Synthesis and biological activity of N-substituted-tetrahydro-γ-carbolines containing peptide residues

Amino acids and peptides as reactants in multicomponent reactions: modification of peptides with heterocycle backbones through combinatorial chemistry

In this study, amino acids and peptides were used as reactants in a Hantzsch multicomponent reaction in order to synthesize new structurally diverse molecules containing these synthons. As well, an applicable strategy for modification of these natural molecules with heterocycle backbones such as pyrimidine, xanthene and acridine is introduced. Using this method, a set of new amino acid- and peptide-functionalized heterocycles were synthesized in good to excellent yields under mild conditions. Furthermore, carbohydrates were used as substrates in the synthesis of some derivatives. Overall, this methodology allows the possibility of synthesis of large numbers of natural product-based libraries, using amino acids, peptides and carbohydrates through combinatorial chemistry.

Recent developments on synthesis and biological activities of γ-carboline

γ-Carboline alkaloids are a family of natural and synthetic agents that have diverse bioactivities including antiviral, antibacterial, antifungal, antiparasitic, antitumor, anti-inflammatory, neuropharmacological activities and so on. They constitute an important class of pharmacologically active scaffolds that exhibit biological activity via diverse mechanisms. This review provides an update on the recent developments (2010-2017) in the synthesis and biological activities of these compounds. In cases where sufficient information is available, the mechanism and the structure-activity relationship (SAR) of biological activity are presented, and based on our expertise in the field and careful analysis of the recent literature, for the potential of γ-carboline alkaloids as medicinal drugs is proposed.

Chiral Heteroditopic Baskets Designed from Triazolated Calixarenes and Short Peptides

Cone calix[4]arenes and calix[6]arenes bearing two, three, and four short peptide units each having two chiral carbon atoms were prepared. The syntheses were performed by using an efficient modular approach that includes the Ugi preparation of the azido-peptide followed by its reactions with the propargylated calixarenes under CuAAC (Cu(I) -catalyzed azide-alkyne cycloaddition) conditions. The three novel multitopic hosts were probed for their ability to bind metal ions by UV titration, and showed the highest complexation efficiency towards copper(II) and lead(II). These two cations possessed quite different complexation modes with copper(II) bound predominantly by multiple-triazole sites, in contrast to lead(II), which is stabilized mainly by multiple interactions with amide groups of the peptide units. Circular dichroism data for the free chiral hosts, their equimolar mixtures with copper(II) perchlorate and lead(II) perchlorate, and for tertiary mixtures of all three compounds showed the formation of mono- and binuclear complexes, or a switching behavior, depending on the structure of the host and the addition order of the cations.

One-pot synthesis of coumarin-3-carboxamides containing a triazole ring via an isocyanide-based six-component reaction

A facile, efficient, and environmentally friendly approach has been developed for the diversity oriented synthesis of trifunctional coumarin-amide-triazole containing compounds. A wide variety of pharmacologically significant and structurally interesting compounds were synthesized via a one-pot, six-component, tandem Knoevenagel/Ugi/click reaction sequence from readily available starting materials in ethanol at room temperature in excellent overall yields. Substituents could be independently varied at five different positions.