Lead Chemical Co.

Toyama-shi, Japan

Lead Chemical Co.

Toyama-shi, Japan
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Yin S.,University of Toyama | Sugimoto K.,University of Toyama | Nemoto H.,Lead Chemical Co. | Matsuya Y.,University of Toyama
Heterocycles | Year: 2017

For a construction of potential scaffold of antitumor agents andrastins, intramolecular Diels-Alder reaction of the triene composed of trans-fused AB ring with tethered D ring was examined. The reaction in refluxing toluene afforded a desired cis-fused hydrindane skeleton, the relative stereochemistries of which were unambiguously determined by X-ray crystallographic analysis. ©2017 The Japan Institute of Heterocyclic Chemistry.

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.

Kikuchi A.,Yokohama National University | Saito H.,Lead Chemical Co. | Mori M.,Lead Chemical Co. | Yagi M.,Yokohama National University
Photochemical and Photobiological Sciences | Year: 2011

Phosphorescence spectra of nonphosphorescent or very weakly phosphorescent new UV absorbers, 2-methylphenyl cinnamate (MePC), 2-methylphenyl 4-methoxycinnamate (MePMC) and 2-methylphenyl 4-ethoxycinnamate (MePEC) have been observed by using external heavy atom effects of ethyl iodide in ethanol at 77 K. The lowest excited triplet (T 1) energies of these new UV absorbers are lower than those of a widely used UV-A absorber, 4-tert-butyl-4′-methoxydibenzoylmethane (BM-DBM), in both keto and enol forms. The intermolecular triplet-triplet energy transfer from photolabile BM-DBM to MePMC was observed by measuring the time-resolved phosphorescence spectra. Electron paramagnetic resonance spectra have been observed for the T 1 states of these new UV absorbers in ethanol at 77 K by using benzophenone as a triplet sensitizer. The observed T 1 lifetimes, zero-field splitting (ZFS) parameters and molecular orbital calculations of the ZFS parameters suggest that T 1 states of these new UV absorbers posses mainly 3ππ* character. The deactivation processes of the lowest excited singlet (S 1) states are predominantly fluorescence and internal conversion to the ground (G) states in MePMC and MePEC, while the main deactivation process of the S 1 state of MePC is internal conversion to the G state. The molar absorption coefficients of MePMC and MePEC in the UV-A and UV-B regions are larger than that of most widely used UV-B absorber, octyl methoxycinnamate. © 2011 The Royal Society of Chemistry and Owner Societies.

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.

Lead Chemical Co. and Shionogi & Co. | Date: 2011-08-24

There is provided an adhesive preparation containing 5-methyl-1-phenyl-2-(1H)-pyridone. The adhesive preparation is a 5-methyl-1-phenyl-2-(1H)-pyridone-containing adhesive preparation including an active medicinal ingredient-containing layer, characterized in that the active medicinal ingredient-containing layer contains an lipophilic base, a dissolving agent (except glycerin and a medium-chain aliphatic acid triglyceride), and 5-methyl-1-phenyl-2-(1H)-pyridone or medically acceptable salts thereof.

Lead Chemical Co. | Date: 2010-11-24

There is provided a neuronal cell death inhibitor having a high efficacy. A neuronal cell death inhibitor comprising a compound of general formula (1) below:^(1) is a hydrogen atom or an optionally substituted hydroxy group; R^(2) is a hydrogen atom; R^(3) is a hydrogen atom or an optionally substituted hydroxy group; R^(4) is a hydrogen atom or an optionally substituted hydroxy group, R^(3) together with R^(4) is optionally an oxo group or a group of -O-(CH_(2))_(n)-O- (where n is an integer of 2 to 4), or R^(7) together with R^(4) optionally forms an unsaturated bond between carbon atoms, the respective carbon atoms being attached to R^(2) and R^(4); R^(5) is a hydrogen atom or an optionally substituted lower alkyl group; each of R^(6), R^(7), and R^(8) is the same as or different from each other and is a hydrogen atom, an optionally substituted hydroxy group, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group); or a salt thereof.

Lead Chemical Co. | Date: 2010-06-02

There is provided an ultraviolet absorber having a strong absorptive capacity in the UVA range and an absorptive capacity in the UVB range to have an ultraviolet inhibitory effect in a wide range of wavelength, increasing in an ultraviolet absorptive capacity over the course of ultraviolet irradiation time in both the UVA and the UVB ranges and having an excellent solubility. An ultraviolet absorber comprising, as an active ingredient, a compound of General Formula I:

Lead Chemical Co. | Date: 2012-06-13

There is provided a novel compound having neurite-outgrowing activity that is useful for the prevention or the treatment of a neurodegenerative disease. A compound of Formula (I)_(1)R_(2), Y is OH, NR_(3)R_(4), -NHC(=NH)NHR_(5), or -NHC(=NH)R_(5), and Z is a hydrogen atom, a linear or branched C_(1-5) alkyl group, or a 5- or 6-membered ring aryl group optionally having 1 or 2 nitrogen atom(s), sulfur atom(s), or oxygen atom(s)], or a pharmaceutically or veterinary-medically acceptable salt of the compound.

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