51
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Fukuyama K, Ohrui H, Kuwahara S. Synthesis of EFdA via a Diastereoselective Aldol Reaction of a Protected 3-Keto Furanose. Org Lett 2015; 17:828-31. [DOI: 10.1021/ol5036535] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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52
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Abstract
Abstract
The first synthesis of the racemate of terpendole E, a specific inhibitor of the mitotic kinesin Eg5, has been achieved from a known tricyclic dihydroxy ketone by a 13-step sequence that involves diastereoselective installation of its C3 quaternary stereocenter via a cyclopropyl ketone intermediate and Pd-mediated two-step construction of the indole ring moiety as the key transformations.
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53
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Saito A, Igarashi W, Furukawa H, Yamada T, Kuwahara S, Kiyota H. Facile synthesis of the cyclohexane fragment of enacloxins, a series of antibiotics isolated from Frateuria sp. W-315. Biosci Biotechnol Biochem 2014; 78:766-9. [PMID: 25035977 DOI: 10.1080/09168451.2014.905192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
An efficient and good yield synthesis of the cyclohexane moiety of enacyloxins, a series of antibiotics isolated from Frateuria sp. W-315, was achieved from d-quinic acid using a successive Barton-McCombie deoxygenation.
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54
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Kiyota H, Nakashima D, Kuwahara S, Oritani T. Enzymatic Resolution of (±)-2-Exo-7- syn-7-(1-propynyl)norbornan-2-ol, a Key Synthetic Intermediate for Jasmonoids. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2014. [DOI: 10.1515/znb-2008-1217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Lipase-catalyzed resolution of 2-exo-7-syn-7-(1′-propynyl) norbornan-2-ol, a key synthetic intermediate for jasmonoids, was achieved using vinyl chloroacetate as an acyl donor.
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55
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Towada R, Kuwahara S. Synthesis of topsentolides A2 and C2, and non-enzymatic conversion of the former to the latter. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.04.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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56
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Murakami A, Kuwahara S, Takahashi Y, Ito C, Furukawa H, Ju-Ichi M, Koshimizu K. In Vitro Absorption and Metabolism of Nobiletin, a Chemopreventive Polymethoxyflavonoid in Citrus Fruits. Biosci Biotechnol Biochem 2014; 65:194-7. [PMID: 11272829 DOI: 10.1271/bbb.65.194] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The polymethoxyflavonoid (PMF), nobiletin (NOB), specifically occurs in citrus fruits, and is currently believed to be a promising anti-inflammatory and antitumor promoting agent. In the present study, we investigated the in vitro absorption and metabolism of NOB and compared them with those of the polyhydroxyflavonoid (PHF), luteolin (LT). NOB preferentially accumulated in a differentiated Caco-2 cell monolayer, which is a model for small intestinal epithelial cells, while LT did not. Treatment of NOB with a rat liver S-9 mixture led to the formation of 3'-demethyl-NOB, while that of LT did not. We thus suggest that PMFs including NOB have properties distinct from those of general flavonoids for absorption and metabolism in vitro.
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57
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Morita A, Kiyota H, Kuwahara S. Enantioselective Synthesis of the (1S,5R)-Enantiomer of Litseaverticillols A and B. Biosci Biotechnol Biochem 2014; 70:2564-6. [PMID: 17031060 DOI: 10.1271/bbb.60253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An enantioselective synthesis of the (1S,5R)-enantiomer of litseaverticillols A and B was accomplished in line with our previously reported synthetic pathway for their (1R,5S)-enantiomer. The use of "EtSCeCl2" prepared from EtSLi and CeCl3, instead of previously employed EtSLi itself, for the formation of thiol ester intermediates prevented any undesirable epimerization occurring in the process.
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58
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Miyagi T, Kuwahara S. A Concise Synthetic Approach to β,γ-Dehydrocurvularin: Synthesis of (±)-Di-O-Methyl-β,γ-dehydrocurvularin. Biosci Biotechnol Biochem 2014; 71:1592-4. [PMID: 17587698 DOI: 10.1271/bbb.70094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A concise synthesis of di-O-methyl-beta,gamma-dehydrocurvularin, the di-O-methylated derivative of the naturally occurring nematicidal macrolide, beta,gamma-dehydrocurvuralin, was accomplished by starting from a commercially available aromatic carboxylic acid in a three-step sequence consisting of esterification, Friedel-Crafts acylation, and microwave-promoted ring-closing metathesis.
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59
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Morita A, Matsuyama S, Oguma Y, Kuwahara S. Simple Synthesis of the Major Sex Pheromone Components ofDrosophila ananassaeandD. pallidosa. Biosci Biotechnol Biochem 2014; 69:1620-3. [PMID: 16116297 DOI: 10.1271/bbb.69.1620] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The major sex pheromone components of Drosophila ananassae and D. pallidosa, (Z,Z)-5,25-hentriacontadiene and (Z,Z)-5,27-tritriacontadiene, respectively, were synthesized by using the Wittig olefination and sulfone coupling reactions as the C-C bond-forming steps.
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60
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Katayama K, Takeda Y, Shimaoka K, Yoshida K, Shimizu R, Ishiwata T, Nakamura A, Kuwahara S, Mase A, Sugita T, Mori M. Novel method of screening the oxidation and reduction abilities of photocatalytic materials. Analyst 2014; 139:1953-9. [DOI: 10.1039/c3an02167j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A methodology for understanding the photocatalytic abilities of materials is presented. The conversion of simple organic molecules was monitored in situ in photocatalytic microreactors.
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61
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Osada N, Oshima T, Kuwahara S, Toyoda T, Shen Q, Katayama K. Photoexcited carrier dynamics of double-layered CdS/CdSe quantum dot sensitized solar cells measured by heterodyne transient grating and transient absorption methods. Phys Chem Chem Phys 2014; 16:5774-8. [DOI: 10.1039/c3cp55177f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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62
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Fujii T, Kuwahara S, Katayama K, Takado K, Ube T, Ikeda T. Molecular dynamics in azobenzene liquid crystal polymer films measured by time-resolved techniques. Phys Chem Chem Phys 2014; 16:10485-90. [DOI: 10.1039/c4cp00457d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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63
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Saito A, Hiramatsu K, Cao HQ, Nagashima Y, Tanaka K, Sasaki A, Yamada T, Kuwahara S, Nukina M, Kiyota H. 5-(2,2-Dimethyl-4H-1,3-benzodioxin)methanol: the synthetic precursor to o-formyl-m-hydroxycinnamic acid, the most oxidized salicylaldehyde-type phytotoxin isolated from rice blast fungus, Magnaporthe grisea. HETEROCYCL COMMUN 2014. [DOI: 10.1515/hc-2014-0053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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64
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Shoji M, Nakagawa K, Watanabe A, Tsuduki T, Yamada T, Kuwahara S, Kimura F, Miyazawa T. Comparison of the effects of curcumin and curcumin glucuronide in human hepatocellular carcinoma HepG2 cells. Food Chem 2013; 151:126-32. [PMID: 24423511 DOI: 10.1016/j.foodchem.2013.11.021] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/27/2013] [Accepted: 11/04/2013] [Indexed: 10/26/2022]
Abstract
Curcumin is a yellow pigment found in turmeric (Curcuma Longa L.), and is reported, in recent studies, to have several pharmacological effects, including anti-oxidant, anti-inflammatory, anti-tumour and lipid-lowering properties. However, as most curcumin is conjugated when absorbed through the intestine, free curcumin is present at extremely low levels inside the body. Therefore, curcumin metabolites have been presumed to be responsible for the curcumin bioactivity. In this study, we first confirmed that curcumin glucuronide is the major metabolite of curcumin found in the plasma after oral administration of curcumin in rats. Next, we synthesised curcumin glucuronide and compared the effects of curcumin and curcumin glucuronide on gene expression in a human hepatoma cell line (HepG2). We found that the effects of curcumin glucuronide are weaker than those of curcumin and that this difference is related to relative absorption rates of curcumin and curcumin glucuronide into HepG2 cells.
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65
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66
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Hirokawa T, Kuwahara S. Enantioselective Synthesis of Hushinone, Birkenol, and Birkenal. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300257] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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67
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Horii S, Torihata M, Nagasawa T, Kuwahara S. Stereoselective Approach to the Racemic Oxatetracyclic Core of Platensimycin. J Org Chem 2013; 78:2798-801. [DOI: 10.1021/jo302813y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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68
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Enomoto M, Morita A, Kuwahara S. Total Synthesis of the Tremorgenic Indole Diterpene Paspalinine. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201206299] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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69
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Enomoto M, Morita A, Kuwahara S. Total synthesis of the tremorgenic indole diterpene paspalinine. Angew Chem Int Ed Engl 2012; 51:12833-6. [PMID: 23135880 DOI: 10.1002/anie.201206299] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/10/2012] [Indexed: 11/05/2022]
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70
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Ueda M, Yang G, Ishimaru Y, Itabashi T, Tamura S, Kiyota H, Kuwahara S, Inomata S, Shoji M, Sugai T. Hybrid stereoisomers of a compact molecular probe based on a jasmonic acid glucoside: Syntheses and biological evaluations. Bioorg Med Chem 2012; 20:5832-43. [DOI: 10.1016/j.bmc.2012.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 08/03/2012] [Accepted: 08/04/2012] [Indexed: 11/30/2022]
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71
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72
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Hirokawa T, Nagasawa T, Kuwahara S. Enantioselective synthesis of rumphellaone A via epoxy nitrile cyclization. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2011.11.145] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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73
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74
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Kiyota H, Takai K, Hanadate T, Oi S, Yamada T, Kuwahara S. Synthesis of Both Enantiomers of ω-Trifluorononactic Acid, a New Analogue of Nonactin Monomers. SYNTHESIS-STUTTGART 2011. [DOI: 10.1055/s-0030-1260234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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75
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Tanaka K, Sasaki A, Cao HQ, Yamada T, Igarashi M, Komine I, Nakahigashi H, Minami N, Kuwahara S, Nukina M, Kiyota H. Synthesis and Biotransformation of Plausible Biosynthetic Intermediates of Salicylaldehyde-Type Phytotoxins of Rice Blast Fungus, Magnaporthe grisea. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100771] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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