- Hydrazone derivatives enhance antileishmanial activity of thiochroman-4-ones
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Cutaneous leishmaniasis (CL) is a neglected tropical disease, which causes severe skin lesions. Due to the lack of effective vaccines, and toxicity or reduced effectiveness of available drugs in addition to complex and prolonged treatments, there is an urgent need to develop alternatives for the treatment for CL with different mechanisms of action. In our effort to search for new promising hits against Leishmania parasites we prepared 18 acyl hydrazone derivatives of thiochroman-4-ones. Compounds were evaluated for their in vitro antileishmanial activity against the intracellular amastigote form of Leishmania panamensis and cytotoxic activity against human monocytes (U-937 ATCC CRL-1593.2). Our results show that derivatization of the thiochroman-4-ones with acyl hydrazones significantly enhances the antileishmanial activity. Among the compounds tested semicarbazone and thiosemicarbazone derivatives of thioflavanone 19 and 20 displayed the highest antileishmanial activities, with EC50 values of 5.4 and 5.1 μM and low cytotoxicities (100.2 and 50.1 μM respectively), resulting in higher indexes of selectivity (IS).
- Vargas, Esteban,Echeverri, Fernando,Upegui, Yulieth A.,Robledo, Sara M.,Qui?ones, Wiston
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- Synthesis and evaluation of thiochroman-4-one derivatives as potential leishmanicidal agents
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The S-containing heterocyclic compounds benzothiopyrans or thiochromones stand out as having promising biological activities due to their structural relationship with chromones (benzopyrans), which are widely known as privileged scaffolds in medicinal chemistry. In this work, we report the synthesis of 35 thiochromone derivatives and the in vitro antileishmanial and cytotoxic activities. Compounds were tested against intracellular amastigotes of Leishmania panamensis and cytotoxic activity against human monocytes (U-937 ATCC CRL-1593.2). Compounds bearing a vinyl sulfone moiety, 4h, 4i, 4j, 4k, 4l and 4m, displayed the highest antileishmanial activity, with EC50 values lower than 10 μM and an index of selectivity over 100 for compounds 4j and 4l. When the double bond or the sulfone moiety was removed, the activity decreased. Our results show that thiochromones bearing a vinyl sulfone moiety are endowed with high antileishmanial activity and low cytotoxicity.
- Vargas, Esteban,Echeverri, Fernando,Vélez, Iván D.,Robledo, Sara M.,Qui?ones, Wiston
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- Visible-Light-Driven Iron-Promoted Thiocarboxylation of Styrenes and Acrylates with CO2
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The first thiocarboxylation of styrenes and acrylates with CO2 was realized by using visible light as a driving force and catalytic iron salts as promoters. A variety of important β-thioacids were obtained in high yields. This multicomponent reaction proceeds in an atom- and redox-economical manner with broad substrate scope under mild reaction conditions. Notably, high regio-, chemo-, and diasteroselectivity are observed. Mechanistic studies indicate that a radical pathway can account for the unusual regioselectivity.
- Ye, Jian-Heng,Miao, Meng,Huang, He,Yan, Si-Shun,Yin, Zhu-Bao,Zhou, Wen-Jun,Yu, Da-Gang
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supporting information
p. 15416 - 15420
(2017/11/01)
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- Fluoride ion-catalyzed conjugate addition for easy synthesis of 3-sulfanylpropionic acid from thiol and α,β-unsaturated carboxylic acid
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3-Sulfanylpropionic acids are obtained in excellent yields by proceeding through a simple, mild, and efficient procedure utilizing tetrabutylammonium fluoride (TBAF) as catalyst.
- Gao, Shijay,Tseng, Chi,Tsai, Cheng Hsuan,Yao, Ching-Fa
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p. 1955 - 1961
(2008/09/17)
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- Fluoroboric acid adsorbed on silica-gel (HBF4-SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds
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Fluoroboric acid adsorbed on silica-gel (HBF4-SiO2) has been found to be a new and highly efficient heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of
- Sharma, Gaurav,Kumar, Raj,Chakraborti, Asit K.
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p. 4272 - 4275
(2008/09/21)
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- Natural phosphate modified with lithium nitrate: A new efficient catalyst for the construction of carbon-carbon, carbon-sulfur, and carbon-nitrogen bonds
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The addition of small amounts of lithium nitrate to natural phosphate followed by calcination gives a new catalyst Li/NP (weight ratio LiNO3/NP = 1/15). This material showed catalytic activity in the Michael addition of amines, mercaptans, and active methylene compounds to chalcone derivatives with high yields under mild reaction conditions. Li/NP is used as the catalyst for a facile synthesis of -amino acids, -sulfur acids, and 4 H-chromenes under heterogeneous conditions. The usual, undesirable byproducts from the Michael condensation such as 1,2-addition, bis-addition, and polymerization compounds are not observed with this method. The work-up procedure is simplified by simple filtration with the use of Li/NP.
- Zahouily, Mohamed,Mounir, Bahija,Cherki, Hind,Bahlaouan, Bouchaib,Rayadh, Ahmed,Sebti, Said
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p. 1203 - 1217
(2008/02/02)
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- Iodine catalyzed conjugate addition of mercaptans to α,β- unsaturated carboxylic acids under solvent-free condition
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We have described herein molecular iodine catalyzed Michael addition of thiol to α,β-unsaturated carboxylic acids. This environmentally benign catalytic system (iodine) used under mild and solvent-free conditions to achieve the corresponding adducts in excellent yield.
- Gao, Shijay,Tzeng, Tingkai,Sastry,Chu, Cheng-Ming,Liu, Ju-Tsung,Lin, Chunchi,Yao, Ching-Fa
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p. 1889 - 1893
(2007/10/03)
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- Nickel chloride hexahydrate: A novel reagent for Michael addition on α,β-unsaturated acids - A facile one-step route to 3-arylmercaptopropionic acids from thiophenols and α,β-unsaturated acids
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Michael additions have been successfully carried out in presence of a base, but when an α,β00-unsaturated acid is a substrate, it would be most unlikely for a carboxylate ion bearing α,β-unsaturated site to undergo a Michael addition. This problem has been circumvented in the present paper by carrying out a nickel chloride hexahydrate mediated Michael addition of thiophenols 1a-k on acrylic acid and on cinnamic acid to give 3-aryl mercaptopropionic acids 3a-k in excellent yield.
- Gogia, Santosh,Sirohi, Reenu,Gupta, Suman,Kishore,Joshi
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p. 1008 - 1011
(2007/10/03)
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- Hydroxamic acid derivatives as potent peptide deformylase inhibitors and antibacterial agents
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Low-molecular-weight β-sulfonyl- and β-sulfinylhydroxamic acid derivatives have been synthesized and found to be potent inhibitors of Escherichia coli peptide deformylase (PDF). Most of the compounds synthesized and tested displayed antibacterial activities that cover several pathogens found in respiratory tract infections, including Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The potential of these compounds as antibacterial agents is discussed with respect to selectivity, intracellular concentrations in bacteria, and potential for resistance development.
- Apfel, Christian,Banner, David W.,Bur, Daniel,Dietz, Michel,Hirata, Takahiro,Hubschwerlen, Christian,Locher, Hans,Page, Malcolm G. P.,Pirson, Wolfgang,Rossé, Gérard,Specklin, Jean-Luc
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p. 2324 - 2331
(2007/10/03)
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- Chemotherapeutic agents
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A method of treating or preventing viral infections, in particular rhinovirus infections comprising the administration of an effective amount of a 2-phenyltetralin derivative or a heterocyclic analogue thereof. Pharmaceutical compositions containing these compounds, and some novel compounds are also disclosed.
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- Substitution Reactions of Thallous Thiophenoxide and Thallous Phenylselenide with Halogen-Bearing Substrates
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Thallous thiophenoxide (1) and thallous selenide (2) were prepared by the action of either thallous ethoxide or thallous pentoxide on thiophenol and benzeneselenol.The reagents 1 and 2 reacted readily with aroyl and acyl halides, imidoyl chlorides, α-halo ketones, α-halo esters, α-halo lactones, α-halo carboxylic acids, allyl halides, alkyl halides, chlorotrimethylsilane, chloroacetonitrile, and N-chlorosuccinimide to give substitution products and varying amounts of diphenyl disulfide and diphenyl diselenide.The reactions were run as heterogeneous mixtures in ether.The origin of the diphenyl disulfide and diphenyl diselenide was homolytic cleavage of the thallium-sulfur or thallium-selenium bond, on the basis of the products derived from the reactions of N-chlorosuccinimide with 1 and 2.
- Detty, Michael R.,Wood, Gary P.
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