Chemical Synthesis of Selenium-containing Peptides.

Selenium (Se), a semi-metallic element, has chemical properties similar to sulfur; however, it has comparatively low electronegativity as well as a large atomic radius than sulfur. These features bestow selenium-containing compounds with extraordinary reactivity, sensitivity, and potential for several applications like chemical alteration, protein engineering, chemical (semi)synthesis, etc. Organoselenium chemistry is emerging fastly, however, examples of effective incorporation of Se into the peptides are relatively scarce. Providentially, there has been a drastic interest in synthesizing and applying selenoproteins and selenium-containing peptides over the last few decades. In this minireview, the synthetic methodologies of selenium-containing peptides and a brief description of their chemistry and biological activities are summarized. These methodologies enable access to various natural and unnatural selenium-containing peptides that have been used in a range of applications, from modulating protein characteristics to structure-activity relationship (SAR) studies for applications in nutraceuticals and drug development. This review aims at the audience interested in learning about the synthesis as well as will open new dimensions for their future research by aiding in the design of biologically interesting selenium-containing peptides.

(Benzylideneamino)triazole-Thione Derivatives of Flurbiprofen: An Efficient Microwave-Assisted Synthesis and In Vivo Analgesic Potential.

Triazole is an imperative heterocycle renowned for its broad-spectrum biological significance. In this manuscript, facile microwave-assisted synthesis of a series of 4-(benzylideneamino)-3-(1-(2-fluoro-[1,1'-biphenyl]-4-yl)ethyl)-1H-1,2,4-triazole-5(4H)-thione 6(a-m) derivatives along with their in vivo analgesic activity is reported. 2-(2-Fluoro-[1,1'-biphenyl]-4-yl)propanoic acid (flurbiprofen) was converted to methyl 2-(2-fluoro-[1,1'-biphenyl]-4-yl)propanoate using microwave irradiation, followed by its hydrazinolysis with hydrazine monohydrate. 2-(2-Fluoro-[1,1'-biphenyl]-4-yl)propanehydrazide thus obtained was converted to 4-amino-3-(1-(2-fluoro-[1,1'-biphenyl]-4-yl)ethyl)-1H-1,2,4-triazole-5(4H)-thione, followed by its condensation with different aromatic aldehydes to get the title compounds. Structures of all the synthesized compounds were established using different methods (1H NMR and 13C NMR spectroscopies, mass spectrometry, and elemental analysis) and evaluated for their potential as analgesic agents by tail flick, hot plate, and writhing methods. The results of this in vivo study revealed several compounds as potent analgesic agents among which compound 6e showed significant analgesic effect for all the three assays employed.

Design, synthesis, crystal structure, in vitro cytotoxicity evaluation, density functional theory calculations and docking studies of 2-(benzamido) benzohydrazide derivatives as potent AChE and BChE inhibitors.

A series of hydrazone derivatives of 2-(benzamido) benzohydrazide was designed, synthesized, and characterized utilizing FTIR, NMR and UV spectroscopic techniques along with mass spectrometry. Compound 10 was also characterized through X-ray crystallography. These synthesized compounds were assessed for their potential as anti-Alzheimer's agents by checking their AChE and BChE inhibition properties by in vitro analysis. The synthesized derivatives were also evaluated for their antioxidant potential along with cytotoxicity studies. The results clearly indicated that dual inhibition of both the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was achieved by most of the compounds (03-13), showing varying IC50values. Remarkably, compound 06 (IC50 = 0.09 ± 0.05 for AChE and 0.14 ± 0.05 for BChE) and compound 13 (IC50 = 0.11 ± 0.03 for AChE and 0.10 ± 0.06 for BChE) from the series showed IC50 values comparable to the standard donepezil (IC50 = 0.10 ± 0.02 for AChE and 0.14 ± 0.03 for BChE). Moreover, the derivative 11 also exhibited selective inhibition against BChE with IC50 = 0.12 ± 0.09. Meanwhile, compounds 04 and 10 exhibited good anti-oxidant activities, showing % scavenging of 95.06% and 82.55%, respectively. Cytotoxicity studies showed that the synthesized compounds showed cell viability greater than 80%; thus, these compounds can be safely used as drugs. DFT and molecular docking studies also supported the experimental findings.

Synthesis of new S-substituted derivatives of 5-[3-(1H-indol-3-yl)propyl]-1,3,4-oxadiazol-2-ylhydrosulfide as suitable antibacterial and anticancer agents with moderate cytotoxicity.

In the study presented here, the nucleophilic substitution reaction of 5-[3-(1H-indol-3-yl)propyl]-1,3,4-oxadiazol-2-ylhydrosulfide was carried out with different alkyl/aralkyl halides (5a-r) to form its different S-substituted derivatives (6a-r), as depicted in scheme 1. The structural confirmation of all the synthesized compounds was done by IR, 1H-NMR, 13C-NMR and CHN analysis data. Bacterial biofilm inhibitory activity of all the synthesized compounds was carried out against Bacillus subtilis and Escherichia coli. The anticancer activity of these molecules was ascertained using anti-proliferation (SRB) assay on HCT 116 Colon Cancer Cell lines while the cytotoxicity of these molecules was profiled for their haemolytic potential. From this investigation it was rational that most of the compounds exhibited suitable antibacterial and anticancer potential along with a temperate cytotoxicity.