- Alkylated histidine based short cationic antifungal peptides: Synthesis, biological evaluation and mechanistic investigations
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Current clinically used antifungal agents suffer from several drawbacks that have urgently necessitated the development of new antifungal agents with unusual mechanisms of action. In this context, antifungal peptides (AFPs) open up new perspectives in drug design by providing an entire range of highly selective and nontoxic pharmaceuticals. Here, we report the development of novel short AFPs with the synthesis of two series of tripeptide based compounds named as His(2-alkyl)-Arg-Lys (series I) and His(2-alkyl)-Arg-Arg (series II). The series II peptides were found to be selectively active against Cryptococcus neoformans whereas some peptides displayed encouraging activities against other fungal strains such as Candida albicans, Candida kyfer, Aspergillus Niger and Neurospora crassa. The cytotoxic experiments were performed on active compounds using Hek-293 and HeLa cells which exhibited negligible cytotoxic effect up to the highest test concentration. Further, the most potent peptide was subjected to mechanistic studies using TEM analysis. Two sets of SUVs mimicking microbial membrane and mammalian membrane were treated with the most potent peptide. The results of this study were found to be perfectly in corroboration with the antifungal activity in relation to the differences between microbial and mammalian cell membrane composition, thereby, indicating that the reported peptides may also be less susceptible to the common mechanisms of drug resistance.
- Mittal, Sherry,Kaur, Sarabjit,Swami, Anuradha,Maurya, Indresh K.,Jain, Rahul,Wangoo, Nishima,Sharma, Rohit K.
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p. 41951 - 41961
(2016/05/19)
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- Synthesis of L-histidine specifically labelled with stable isotopes
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(2'-13C)-, (1'-15N)- and (3'-15N)-L-Histidine were prepared according to a synthetic scheme that allows the 13C or 15N labelling of all carbon and nitrogen positions or any combination of positions.A 1,5-disubstituted imidazole ring was constructed via condensation of tosylmethyl isocyanide with 3-phenylpropenal and subsequent cycloaddition of benzylamine.The imidazole intermediate was converted into 1-benzyl-5-(chloromethyl)-imidazolium chloride which was coupled to a glycine moiety via an enantioselective coupling with the bislactim ether of cyclo-D-valylglycine.Deprotection of the coupling product afforded L-histidine in high optical purity.Syntheses for the isotopically labelled synthons were developed starting from simple, comercially available, highly enriched compounds.The labelled L-histidines were characterized by mass spectrometry and 1H-, 13C- and 15N-NMR spectroscopy.
- Cappon, J. J.,Witters, K. D.,Baart, J.,Verdegem, P. J. E.,Hoek, A. C.,et al.
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p. 318 - 328
(2007/10/02)
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