Analogues of Natural Chalcones as Efficient Inhibitors of AKR1C3

The Spectrum of Pharmacological Actions of Syringetin and Its Natural Derivatives-A Summary Review

Mono- and poly-O-methylated flavonols and their glycoside derivatives belong to the group of natural plant polyphenols with a wide spectrum of pharmacological activities. These compounds are known for their antioxidant, antimutagenic, hepatoprotective, antidiabetic, and antilipogenic properties. Additionally, they inhibit carcinogenesis and cancer development. Having in mind the multidirectional biological activity of methylated flavonols, we would like to support further study on their health-promoting activities; in this review we summarized the most recent reports on syringetin and some of its structural analogues: laricitrin, ayanin, and isorhamnetin. Natural sources and biological potential of these substances were described based on the latest research papers.

Two Important Anticancer Mechanisms of Natural and Synthetic Chalcones

ATP-binding cassette subfamily G and tubulin pharmacological mechanisms decrease the effectiveness of anticancer drugs by modulating drug absorption and by creating tubulin assembly through polymerization. A series of natural and synthetic chalcones have been reported to have very good anticancer activity, with a half-maximal inhibitory concentration lower than 1 µM. By modulation, it is observed in case of the first mechanism that methoxy substituents on the aromatic cycle of acetophenone residue and substitution of phenyl nucleus by a heterocycle and by methoxy or hydroxyl groups have a positive impact. To inhibit tubulin, compounds bind to colchicine binding site. Presence of methoxy groups, amino groups or heterocyclic substituents increase activity.

Hybrid Catalysts from Copper Biosorbing Bacterial Strains and Their Recycling for Catalytic Application in the Asymmetric Addition Reaction of B2(pin)2 on α,β-Unsaturated Chalcones

The recycling of heavy metal contaminants from wastewater as a source of valuable products perfectly fits with the principles of a Circular Economy system in view of restoring pollutants back into the system endowed with new social and economic benefits. Heavy metals are often present in such a low concentration that it makes the removal efficiency difficult to realize through the conventional physicochemical methods with high selectivity. Biosorption, conversely, by EPSs (extracellular polymeric substances) produced by several bacterial cells’ strains, is gaining a great deal of attention as an economic, efficient and sustainable depolluting process of wastewater from metal cations such as copper. Metal coordination to EPS components was thus deeply investigated by 1H NMR titration experiments. The 1,10–Phenanthroline–copper complex was exploited for quantifying the ability of different strains to sequester copper by a practical UV-Vis spectrophotometric method. The obtained data distinguished Serratia plymuthica strain SC5II as the bacterial strain displaying copper-adsorbing properties higher than any other, with Stenotrophomonas sp. strain 13a resulting in the worst one. Different analytical techniques, i.e., Dynamic Light Scattering (DLS), FT-IR analysis and SEM spectroscopy were thus employed to rationalize these results. Finally, the obtained copper chelates were successfully employed as hybrid catalysts in the asymmetric boron addition to α,β-unsaturated chalcones for the synthesis of valuable pharmaceutical intermediates, thus placing waste management in a new circular perspective.