- Pilot in Vivo Structure-Activity Relationship of Dihydromethysticin in Blocking 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone-Induced O6-Methylguanine and Lung Tumor in A/J Mice
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(+)-Dihydromethysticin was recently identified as a promising lung cancer chemopreventive agent, while (+)-dihydrokavain was completely ineffective. A pilot in vivo structure-activity relationship (SAR) was explored, evaluating the efficacy of its analogs in blocking 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced short-term O6-methylguanine and long-term adenoma formation in the lung tissues in A/J mice. Both results revealed cohesive SARs, demonstrating that the methylenedioxy functional group in DHM is essential while the lactone functional group tolerates modifications.
- Puppala, Manohar,Narayanapillai, Sreekanth C.,Leitzman, Pablo,Sun, Haifeng,Upadhyaya, Pramod,O'Sullivan, M. Gerard,Hecht, Stephen S.,Xing, Chengguo
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p. 7935 - 7940
(2017/10/06)
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- Heck-matsuda arylation as a strategy to access kavalactones isolated from polygala sabulosa, piper methysticum, and analogues
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Herein, we describe the total syntheses of three bioactive pyrones isolated from Polygala sabulosa (i.e., 1, 4, and 7) and eight isolated from Piper methysticum (i.e., 8-10, 13, 15, and 18-20) using the Heck-Matsuda arylation as the key strategy. The evaluation of this methodology by employing different arenediazonium tetrafluoroborates revealed that the Heck arylation was more efficient when the olefin undergoing arylation possessed the vinyl-2-pyrone structural unit instead of the vinyl dihydro-2-pyrone moiety. The Heck-Matsuda arylation of many of the examined olefins proceeded in a practical manner with total regio- and stereocontrol.
- Soldi, Cristian,Moro, Angelica V.,Pizzolatti, Moacir G.,Correia, Carlos R. D.
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experimental part
p. 3607 - 3616
(2012/07/31)
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- Synthesis of β-methoxyacrylate natural products based on box-Pd IIcatalyzed intermolecular methoxycarbonylation of alkynoles
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Bis(oxazoline)-palladium(II) catalyzed carbonylation of homopropargyl alcohols afforded acyclic methoxyacrylate 2 and 6-membered lactone 3a-k in good combined yield. In the case of propargyl alcohols, 5-membered lactones 3p, 3q, 16 were obtained in moderate yields. The one-pot synthesis of kawa lactones 3a, 3r, 3s and formal synthesis of dihydroxycystothiazole A and dihydroxycystothiazole C are presented. To elucidate the stereochemistry of (+)-annularin G and (-)-annularin H, the first asymmetric syntheses of these natural products were achieved.
- Motodate, Satoshi,Kobayashi, Takuya,Fujii, Mikio,Mochida, Tomoyuki,Kusakabe, Taichi,Katoh, Shigeki,Akita, Hiroyuki,Kato, Keisuke
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experimental part
p. 2221 - 2230
(2011/06/21)
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- Highly regio- and stereoselective Heck reaction of allylic esters with arenediazonium salts: Application to the synthesis of kavalactones
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Image Presented A highly efficient palladium-catalyzed Heck reaction of allylic esters with arenediazonium salts is described. The reaction proceeds under mild conditions, with excellent to total regio- and stereochemical control and with retention of the traditional leaving group. Furthermore, the generality of the present methodology is illustrated by the short total synthesis of the natural kavalactones, yangonine, (±)-methysticin, and (±)-dihydromethysticin.
- Moro, Angelica Venturini,Cardoso, Flavio Sega Pereira,Correia, Carlos Roque Duarte
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supporting information; experimental part
p. 3642 - 3645
(2011/02/25)
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- Polymer-supported electron-rich diene for hetero Diels-Alder reactions
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A Brassard diene analogue was grafted on a modified Merrifield resin and used in a hetero Diels-Alder reaction with various aldehydes or ketones. The reaction gave access to 6-substituted 5,6-dihydropyrones (5a-u). This new immobilized electron-rich diene is more stable than the corresponding native diene, and is a versatile supported reagent.
- Pierres, Camille,George, Pascal,Van Hijfte, Luc,Ducep, Jean-Bernard,Hibert, Marcel,Mann, André
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p. 3645 - 3647
(2007/10/03)
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