Development of nanostructured formulation from naringenin and silk fibroin and application for inhibition of lipoxygenase (LOX).

A simple low-energy method was used to obtain polymeric nanoparticles containing silk fibroin (SF), fatty butyl esters (oily phase) and the flavonoid naringenin. Experimental planning (Box-Behnken) was applied to investigate the optimal conditions for three factors (variation of the concentrations of SF, naringenin and fatty butyl ester) at three levels, with evaluation of particle size, polydispersity index (PDI) and zeta potential (ZP) as responses. The results showed that the polymeric particle was formed with sizes of 179.6 to 633.9 nm, PDI of 0.33 to 0.77 and ZP of -60.4 to -38.8 mV. The best responses under the optimized conditions (Nari-SF 9 and 15) were characterized through transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR), visible ultraviolet (UV-vis) and fluorescence, which confirmed that coated nanoparticles had been obtained. It was shown that the nanoformulation had excellent stability, the bioavailability of naringenin had been improved through use of the biopolymer and high inhibition of the enzyme lipoxygenase had been achieved in vitro.

Enantioselective ene-reduction of E-2-cyano-3-(furan-2-yl) acrylamide by marine and terrestrial fungi and absolute configuration of (R)-2-cyano-3-(furan-2-yl) propanamide determined by calculations of electronic circular dichroism (ECD) spectra.

This work reports the green organic chemistry synthesis of E-2-cyano-3(furan-2-yl) acrylamide under microwave radiation (55 W), as well as the use of filamentous marine and terrestrial-derived fungi, in the first ene-reduction of 2-cyano-3-(furan-2-yl) acrylamide to (R)-2-cyano-3-(furan-2-yl)propanamide. The fungal strains screened included Penicillium citrinum CBMAI 1186, Trichoderma sp. CBMAI 932 and Aspergillus sydowii CBMAI 935, and the filamentous terrestrial fungi Aspergillus sp. FPZSP 146 and Aspergillus sp. FPZSP 152. A compound with an uncommon CN-bearing stereogenic center at the α-C position was obtained by enantioselective reactions mediated in the presence of the microorganisms yielding the (R)-2-cyano-3-(furan-2-yl) propanamide 3a. Its isolated yield and e.e. ranged from 86% to 98% and 39% to 99%, respectively. The absolute configuration of the biotransformation products was determined by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. Finally, the tautomerization of 2-cyano-3-(furan-2-yl) propanamide 3a to form an achiral ketenimine was observed and investigated in presence of protic solvents.