Time filter

Source Type

Toyama-shi, Japan

Sugimoto K.,University of Toyama | Tamura K.,University of Toyama | Ohta N.,University of Toyama | Tohda C.,University of Toyama | And 3 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2012

As a part of our research program on developing novel anti-Alzheimer's disease medicines, several dihydrofuran-fused perhydrophenanthrenes (DFs) possessing a phenolic hydroxyl group were found to exhibit potent dendritic and axonal regeneration activities. Introduction of a methoxy group into the perhydrophenanthrene skeleton was successfully achieved via a PhI(OAc) 2-mediated phenolic oxidation of a benzocyclobutene nucleus and subsequent tandem intramolecular electrocyclic reactions based on o-quinodimethane chemistry. We could reveal that a new methoxy derivative having a phenolic hydroxyl group exerted the most significant effects on the dendritic and axonal extensions in the damaged neurons, among DFs examined in this study. © 2011 Elsevier Ltd. All rights reserved.

Sugimoto K.,University of Toyama | Hayashi R.,University of Toyama | Nemoto H.,Lead Chemical Co. | Toyooka N.,University of Toyama | Matsuya Y.,University of Toyama
Organic Letters | Year: 2012

Efficient monocyclic 1,2-diazepine formation via a tandem electrocyclization reaction of cyclobutenones with lithiodiazoacetate is demonstrated. The reaction proceeds through an oxy anion-accelerated 4π-ring opening of cyclobutene followed by an 8π-ring closure of the resultant oxy anion-substituted diazo-diene under mild conditions to furnish a 1,2-diazepine via formal diazomethylene insertion into the C-C bond of cyclobutenone. © 2012 American Chemical Society.

Minato D.,University of Toyama | Li B.,University of Toyama | Zhou D.,Henan Polytechnic University | Shigeta Y.,University of Toyama | And 5 more authors.
Tetrahedron | Year: 2013

Simplified des-AB-type aglycone of antitumor steroidal saponin OSW-1 was concisely prepared starting from readily available Hajos ketone. We further completed the synthesis of des-AB-OSW-1 analogue by the installation of the disaccharide moiety into the des-AB aglycone, and evaluated its antitumor activity. The results indicated that a truncated aglycone drug design strategy based on OSW-1 would be a promising approach for the development of novel antitumor agents. © 2013 Elsevier Ltd. All rights reserved.

Sugimoto K.,University of Toyama | Tamura K.,University of Toyama | Tohda C.,University of Toyama | Toyooka N.,University of Toyama | And 2 more authors.
Bioorganic and Medicinal Chemistry | Year: 2013

As an extended study on development of anti-Alzheimer's disease agent, we newly synthesized various dihydrofuran-fused perhydrophenanthrenes via o-quinodimethane chemistry. This study revealed that the introduction of carbon side-chain on 8-position or removal of the acetal moiety on 3-position arose a cytotoxicity on rat cortical neurons. On the other hand, the ethereal or thio-ethereal substituent on 8-position enhanced the elongation effect on Aβ-damaged neurons. The necessity of the cyano group on 10b position was also proved in this structure-activity-relationship study. © 2013 Published by Elsevier Ltd.

Sugimoto K.,University of Toyama | Kobayashi Y.,University of Toyama | Hori A.,University of Toyama | Kondo T.,University of Toyama | And 3 more authors.
Tetrahedron | Year: 2011

Syntheses of 16-membered macrolactams, which were aza-analogues of macrosphelides, could be established effectively by a ring-closing metathesis (RCM) strategy. Novel 19 analogues and six aza-macrosphelide-epothilone hybrids were furnished according to simple operations. Biological assay of these artificial aza-macrosphelides revealed that some of them showed stronger apoptosis-inducing activity against human lymphoma cells than the parent compound. © 2011 Elsevier Ltd. All rights reserved.

Discover hidden collaborations