- Synthesis and SAR study of simple aryl oximes and nitrofuranyl derivatives with potent activity against Mycobacterium tuberculosis
-
Background: Oximes and nitrofuranyl derivatives are particularly important compounds in medicinal chemistry. Thus, many researchers have been reported to possess antibacterial, antiparasitic, insecticidal and fungicidal activities. Methods: In this work, we report the synthesis and the biological activity against Mycobacterium tuberculosis H37RV of a series of fifty aryl oximes, ArCH=N-OH, I, and eight nitrofuranyl compounds, 2-nitrofuranyl-X, II. Results: Among the oximes, I: Ar = 2-OH-4-OH, 42, and I: Ar = 5-nitrofuranyl, 46, possessed the best activity at 3.74 and 32.0 μM, respectively. Also, 46, the nitrofuran compounds, II; X = MeO, 55, and II: X = NHCH2Ph, 58, (14.6 and 12.6 μM, respectively), exhibited excellent biological activities and were non-cytotoxic. Conclusion: The compound 55 showed a selectivity index of 9.85. Further antibacterial tests were performed with compound 55 which was inactive against Enterococcus faecalis, Klebisiella pneumonae, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhymurium and Shigel-la flexneri. This study adds important information to the rational design of new lead anti-TB drugs. Structure-activity Relationship (SAR) is reported.
- Calixto, Stephane Lima,Carvalho, Guilherme da Silva Louren?o,Coimbra, Elaine Soares,Granato, Juliana da Trindade,Louren?o, Maria Cristina da Silva,Wardell, James,da Costa, Cristiane Fran?a,de Souza, Marcus Vinicius Nora
-
-
- Efficient symmetrical bidentate dioxime ligand-accelerated homogeneous palladium-catalyzed Suzuki-Miyaura coupling reactions of aryl chlorides
-
A series of N,O-bidentate ligands were synthesized using the Vilsmeier-Haack reaction and oximation. 2,5-Dihydroxyterephthalaldehyde dioxime (L8) as an efficient N,O-symmetrical bidentate ligand was prepared from hydroquinone. It was studied as a high activity ligand for palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids under mild conditions. The coupling reactions were performed in the presence of PdCl2 as the catalyst, L8 as the ligand, Na2CO3 as the base, PEG-400 as the PTC and in ethanol/water (1?:?1) as an environmentally benign solvent at 85 °C. Plentiful biaryls were obtained by the optimized reaction with good yields at a low palladium loading of 0.20 mol%.
- Song, Jinyi,Zhao, Hongyan,Liu, Yang,Han, Huatao,Li, Zhuofei,Chu, Wenyi,Sun, Zhizhong
-
p. 372 - 376
(2016/12/30)
-
- Synthesis and tyrosinase inhibitory activity of novel N-hydroxybenzyl-N-nitrosohydroxylamines
-
Several novel N-substituted N-nitrosohydroxylamines were synthesized. They all inhibited mushroom tyrosinase, but the type of inhibition was different depending on the substituent. Some N-(mono- or dihydroxybenzyl)-N-nitrosohydroxylamines exhibited uncompetitive inhibition with respect to L-dopa. Among them, compound 6 was also a competitive inhibitor with respect to oxygen. This observation suggests that another interaction by the meta- or para-hydroxyl group might stabilize the binding of the inhibitor to the enzyme through the oxygen binding site.
- Shiino, Mitsuhiro,Watanabe, Yumi,Umezawa, Kazuo
-
p. 129 - 135
(2007/10/03)
-
- [60]Fullerene Adducts with Improved Electron Acceptor Properties
-
The synthesis of C60-based dyads in which the C60 core is covalently attached to a strong electron acceptor moiety such as quinones, TCNQ or DCNQI derivatives, has been carried out by 1,3-dipolar cycloaddition of "in situ" generated azomethyne ylides or nitrile oxides to C60. As expected, the obtained pyrrolidino[3′,4′:1,2][60]fullerenes exhibit reduction potentials of the C60 framework which are cathodically shifted in comparison with the parent C60. In contrast, isoxazolo[4′,5′:1,2][60]-fullerenes show reduction waves for the fullerene core that are anodically shifted in comparison with the parent C60, which indicates that they are remarkably stronger acceptors than C60.The electron acceptor organic addend also undergoes an anodic shift due to the electronic interaction with the C60 moiety. The molecular geometry of pyrrolidinofullerenes has been calculated at the semiempirical PM3 level and reveals a highly distorted geometry for the acceptor moiety in compound 13, and a most stable conformation in which both dicyanomethylene units are far away from the C60 surface.
- Illescas, Beatriz M.,Martin, Nazario
-
p. 5986 - 5995
(2007/10/03)
-