoko Shimoi, Kayoko Shimoi
Bioorganic and Medicinal Chemistry   18(17) 6310-6315   Sep 2010
Cytochrome P450 (CYP) 1B1 catalyzes 17β-estradiol (E2) to predominantly carcinogenic 4-hydroxy-E2, whereas CYP1A1 and 1A2 convert E2 to non-carcinogenic 2-hydroxy-E2. Hence, selective inhibition of CYP1B1 is recognized to be beneficial for the pre...
Yuka Inaba, Yuka Inaba, Makoto Nakabayashi, Toshimasa Itoh, Nobuko Yoshimoto, Teikichi Ikura, Nobutoshi Ito, Masato Shimizu, Keiko Yamamoto
Journal of Steroid Biochemistry and Molecular Biology   121 146-150   Jul 2010
We recently reported that 22S-butyl-1α,24R-dihydroxyvitamin D3 3 recovers the agonistic activity for vitamin D receptor (VDR), although its 25,26,27-trinor analog 2 is a potent VDR antagonist. To investigate the structural features involved in the...
Toshimasa Itoh, Hitomi Takemura, Hitomi Takemura, Kayoko Shimoi, Keiko Yamamoto
Journal of Chemical Information and Modeling   50(6) 1173-1178   Jun 2010
CYP1A1 and CYP1A2 exhibit catalytic activity predominantly for the 2-hydroxylation of estradiol, whereas CYP1B1 exhibits catalytic activity predominantly for 4-hydroxylation of estradiol. To understand why CYP1B1 predominantly hydroxylates the 4-p...
Toshimasa Itoh, Nobuko Yoshimoto, Keiko Yamamoto, Keiko Yamamoto
Heterocycles   80(1) 689-695   Jan 2010
To study structure-activity relationships of oxidized fatty acids for the activation of peroxisome proliferator-activated receptors (PPARs), which are ligand-dependent transcription factors, we synthesized a series of oxidized fatty acids via iodo...
Yuki Yoshida, Kunihiko Mohri, Kimiaki Isobe, Toshimasa Itoh, Keiko Yamamoto, Keiko Yamamoto
Journal of Organic Chemistry   74(16) 6010-6015   Jan 2009
(Chemical Equation Presented) Erymelanthine 1 and 8-oxoerymelanthine 2 are unique erythrina alkaloids containing a pyridine ring. We synthesized (±)-8-oxoerymelanthine 2 in 2.0% overall yield using the following key reactions. The characteristic 6...
Toshimasa Itoh, Louise Fairall, Kush Amin, Yuka Inaba, Attila Szanto, Balint L. Balint, Laszlo Nagy, Keiko Yamamoto, John W R Schwabe
Nature Structural and Molecular Biology   15(9) 924-931   Sep 2008
The nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) has important roles in adipogenesis and immune response as well as roles in both lipid and carbohydrate metabolism. Although synthetic agonists for PPARγ are widely used as ...
Toshimasa Itoh, Keiko Yamamoto
Naunyn-Schmiedeberg's Archives of Pharmacology   377 541-547   Jun 2008
PPARγ regulates the expression of numerous genes. In addition to their anti-diabetic activity, PPARγ agonists have been reported to have beneficial effects for cancer, inflammation including inflammatory bowel disease, atherosclerosis and brain in...
Keiko Yamamoto, Yuichi Ninomiya, Mioko Iseki, Yutaka Nakachi, Yukiko Kanesaki-Yatsuka, Yu Yamanoue, Toshimasa Itoh, Yasuho Nishii, Nikolai Petrovsky, Yasushi Okazaki, Yasushi Okazaki
Biochemical and Biophysical Research Communications   367(3) 566-572   Mar 2008
(5E,7Z,10Z,13Z,16Z,19Z)-4-Hydroxy-5,7,10,13,16,19-docosahexaenoic acid (4-OHDHA) is a potential agonist of peroxisome proliferator-activated receptor-γ (PPARγ) and antidiabetic agent as has been previously reported. As PPARγ agonists may also have...
Toshimasa Itoh, Itsuki Murota, Kazuyoshi Yoshikai, Sachiko Yamada, Keiko Yamamoto
Bioorganic and Medicinal Chemistry   14 98-108   Jan 2006
To discover novel peroxisome proliferator-activated receptor γ (PPARγ) agonists that could be used as antidiabetic agents, we designed docosahexaenoic acid (DHA) derivatives (2 and 3), which have a hydrophilic substituent at the C(4)-position, bas...
Keiko Yamamoto, Toshimasa Itoh, Daijiro Abe, Daijiro Abe, Masato Shimizu, Tomoatsu Kanda, Takatoshi Koyama, Masazumi Nishikawa, Tadakazu Tamai, Hiroshi Ooizumi, Sachiko Yamada, Sachiko Yamada
Bioorganic and Medicinal Chemistry Letters   15(3) 517-522   Feb 2005
We found that putative metabolites of docosahexaenoic acid (DHA) are strong PPARγ activators and potential antidiabetic agents. We designed DHA derivatives based on the crystal structure of PPARγ, synthesized them and evaluated their activities in...
Mihwa Choi, Keiko Yamamoto, Toshimasa Itoh, Makoto Makishima, David J. Mangelsdorf, Dino Moras, Hector F. DeLuca, Sachiko Yamada
Chemistry and Biology   10 261-270   Mar 2003
We present a new method to investigate the details of interaction between vitamin D nuclear receptor (VDR) and various ligands, namely a two-dimensional alanine scanning mutational analysis. In this method, the transactivation of various ligands i...
Synthesis of 1-Azaspirocycles via Lewis Acid-Mediated Spirocyclization of Cyclic N-Acyl-N, O-acetal
Synlett   1506-1510   2003
Chemistry & Biology
Interactio between Vitamin D Receptor and Vitamin D Ligands : TWO Dimensional Alanine Scanning Mutational Analysis   10 261-270   2003
Organic Letters   4(15) 2469-2472   2002
Asymmetric Synthesis of (-)-Indolizidine 167B and 209D Based 07 Stereocontrolled Allylation of a Chiral Tricydic N-Acyl-N, O-acetal
Organic Letters   2 465-467   2000
Facile Total Synthesis of (±)-Adalinine
Synlett   37-40   1999