937-32-6Relevant articles and documents
Synthesis of 4-chalcogenyl pyrazoles via electrophilic chalcogenation/cyclization of α,β-alkynic hydrazones
Cheng, Yu-Fei,Gao, Wen-Chao,Niu, Yulan,Shang, Yu-Zhu,Tian, Jun,Yu, Xinzhang
, p. 1806 - 1811 (2020/03/17)
A facile method for the synthesis of 4-chalcogenylated pyrazoles has been developed via electrophilic chalcogenation/cyclization of α,β-alkynic hydrazones. The cyclization of α,β-alkynic aldehyde hydrazones could be induced by using either sulfenyl chloride or the S-electrophiles generated in situ from the reaction of NCS and arythiol. The developed method was successfully applied to the synthesis of the sulfenyl analogue of celecoxib.
Tryptophan trimers and tetramers inhibit dengue and Zika virus replication by interfering with viral attachment processes
Fikatas, Antonios,Meyen, Eef,Noppen, Sam,Pannecouque, Christophe,Schols, Dominique,Vervaeke, Peter,Camarasa, María-José,Martí-Marí, Olaia,Martínez-Guald, Belén,San-Félix, Ana
supporting information, (2020/02/29)
Here, we report a class of tryptophan trimers and tetramers that inhibit (at low micromolar range) dengue and Zika virus infection in vitro. These compounds (AL family) have three or four peripheral tryptophan moieties directly linked to a central scaffold through their amino groups; thus, their carboxylic acid groups are free and exposed to the periphery. Structure-activity relationship (SAR) studies demonstrated that the presence of extra phenyl rings with substituents other than COOH at the N1 or C2 position of the indole side chain is a requisite for the antiviral activity against both viruses. The molecules showed potent antiviral activity, with low cytotoxicity, when evaluated on different cell lines. Moreover, they were active against laboratory and clinical strains of all four serotypes of dengue virus as well as a selected group of Zika virus strains. Additional mechanistic studies performed with the two most potent compounds (AL439 and AL440) demonstrated an interaction with the viral envelope glycoprotein (domain III) of dengue 2 virus, preventing virus attachment to the host cell membrane. Since no antiviral agent is approved at the moment against these two flaviviruses, further pharmacokinetic studies with these molecules are needed for their development as future therapeutic/prophylactic drugs.
Reactivity of the nitrogen-centered tryptophanyl radical in the catalysis by the radical SAM enzyme NosL
Qianzhu, Haocheng,Ji, Wenjuan,Ji, Xinjian,Chu, Leixia,Guo, Chuchu,Lu, Wei,Ding, Wei,Gao, Jiangtao,Zhang, Qi
supporting information, p. 344 - 347 (2017/01/03)
The radical SAM tryptophan (Trp) lyase NosL involved in nosiheptide biosynthesis catalyzes two parallel reactions, converting l-Trp to 3-methyl-2-indolic acid (MIA) and to dehydroglycine and 3-methylindole, respectively. The two parallel reactions diverge from a nitrogen-centered tryptophanyl radical intermediate. Here we report an investigation on the intrinsic reactivity of the tryptophanyl radical using a chemical model study and DFT calculations. The kinetics of the formation and fragmentation of this nitrogen-centered radical in NosL catalysis were also studied in detail. Our analysis explains the intriguing catalytic promiscuity of NosL and highlights the remarkable role this enzyme plays in achieving an energetically highly unfavorable transformation.