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Dive into the research topics where Shinsuke Marumoto is active.

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Featured researches published by Shinsuke Marumoto.


Phytotherapy Research | 2009

β-Secretase inhibitory effects of furanocoumarins from the root of Angelica dahurica.

Shinsuke Marumoto; Mitsuo Miyazawa

In the course of screening antidementia agents from natural products, five β‐secretase (BACE1) inhibitors were isolated from the root extract of Angelica dahurica (Umbelliferae). They were identified as furanocoumarins, isoimperatorin (1), imperatorin (2), (+)‐oxypeucedanin (3), (+)‐byakangelicol (4) and (+)‐byakangelicin (5). Among them, compounds 2 and 4 showed significant inhibitory activity against β‐secretase (BACE1) with IC50 values of 91.8 ± 7.5 and 104.9 ± 2.4 μM, respectively. Compounds 1‐5 inhibited BACE1 activity in a dose‐dependent manner. Copyright


Bioorganic & Medicinal Chemistry | 2012

Structure-activity relationships for naturally occurring coumarins as β-secretase inhibitor.

Shinsuke Marumoto; Mitsuo Miyazawa

The present study was demonstrated to evaluate the effects of naturally occurring coumarins (NOCs) including simple coumarins, furanocoumarins, and pyranocoumarins on the inhibition of β-secretase (BACE1) activity. Of 41 NOCs examined, some furanocoumarins inhibited BACE1 activity, but simple coumarins and pyranocoumarins did not affect. The most potent inhibitor was 5-geranyloxy-8-methoxypsoralen (31), which has an IC(50) value of 9.9 μM. Other furanocoumarin derivatives, for example, 8-geranyloxy-5-methoxypsoralen (35), 8-geranyloxypsoralen (24), and bergamottin (18) inhibited BACE1 activity, with the IC(50) values <25.0 μM. Analyses of the inhibition mechanism by Dixon plots and Cornish-Bowden plots showed that compounds 18, 31 and 35 were mixed-type inhibitor. The kinetics of inhibition of BACE1 by coumarins 24 was non-competitive inhibitors.


Bioorganic & Medicinal Chemistry | 2010

Biotransformation of isoimperatorin and imperatorin by Glomerella cingulata and β-secretase inhibitory activity

Shinsuke Marumoto; Mitsuo Miyazawa

Biotransformation studies conducted on the furanocoumarins isoimperatorin (1) and imperatorin (3) have revealed that 1 was metabolized by Glomerella cingulata to give the corresponding reduced acid, 6,7-furano-5-prenyloxy hydrocoumaric acid (2), and 3 was transformed by G. cingulata to give the dealkylated metabolite, xanthotoxol (4) in high yields (83% and 81%), respectively. The structures of the new compound 2 have been established on the basis of spectral data. The metabolites 2 and 4 were tested for the beta-secretase (BACE1) inhibitory activity in vitro, and metabolite 2 slightly inhibited the beta-secretase activity with an IC(50) value of 185.6+/-6.8 microM. The metabolite 4 was less potent activity than compounds 1-3. In addition, methyl ester (2Me), methyl ether (2a) and methyl ester and ether (2aMe) of 2 were synthesized, and investigated for the ability to inhibit beta-secretase. Compound 2aMe exhibited the best beta-secretase inhibitory activity at the IC(50) value 16.2+/-1.2 microM and found to be the 2aMe showed competitive mode of inhibition against beta-secretase with K(i) value 11.3+/-2.8 microM.


Journal of Agricultural and Food Chemistry | 2010

Biotransformation of bergapten and xanthotoxin by Glomerella cingulata.

Shinsuke Marumoto; Mitsuo Miyazawa

The biotransformation of bergapten (1) by the fungus Glomerella cingulata gave the corresponding reduced acid, 6,7-furano-5-methoxy hydrocoumaric acid (2), a new compound. Xanthotoxin (3) was also converted to the corresponding reduced acid cnidiol b (4) and demethylated metabolite xanthotoxol (5) by G. cingulata. The structure of the new compound 2 was elucidated by high-resolution mass spectrometry, extensive NMR techniques, including (1)H NMR and (13)C NMR, (1)H-(1)H correlation spectroscopy, heteronuclear multiple quantum coherence, and heteonuclear multiple bond coherence. The methyl ester or methyl ether or methyl ester and ether derivatives of 2 and 4 were synthesized. All compounds were tested for the beta-secretase (BACE1) inhibitory activity in vitro. The methyl ester and ether derivative 8 was shown to possess BACE1 inhibitory activity, and a IC(50) value was 0.64 +/- 0.04 mM.


Environmental and Molecular Mutagenesis | 2011

Antigenotoxic activity of naturally occurring furanocoumarins.

Shinsuke Marumoto; Yoshimitsu Oda; Mitsuo Miyazawa

This study was designed to investigate the antigenotoxic effects of a series of naturally occurring furanocoumarins (NOFs) including isoimperatorin, imperatorin, (+)‐oxypeucedanin, (+)‐byakangelicol, and (+)‐byakangelicine on antigenotoxic activities against genotoxicity induced by carcinogens [furylfuramide and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine], and procarcinogens 2‐[2‐(acetylamino)−4‐amino‐5‐methoxyphenyl]−5‐amino‐7‐bromo‐4‐chloro‐2H‐benzotriazole (PBTA‐4) and 2‐amino‐3,4‐dimethyl‐3H‐imidazo‐[4,5‐f] quinoline (MeIQ)] to genotoxic metabolites catalyzed by rat S9 or rat and human recombinant cytochrome P450 (CYP) 1As by using the umu test based on SOS response. Five different NOFs, which were found in the human diets, strongly inhibited the umuC induction by procarcinogens, but did not be affected by carcinogens. Notably, isoimperatorin and (+)‐byakangelicol were found to be potent inhibitors on the metabolic activation of PBTA‐4 and MeIQ to genotoxic metabolites catalyzed by rat and human CYP1A1, or rat and human CYP1A2, respectively. In addition, to elucidate the mechanism of their antigenotoxic effects against procarcinogens, the effects of NOFs on rat and human CYP1A1‐ or rat and human CYP1A2‐related enzyme activities of 7‐ethoxyresorufin‐O‐deethylase (EROD) were also investigated. Reduction of the EROD activities by some of the NOFs with IC50 values of 0.23–20.64 μM was found to be due to strong inhibition of CYP1A1 and CYP1A2 dependent monooxygenases. Furthermore, the mechanism of inhibitions by NOFs on human CYP1A1 and CYP1A2 was analyzed by means of Dixon plots plus Cornish‐Bowden plots. The kinetic studies of inhibition types revealed that these compounds inhibited the human CYP1A1 and CYP1A2 a variety of modes rather than by a uniform one. Moreover, experiments with a two‐stage incubation indicated that NOFs, except for imperatorin, inhibited human CYP1A1 in a mechanism‐based manner, but directly inhibited human CYP1A2. This data suggest that certain NOFs, to which humans are exposed in the diet, may be capable of affecting the metabolic activation of procarcinogens due to inhibitions of CYP1A1 and CYP1A2 enzymes. Environ. Mol. Mutagen., 2011.


Journal of Natural Products | 2011

Biotransformation of turmerones by Aspergillus niger.

Mai Fujiwara; Shinsuke Marumoto; Nobuo Yagi; Mitsuo Miyazawa

Biotransformation studies conducted on (+)-(S)-ar-turmerone (1) and (+)-(S)-dihydro-ar-turmerone (2) by the fungus Aspergillus niger have revealed that 1 was metabolized to give four oxidized metabolites, (+)-(7S)-hydroxydehydro-ar-todomatuic acid (3), (+)-(7S,10E)-12-hydroxydehydro-ar-todomatuic acid (4), (+)-(7S,10E)-7,12-dihydroxydehydro-ar-todomatuic acid (5), and (+)-(7S)-15-carboxy-9,13-epoxy-7-hydroxy-9,13-dehydro-ar-curcumene (6), and (+)-(S)-dihydro-ar-turmerone (2) was metabolized to (+)-7,11-dihydroxy-ar-todomatuic acid (7). Metabolites 3-7 were characterized using spectroscopic techniques. Metabolites 3-7 inhibited acetylcholinesterase (AChE) although less so than the parent substrates.


Phytochemical Analysis | 2014

Aroma Evaluation of Setonojigiku (Chrysanthemum japonense var. debile) by Hydrodistillation and Solvent‐assisted Flavour Evaporation

Atsushi Usami; Hiroshi Nakahashi; Shinsuke Marumoto; Mitsuo Miyazawa

INTRODUCTION The Chrysanthemum genus consisting of about 200 species is mainly distributed over the Northern Hemisphere. Despite the pleasant odour of C. japonense var. debile (setonojigiku), no detailed analysis of the aroma-active compounds has been reported using sensory evaluation. OBJECTIVES Using a hydrodistillation (HD) and a solvent-assisted flavour evaporation (SAFE) method to obtain the volatile oil from the leaf parts. METHODS To clarify odorants contributing to the characteristic aroma-active compounds, the aroma-extract dilution analysis (AEDA) method was performed through gas chromatography olfactometry (GC/O) analysis. In addition, the odour activity value (OAV) was calculated in order to determine the relative contribution of each compound to the aroma-active compounds. RESULTS A total of 42 components by HD oil were identified by GC-MS, whereas 34 components were identified in SAFE oil. Thirteen compounds were identified by GC/O analysis in HD and SAFE oils respectively. CONCLUSION Each extraction method has its own advantages and disadvantages, and they are generally complementary to each other. On the basis of AEDA, OAV and sensory evaluations, [2.2.1] bicyclic monoterpenes (borneol, bornyl acetate and camphor) and β-caryophyllene are considered to be the main aroma-active compounds of both extraction methods.


Chemistry & Biodiversity | 2015

Chemical Composition and Character Impact Odorants in Volatile Oils from Edible Mushrooms

Atsushi Usami; Ryota Motooka; Hiroshi Nakahashi; Shinsuke Marumoto; Mitsuo Miyazawa

The aim of this study was to investigate the chemical composition and the odor‐active components of volatile oils from three edible mushrooms, Pleurotus ostreatus, Pleurotus eryngii, and Pleurotus abalonus, which are well‐known edible mushrooms. The volatile components in these oils were extracted by hydrodistillation and identified by GC/MS, GC‐olfactometry (GC‐O), and aroma extract dilution analysis (AEDA). The oils contained 40, 20, and 53 components, representing 83.4, 86.0, and 90.8% of the total oils in P. ostreatus, P. eryngii, and P. abalonus, respectively. Odor evaluation of the volatile oils from the three edible mushrooms was also carried out using GC‐O, AEDA, and odor activity values, by which 13, eight, and ten aroma‐active components were identified in P. ostreatus, P. eryngii, and P. abalonus, respectively. The most aroma‐active compounds were C8‐aliphatic compounds (oct‐1‐en‐3‐ol, octan‐3‐one, and octanal) and/or C9‐aliphatic aldehydes (nonanal and (2E)‐non‐2‐enal).


Journal of Oleo Science | 2017

Inhibition of β-Secretase Activity by Monoterpenes, Sesquiterpenes, and C13 Norisoprenoids

Shinsuke Marumoto; Yoshiharu Okuno; Mitsuo Miyazawa

Inhibition of β-secretase (BACE1) is currently regarded as the leading treatment strategy for Alzheimers disease. In the present study, we aimed to screen the in vitro inhibitory activity of 80 types of aroma compounds (monoterpenes, sesquiterpenes, and C13 norisoprenoids), including plant-based types, at a 200-μM concentration against a recombinant human BACE1. The results showed that the most potent inhibitor of BACE1 was geranyl acetone followed by (+)-camphor, (-)-fenchone, (+)-fenchone, and (-)-camphor with the half-maximal inhibitory concentration (IC50) values of 51.9 ± 3.9, 95.9 ± 11.0, 106.3 ± 14.9, 117.0 ± 18.6, and 134.1 ± 16.4 μM, respectively. Furthermore, the mechanism of inhibition of BACE1 by geranyl acetone was analyzed using Dixon kinetics plus Cornish-Bowden plots, which revealed mixed-type mode. Therefore aroma compounds may be used as potential lead molecules for designing anti-BACE1 agents.


Journal of Oleo Science | 2015

Characteristic odor components of essential oils from Eurya japonica.

Ryota Motooka; Atsushi Usami; Hiroshi Nakahashi; Satoshi Koutari; Satoshi Nakaya; Ryoyu Shimizu; Kaoru Tsuji; Shinsuke Marumoto; Mitsuo Miyazawa

The chemical compositions of essential oils from the flower and aerial parts (i.e., leaf and branch) of Eurya japonica were determined and quantified using gas chromatography-mass spectrometry (GC-MS). A total of 87 and 50 compounds were detected in the oils from the flower and aerial parts, respectively. The main compounds of the flower oil were linalool (14.0%), (9Z)-tricosene (12.0%), and nonanal (7.4%). In the oil from the aerial parts, linalool (37.7%), α-terpineol (13.5%), and geraniol (9.6%) were detected. In the oils from the flower and aerial parts, 13 and 8 aroma-active compounds were identified by GC-olfactometry (GC-O) analysis, respectively. The key aroma-active compounds of the flower oil were heptanal [fatty, green, flavor dilution (FD) = 128, odor activity value (OAV) = 346], nonanal (sweet, citrus, FD = 128, OAV = 491), and eugenol (sweet, spicy, FD = 64, OAV = 62): in the oil from the aerial parts, the key aroma-active compounds were linalool (sweet, citrus, FD = 64, OAV = 95), (E)-β-damascenone (sweet, FD = 256, OAV = 4000), and (E)-β-ionone (floral, violet, FD = 128, OAV = 120). This study revealed that nonanal and eugenol impart the sweet, citrus, and spicy odor of the flower oil, while (E)-β-damascenone and (E)-β-ionone contribute the floral and sweet odor of the oil from the aerial parts.

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