- NEOLIGNANS FROM ANIBA LANCIFOLIA
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The branches of the shrub Aniba lancifolia Kubitzki et Rodrigues (Lauraceae) contain besides 2-hydroxy-4,5-dimethoxyallylbenzene and its dimer cyclohexan-2-allyl-5-en-4,5-dimethoxy-4-O-(2'-allyl-4;,5'-dimethoxyphenyl)-1-one (lancilin, 2) 6 further novel n
- Diaz D., Pedro, P.,Yoshida, Massayoshi,Gottlieb, Otto R.
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- Investigating the microwave-accelerated Claisen rearrangement of allyl aryl ethers: Scope of the catalysts, solvents, temperatures, and substrates
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The microwave-accelerated Claisen rearrangement of allyl aryl ethers was investigated, in order to gain insight into the scope of the catalysts, solvents, temperatures, and substrates. Among the catalysts examined, phosphomolybdic acid (PMA) was found to greatly accelerate the reaction in NMP, at temperatures ranging from 220 to 300 °C. This method was found to be useful for preparing several intermediates previously reported in the literature using precious metal catalysts such as Au(I), Ag(I), and Pt(II). Additionally, substrates bearing bromo and nitro groups on the aryl portion required careful tailoring of the reaction conditions to avoid complex product profiles.
- Hui, Zi,Jiang, Songwei,Qi, Xiang,Ye, Xiang-Yang,Xie, Tian
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supporting information
(2020/05/18)
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- Total synthesis of (-)-Haouamine B pentaacetate and structural revision of haouamine B
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The enantiocontrolled total synthesis of (-)-haouamine B pentaacetate was accomplished via an optically active indane-fused β-lactam, which was prepared by a newly developed Friedel-Crafts reaction. Subsequent cleavage of the β-lactam and an intramolecular McMurry coupling reaction provided the core indane-fused tetrahydropyridine, which led to the elucidation of the structure, as proposed by Trauner and Zuba.
- Momoi, Yuichi,Okuyama, Kei-Ichiro,Toya, Hiroki,Sugimoto, Kenji,Okano, Kentaro,Tokuyama, Hidetoshi
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supporting information
p. 13215 - 13219
(2015/01/09)
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- Metabolism of methylisoeugenol in liver microsomes of human, rat, and bovine origin
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Methylisoeugenol (1,2-dimethoxy-4-propenylbenzene, 1) is a minor constituent of essential oils, naturally occurring as a mixture of cis/trans isomers. 1 is a U.S. Food and Drug Administration-approved food additive and has been given "Generally Recognized as Safe" status. Previously, metabolism of 1 has been studied in the rat, revealing mainly nontoxic cinnamoyl derivatives as major metabolites. However, data concerning the possible formation of reactive intermediary metabolites are not available to date. In this study, the oxidative metabolism of 1 was studied using liver microsomes of rat [not induced, rat liver microsomes (RLM); Aroclor1254 induced RLM (ARLM)], bovine, and human (pooled from 150 donors) origin. Incubations of these microsomes with 1 provided phase I metabolites that were separated by high-performance liquid chromatography (HPLC) and identified by NMR and UV-visible spectroscopy and/or liquid chromatography-mass spectrometry. Identity was confirmed by comparison with 1H NMR spectra of synthesized reference compounds. Formation of metabolites was quantified by HPLC/UV using dihydromethyleugenol (10) synthesized as the internal standard. From incubations of ARLM with 1, seven metabolites could be detected, with 3′- hydroxymethylisoeugenol (2), isoeugenol and isochavibetol (3 + 4), and 6-hydroxymethylisoeugenol (5) being the main metabolites. Secondary metabolites derived from 1 were identified as the α,β-unsaturated aldehyde 3′-oxomethylisoeugenol (6) and 1′,2′-dihydroxy- dihydromethylisoeugenol (7). We were surprised to find that formation of allylic 6-hydroxymethyleugenol (8) was observed starting at approximately 30 min after the beginning of incubations with ARLM. HLM did not form ring-hydroxylated metabolites but were most active in the formation of 6 and 7. ARLM incubations displayed the highest turnover rate and broadest metabolic pattern, presumably resulting from an increased expression of cytochrome P450 enzymes. In conclusion, we present a virtually complete pattern of nonconjugated microsomal metabolites of 1 comprising reactive metabolites and suggest the formation of reactive intermediates that need more investigation with respect to their possible adverse properties. Copyright
- Cartus, Alexander T.,Merz, Karl-Heinz,Schrenk, Dieter
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experimental part
p. 1727 - 1733
(2012/03/22)
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- Design, synthesis, and docking of highly hypolipidemic agents: Schizosaccharomyces pombe as a new model for evaluating α-asarone-based HMG-CoA reductase inhibitors
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A series of α-asarone-based analogues was designed by conducting docking experiments with published crystal structures of human HMG-CoA reductase. Indeed, synthesis and evaluation of this series showed a highly hypocholesterolemic in vivo activity in a murine model, as predicted by previous docking studies. In agreement with this model, the polar groups attached to the benzene ring could play a key role in the enzyme binding and probably also in its biological activity, mimicking the HMG-moiety of the natural substrate. The hypolipidemic action mechanism of these compounds was investigated by developing a simple, efficient, and novel model for determining HMG-CoA reductase inhibition. The partial purification of the enzyme from Schizosaccharomyces pombe allowed for testing of α-asarone- and fibrate-based analogues, resulting in positive and significant inhibitory activity.
- Argueelles, Nancy,Sanchez-Sandoval, Eugenia,Mendieta, Aaron,Villa-Tanaca, Lourdes,Garduno-Siciliano, Leticia,Jimenez, Fabiola,Cruz, Maria del Carmen,Medina-Franco, Jose L.,Chamorro-Cevallos, German,Tamariz, Joaquin
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experimental part
p. 4238 - 4248
(2010/09/12)
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- Ring-closing metathesis for the synthesis of 2H- and 4H-chromenes
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Six 4H-chromenes were synthesized from substituted phenols using vinylstannylation and ring-closing metathesis (RCM) as key steps. In addition, a different approach involving amongst other steps, an aryl allyl isomerization and RCM afforded a set of seven 2H-chromenes from phenolic precursors.
- Van Otterlo, Willem A.L.,Ngidi, E. Lindani,Kuzvidza, Samuel,Morgans, Garreth L.,Moleele, Simon S.,De Koning, Charles B.
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p. 9996 - 10006
(2007/10/03)
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- Ring-closing metathesis for the synthesis of benzo-fused bicyclic compounds
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Ring-closing metathesis (RCM) was used to synthesise five 4H-chromenes, a naphthol and an indenol. These are the first examples of RCM applied to the synthesis of such benzo-fused bicyclic compounds.
- Van Otterlo, Willem A.L.,Ngidi, E. Lindani,Coyanis, E. Mabel,De Koning, Charles B.
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p. 311 - 313
(2007/10/03)
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- A biomimetic approach to dihydrobenzofuran synthesis
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A method for an acid-catalyzed construction of dihydrobenzofuran heterocycles (14) from 2-(2′-hydroxyethyl)quinone precursors 10 is presented. The putative oxonium ion intermediate 17 formed by an intramolecular hydroxyl cyclization followed by dehydration is reduced in situ by an added dihydroquinone source. Good to excellent yields of cyclized products are realized in all cases except for highly electron deficient systems, and these suffer reduction prior to oxonium ion formation. All products are monomeric and derived from a two-electron transfer except for 10g, which affords the dimeric dihydrobenzofuran. The amount of cyclization or reduction product is governed by the HOMO/LUMO gap between the quinone substrate and the dihydroquinone additive, and the product distribution can be adjusted by modifying the electronic properties of the added reducing agent.
- Benbow,Katoch-Rouse
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p. 4965 - 4972
(2007/10/03)
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- The Synthesis of Megaphone
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Condensation of 4,4,5-trimethoxy-2-propyl>-2,5-cyclohexadien-1-one (7) with 1,2,3-trimethoxy-5-(1-(Z)-propenyl)benzene in dichloromethane, in the presence of 1 equiv. of stannic chloride, gave (2β,3β,3aα)-3,3a-dihydro-5-methoxy-3-m
- Buechi, George,Chu, Ping-Sun
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p. 2718 - 2721
(2007/10/02)
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