- Natural α-methylenelactam analogues: Design, synthesis and evaluation of α-alkenyl-γ and δ-lactams as potential antifungal agents against Colletotrichum orbiculare
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In our continued efforts to improve the potential utility of the α-methylene-γ-lactone scaffold, 62 new and 59 known natural α-methylenelactam analogues including α-methylene-γ-lactams, α-arylidene-γ and δ-lactams, and 3-arylideneindolin-2-ones were synthesized as the bioisosteric analogues of the α-methylenelactone scaffold. The results of antifungal and cytotoxic activity indicated that among these derivatives compound (E)-1-(2, 6-dichlorobenzyl)-3-(2-fluorobenzylidene) pyrrolidin-2-one (Py51) possessed good selectivity with the highest antifungal activity against Colletotrichum orbiculare with IC50?=?10.4?μM but less cytotoxic activity with IC50?=?141.2?μM (against HepG2 cell line) and 161.2?μM (against human hepatic L02?cell line). Ultrastructural change studies performed by transmission electron microscope showed that Py51 could cause important cell morphological changes in C.?orbiculare, such as plasma membrane detached from cell wall, cell wall thickening, mitochondria disruption, a dramatic increase in vacuolation, and eventually a complete loss in the integrity of organelles. Significantly, mitochondria appeared one of the primary targets, as confirmed by their remarkably aberrant morphological changes. Analysis of structure–activity relationships revealed that incorporation of the aryl group into the α-exo-methylene and the N-benzyl substitution increased the activity. Meanwhile, the α-arylidene-γ-lactams have superiority in selectivity over the 3-arylideneindolin-2-ones. Based on the results, the N-benzyl substituted α-(2-fluorophenyl)-γ-lactam was identified as the most promising natural-based scaffold for further discovering and developing improved crop-protection agents.
- Delong, Wang,Lanying, Wang,Yongling, Wu,Shuang, Song,Juntao, Feng,Xing, Zhang
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p. 286 - 307
(2017/03/09)
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- SpinPhox/iridium(I)-catalyzed asymmetric hydrogenation of cyclic α-alkylidene carbonyl compounds
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Optically active medium-sized cyclic carbonyl compounds bearing an α-chiral carbon center are of interest in pharmaceutical sciences and asymmetric synthesis. Herein, SpinPhox/IrI catalysts have been demonstrated to be highly enantioselective in the asymmetric hydrogenation of the Ci£C bonds in the exocyclic α,β-unsaturated cyclic carbonyls, including a broad range of α-alkylidene lactams, unsaturated cyclic ketones, and lactones. It is noteworthy that the procedure can be successfully used in the asymmetric hydrogenation of the challenging α-alkylidenelactam substrates with six- or seven-membered rings, thus affording the corresponding optically active carbonyl compounds with an α-chiral carbon center in generally excellent enantiomeric excesses (up to 98 % ee). Synthetic utility of the protocol has also been demonstrated in the asymmetric synthesis of the anti-inflammatory drug loxoprofen and its analogue, as well as biologically important ε-aminocaproic acid derivatives. Take it for a spin: SpinPhox/IrI complexes are highly efficient and versatile in the enantioselective hydrogenation of a broad spectrum of exocyclic α,β-unsaturated carbonyl compounds, especially the challenging α-alkylidene lactam substrates with six- or seven-membered rings. The synthetic utility of the present protocol is demonstrated in the asymmetric synthesis of biologically important loxoprofen and ε-aminocaproic acid derivatives. Copyright
- Liu, Xu,Han, Zhaobin,Wang, Zheng,Ding, Kuiling
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p. 1978 - 1982
(2014/03/21)
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- HETEROCYCLIC ORGANIC COMPOUNDS
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The present application provides compounds of formula (I) that modulate the activity of stearoyl-CoA desaturase. Methods of using such derivatives to modulate the activity of stearoyl-CoA desaturase and pharmaceutical compositions comprising such derivatives are also encompassed.
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Page/Page column 48-49
(2008/06/13)
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