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Featured researches published by Satoru Tamura.


Journal of Medicinal Food | 2010

Anti-Inflammatory Properties of Red Ginger (Zingiber officinale var. Rubra) Extract and Suppression of Nitric Oxide Production by Its Constituents

Hiroshi Shimoda; Shao-Jie Shan; Junji Tanaka; Azusa Seki; Joung-Wook Seo; Naoki Kasajima; Satoru Tamura; Yan Ke; Nobutoshi Murakami

Red ginger (Zingiber officinale var. Rubra) has been prescribed as an analgesic for arthritis pain in Indonesian traditional medicine. The surface color of the rhizome is purple because of the anthocyanidins in its peel. We prepared 40% ethanolic extract from dried red ginger (red ginger extract [RGE]) and evaluated its anti-inflammatory activity using acute and chronic inflammation models. In an acetic acid-induced mouse writhing model, RGE (10-100 mg/kg) suppressed both the frequency of writhing and the increase in permeability of abdominal capillaries. On the other hand, continuous treatment with RGE (10 mg/kg) significantly (P < .05) suppressed footpad edema in a rat adjuvant arthritis model. To clarify the anti-inflammatory mechanism of RGE, we examined the effect on prostaglandin (PG) and nitric oxide (NO) production from mouse leukemic monocytes (RAW264 cells) stimulated by lipopolysaccharide. RGE (3 and 10 microg/mL) significantly (P < .05) suppressed PGE(2) production, while it also suppressed NO production at 100 microg/mL. After bioassay-guided separation of RGE, we found that [6]-shogaol and gingerdiols suppressed NO production. Red dye fractions presumed to be proanthocyanidins also suppressed NO production at 100 microg/mL. Consequently, we found a potent suppressive effect of RGE on acute and chronic inflammation, and inhibition of macrophage activation seems to be involved in this anti-inflammatory effect. [6]-Shogaol, gingerdiols, and proanthocyanidins were identified as constituents that inhibited NO production.


Bioorganic & Medicinal Chemistry Letters | 2001

New anti-malarial flavonol glycoside from Hydrangeae Dulcis Folium

Nobutoshi Murakami; Huq Mohammad Mostaqul; Satoru Tamura; Sawako Itagaki; Toshihiro Horii; Motomasa Kobayashi

Bioassay-guided fractionation of the MeOH extract of Hydrangeae Dulcis Folium resulted in isolation of a new flavonol glycoside and two known congeners as anti-malarial principles. These flavonol glycosides showed characteristic proliferation inhibition of Plasmodium falciparum at significantly low concentration without showing any cytotoxicity. In addition, several naturally occurring flavonol glycosides were also shown to exert similar anti-malarial behavior.


Skeletal Radiology | 2013

Three-dimensional topographical variation of femoral cartilage T2 in healthy volunteer knees

T. Shiomi; Takashi Nishii; Ken Nakata; Satoru Tamura; Hisashi Tanaka; Youichi Yamazaki; Kenya Murase; Hideki Yoshikawa; Nobuhiko Sugano

ObjectiveQuantitative knee cartilage T2 assessment on limited two-dimensional midsagittal or midcoronal planes may be insufficient to assess variations in normal cartilage composition. The purpose of this work was to reveal characteristic 3D distribution of T2 values in femoral cartilage in healthy volunteer knees.Materials and methodsSixteen volunteers were enrolled in this study. One knee joint in each volunteer was imaged using a 3D fast image employing steady-state acquisition cycled phases (FIESTA-C) sequence for modeling distal femoral morphology, as well as a sagittal T2 mapping of cartilage. 3D distribution of cartilage T2 values was generated for the femoral condyles. At each medial and lateral condyle, four regions of interest (ROI) were manually defined based on the cartilage covered by the 3D surface model of the medial and lateral menisci.ResultsThe 3D maps showed a relatively inhomogeneous distribution of cartilage T2 on the medial and lateral condyles. Cartilage T2 values in the internal half of the weight-bearing zone were significantly higher than those in all other zones on both lateral and medial condyles.ConclusionsAnalysis of 3D distribution of femoral cartilage T2 may be valuable in determining the site-specific normal range of cartilage T2 in the healthy knee joint.


Journal of Arthroplasty | 2014

Spinal Factors Influencing Change in Pelvic Sagittal Inclination From Supine Position to Standing Position in Patients Before Total Hip Arthroplasty

Satoru Tamura; Masaki Takao; Takashi Sakai; Takashi Nishii; Nobuhiko Sugano

In some atypical patients, pelvic sagittal inclination (PSI) changes posteriorly by >10° from supine to standing position before total hip arthroplasty (THA). Several studies have suggested PSI in standing position is related to lumbar degeneration. The purpose of this study was to investigate spinal factors influencing changes in PSI from supine to standing position before THA. Participants comprised 163 consecutive patients who had undergone THA. Presence of compression fractures, presence of lumbar spondylolisthesis, thoracic kyphosis angle, lumbar lordosis angle, S1 anterior tilt angle and T4 plumb line position were investigated as spinal factors. Presence of compression fractures, age, presence of lumbar spondylolisthesis and small S1 anterior tilt angle were independently associated with posterior change in PSI from supine to standing position in patients before THA.


Bioorganic & Medicinal Chemistry Letters | 2010

New inhibitors for expression of IgE receptor on human mast cell

Satoru Tamura; Kunichika Yoshihira; Katsuaki Fujiwara; Nobutoshi Murakami

Exploration for inhibitors against expression of IgE receptor (Fc epsilonRI) on human mast cell, a significant trigger to acute and chronic allergic symptoms, disclosed epigallocatechin gallate (EGCG), epicatechin gallate, and gallocatechin gallate as active principles. Additionally, the anthocyanidin, delphinidin, and the flavone, tricetinidin, possessing a pyrogallol function were also revealed to suppress expression of Fc epsilonRI. Structure-activity relationship analysis among catechins, anthocyanidins, and flavones revealed the pyrogallol moiety to be crucial for biological potency. Furthermore, EGCG was clarified to reduce generation of gamma-chain subunit to suppress expression of Fc epsilonRI on human mast cells.


Tetrahedron | 2001

Synthesis of stable analogs in blood and conformational analysis of arenastatin A, a potent cytotoxic spongean depsipeptide

Nobutoshi Murakami; Satoru Tamura; Weiqi Wang; Tatsuya Takagi; Motomasa Kobayashi

Abstract In order to produce stable analogs in blood of arenastatin A, a potent cytotoxic depsipeptide from the marine sponge Dysidea arenaria , we synthesized four analogs in which the 15-20 ester linkage was modified. Among them, the carba analog and 20-deoxo analog showed stability in serum. The conformation of arenastatin A and its three analogs were analyzed by distance-restrained molecular dynamic calculation to elucidate a three-dimensional stereostructure contributing to the extremely potent cytotoxicity of arenastatin A.


Tetrahedron | 2000

Synthesis of Amide Analogs of Arenastatin A

Nobutoshi Murakami; Weiqi Wang; Naoki Ohyabu; Takeshi Ito; Satoru Tamura; Shunji Aoki; Motomasa Kobayashi; Isao Kitagawa

Abstract In order to probe the metabolism of arenastatin A, a potent cytotoxic depsipeptide from the marine sponge Dysidea arenaria, we synthesized three analogs in which the ester linkages were replaced by amide bonds. Triamide analog-II and tetraamide analog, both of which contained a 15,20-amide linkage, showed stability in serum. However, arenastatin A and triamide analog-I, which both contained a 15,20-ester moiety, were readily metabolized in serum. Among the three amide analogs, only triamide analog-II exhibited potent cytotoxic activity against KB cells.


Bioorganic & Medicinal Chemistry Letters | 2010

Bioisostere of valtrate, anti-HIV principle by inhibition for nuclear export of Rev

Satoru Tamura; Nobuhiro Shimizu; Katsuaki Fujiwara; Masafumi Kaneko; Tominori Kimura; Nobutoshi Murakami

Rational design by the MO calculation disclosed 5,6-dihydrovaltrate (2) as the bioisostere of valtrate (1), the Rev-export inhibitor with anti-HIV activity. The synthesis of 2 was accomplished by ingenious use of asymmetric Diels-Alder reaction and stereoselective epoxidation associated with the adjacent hydroxyl group. Because of similar biological potency to 1, the analog 2 should be recognized as a promising scaffold for new anti-HIV agents with an unprecedented mechanism of action, inhibition for nuclear export of Rev protein, in the conventional remedy.


Bioorganic & Medicinal Chemistry Letters | 2010

Tellimagrandin I, HCV invasion inhibitor from Rosae Rugosae Flos

Satoru Tamura; Gang-Ming Yang; Natsuko Yasueda; Yoshiharu Matsuura; Yasumasa Komoda; Nobutoshi Murakami

By use of the model virus, expressing the HCV envelope proteins E1 and E2, bioassay guided separation of the MeOH extract from Rosa rugosa Thunb. disclosed tellimagrandin I (1) together with eugeniin (2) and casuarictin (3) as the potent HCV invasion inhibitors. Furthermore, structure-activity relationship analysis of some relative tannins including the synthesized analogs elucidated the partial structures crucial for potent activity of 1.


Bioorganic & Medicinal Chemistry Letters | 2000

Synthesis and biological property of carba and 20-deoxo analogues of arenastatin A.

Nobutoshi Murakami; Weiqi Wang; Satoru Tamura; Motomasa Kobayashi

The carba analogue, in which a methylene group is substituted for the oxygen atom linked to C-15, and 20-deoxo analogue of arenastatin A, a potent cytotoxic spongean depsipeptide, were synthesized. Both analogues lacking the 15,20-ester function, which was easily metabolized in serum, showed good stability in serum as well as moderate cytotoxic activity against KB cells and better solubility.

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Hiroshi Shimoda

Kyoto Pharmaceutical University

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