66 research outputs found
Synthesis of Functionalized 3H-pyrrolo-[1,2,3-de] Quinoxalines via Gold-Catalyzed Intramolecular Hydroamination of Alkynes
A gold-catalyzed protocol to obtain functionalized 3H-pyrrolo [1,2,3-de] quinoxalines from suitable substituted N-alkynyl indoles has been proposed. The mild reaction conditions were revealed to be compatible with different functional groups, including halogen, alkoxyl, cyano, ketone, and ester, allowing the isolation of title compounds with yields from good to high. A reaction mechanism has been proposed, and theoretical calculations have been provided to rationalize the final step of the hypothesized reaction mechanism. As quinoxaline-containing polycyclic compounds, this class of molecules may represent a valuable template in medicinal chemistry and material science
Synthesis of 4-substituted-1,2-dihydroquinolines by means of gold-catalyzed intramolecular hydroarylation reaction of n-ethoxycarbonyl-n-propargylanilines
An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-Npropargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-metasubstituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning
Naturally-occurring alkaloids of plant origin as potential antimicrobials against antibiotic-resistant infections
Antibiotic resistance is now considered a worldwide problem that puts public health at risk. The onset of bacterial strains resistant to conventional antibiotics and the scarcity of new drugs have prompted scientific research to re-evaluate natural products as molecules with high biological and chemical potential. A class of natural compounds of significant importance is represented by alkaloids derived from higher plants. In this review, we have collected data obtained from various research groups on the antimicrobial activities of these alkaloids against conventional antibiotic-resistant strains. In addition, the structure-function relationship was described and commented on, highlighting the high potential of alkaloids as antimicrobials
Synthesis of indolo[1,2-c]quinazolines from 2-alkynylaniline derivatives through Pd-catalyzed indole formation/cyclization with N,N-dimethylformamide dimethyl acetal
An efficient strategy for the synthesis of 6-unsubstituted indolo[1,2-c]quinazolines is described. The Pd-catalyzed reaction of o-(oaminophenylethynyl) trifluoroacetanilides with Ar-B(OH)2 afforded 2-(o-aminophenyl)-3-arylindoles, that were converted to 12-arylindolo[1,2-c]quinazolines by adding dimethylformamide dimethyl acetal (DMFDMA) to the reaction mixture after extractive work-up. This reaction outcome is different from the previously reported Pd-catalyzed sequential reaction of the same substrates with Ar-I, Ar-Br and ArN2+BF4-, that afforded 12-arylindolo[1,2-c]quinazolin-6(5H)-ones. Moreover, 12-unsubstituted indolo[1,2-c]quinazolines can be obtained both by reacting 2-(o-aminophenyl)indoles with DMFDMA or by sequential Pd-catalyzed reaction of o-(o-aminophenylethynyl)aniline with DMFDMA
Valorization of By-Products from Biofuel Biorefineries: Extraction and Purification of Bioactive Molecules from Post-Fermentation Corn Oil
The aim of this work was to develop innovative and sustainable extraction, concentration,
and purification technologies aimed to recover target substances from corn oil, obtained as side stream
product of biomass refineries. Residues of bioactive compounds such as carotenoids, phytosterols,
tocopherols, and polyphenols could be extracted from this matrix and applied as ingredients for
food and feeds, nutraceuticals, pharmaceuticals, and cosmetic products. These molecules are well
known for their antioxidant and antiradical capacity, besides other specific biological activities,
generically involved in the prevention of chronic and degenerative diseases. The project involved the
development of methods for the selective extraction of these minor components, using as suitable
extraction technique solid phase extraction. All the extracted and purified fractions were evaluated
by NMR spectroscopic analyses and UV–Vis spectrophotometric techniques and characterized by
quali-quantitative HPLC analyses. TPC (total phenolic content) and TFC (total flavonoid content)
were also determined. DPPH and ABTS radical were used to evaluate radical quenching abilities.
Acetylcholinesterase (AChE), amylase, glucosidase, and tyrosinase were selected as enzymes in the
enzyme inhibitory assays. The obtained results showed the presence of a complex group of interesting
molecules with strong potential in market applications according to circular economy principles
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