- Usnic Acid Enaminone-Coupled 1,2,3-Triazoles as Antibacterial and Antitubercular Agents
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(+)-Usnic acid, a product of secondary metabolism in lichens, has displayed a broad range of biological properties such as antitumor, antimicrobial, antiviral, anti-inflammatory, and insecticidal activities. Interested by these pharmacological activities and to tap into its potential, we herein present the synthesis and biological evaluation of new usnic acid enaminone-conjugated 1,2,3-triazoles 10-44 as antimycobacterial agents. (+)-Usnic acid was condensed with propargyl amine to give usnic acid enaminone 8 with a terminal ethynyl moiety. It was further reacted with various azides A1-A35 under copper catalysis to give triazoles 10-44 in good yields. Among the synthesized compounds, saccharin derivative 36 proved to be the most active analogue, inhibiting Mycobacterium tuberculosis (Mtb) at an MIC value of 2.5 μM. Analogues 16 and 27, with 3,4-difluorophenacyl and 2-acylnaphthalene units, respectively, inhibited Mtb at MIC values of 5.4 and 5.3 μM, respectively. Among the tested Gram-positive and Gram-negative bacteria, the new derivatives were active on Bacillus subtilis, with compounds 18 [3-(trifluoromethyl)phenacyl] and 29 (N-acylmorpholinyl) showing inhibitory concentrations of 41 and 90.7 μM, respectively, while they were inactive on the other tested bacterial strains. Overall, the study presented here is useful for converting natural (+)-usnic acid into antitubercular and antibacterial agents via incorporation of enaminone and 1,2,3-triazole functionalities.
- Bangalore, Pavan K.,Vagolu, Siva K.,Bollikanda, Rakesh K.,Veeragoni, Dileep K.,Choudante, Pallavi C.,Misra, Sunil,Sriram, Dharmarajan,Sridhar, Balasubramanian,Kantevari, Srinivas
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supporting information
p. 26 - 35
(2020/01/03)
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- Design, synthesis and biological evaluation of new phthalimide and saccharin derivatives with alicyclic amines targeting cholinesterases, beta-secretase and amyloid beta aggregation
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The complexity of Alzheimer's disease (AD) calls for search of multifunctional compounds as potential candidates for effective therapy. A series of phthalimide and saccharin derivatives linked by different alicyclic fragments (piperazine, hexahydropyrimidine, 3-aminopyrrolidine or 3-aminopiperidine) with phenylalkyl moieties attached have been designed, synthesized, and evaluated as multifunctional anti-AD agents with cholinesterase, β-secretase and β-amyloid inhibitory activities. In?vitro studies showed that the majority of saccharin derivatives with piperazine moiety and one phthalimide derivative with 3-aminopiperidine fragment exhibited inhibitory potency toward acetylcholinesterase (AChE) with EeAChE IC50values ranging from 0.83?μM to 19.18?μM. The target compounds displayed inhibition of human β-secretase-1 (hBACE1) ranging from 26.71% to 61.42% at 50?μM concentration. Among these compounds, two multifunctional agents (26, [2-(2-(4-benzylpiperazin-1-yl)ethyl)benzo[d]isothiazol-3(2H)-one 1,1-dioxide] and 52, 2-(2-(3-(3,5-difluorobenzylamino)piperidin-1-yl)ethyl)isoindoline-1,3-dione) have been identified. Compound 26 exhibited the highest inhibitory potency against EeAChE (IC50?=?0.83?μM) and inhibitory activity against hBACE1 (33.61% at 50?μM). Compound 52 is a selective AChE inhibitor (IC50 AChE?=?6.47?μM) with BACE1 inhibitory activity (26.3% at 50?μM) and it displays the most significant Aβ anti-aggregating properties among all the obtained compounds (39% at 10?μM). Kinetic and molecular modeling studies indicate that 26 may act as non-competitive AChE inhibitor able to interact with both catalytic and peripheral active site of the enzyme.
- Panek, Dawid,Wi?ckowska, Anna,Wichur, Tomasz,Bajda, Marek,Godyń, Justyna,Jończyk, Jakub,Mika, Kamil,Janockova, Jana,Soukup, Ondrej,Knez, Damijan,Korabecny, Jan,Gobec, Stanislav,Malawska, Barbara
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p. 676 - 695
(2016/10/13)
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- Sulfonamide ligands attained through opening of saccharin derivatives
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Literature N-alkylsaccharins (saccharin-R2) have been shown in some cases to be O-alkylated regioisomers by crystallography (3 structures). The genuine former species react with (S)-H2NCHR1CH 2OH at 101°C in dio
- Robinson, Richard I.,Fryatt, Ross,Wilson, Claire,Woodward, Simon
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p. 4483 - 4489
(2007/10/03)
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- Retro-ene reactions. III. Alkylation of 4,5-dichloro-1-hydroxymethylpyridazin-6-ones: Synthesis of 4,5-dichloro-1-(ω-phthalimido and saccharin-2′-ylalkyl)pyridazin-6-ones
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4,5-Dichloro-1-(ω-phthalimido and saccharinyl-2′-ylalkyl)pyridazin-6-ones were synthesized from 4,5-dichloro-1-hydroxymethylpyridazin-6-one and the corresponding N-(ω-haloalkyl)phthalimides and saccharins via a fragmentation of retro-ene type.
- Kim, Sung-Kyu,Cho, Su-Dong,Moon, Jung-Kyen,Yoon, Yong-Jin
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p. 615 - 618
(2007/10/03)
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