Spectroscopic (FT-IR, FT-Raman) investigations, quantum chemical calculations, ADMET and molecular docking studies of phloretin with B-RAF inhibitor

Functionalization of Polyhydroxyalkanoates (PHA)-Based Bioplastic with Phloretin for Active Food Packaging: Characterization of Its Mechanical, Antioxidant, and Antimicrobial Activities

The formulation of eco-friendly biodegradable packaging has received great attention during the last decades as an alternative to traditional widespread petroleum-based food packaging. With this aim, we designed and tested the properties of polyhydroxyalkanoates (PHA)-based bioplastics functionalized with phloretin as far as antioxidant, antimicrobial, and morpho-mechanic features are concerned. Mechanical and hydrophilicity features investigations revealed a mild influence of phloretin on the novel materials as a function of the concentration utilized (5, 7.5, 10, and 20 mg) with variation in FTIR e RAMAN spectra as well as in mechanical properties. Functionalization of PHA-based polymers resulted in the acquisition of the antioxidant activity (in a dose-dependent manner) tested by DPPH, TEAC, FRAR, and chelating assays, and in a decrease in the growth of food-borne pathogens (Listeria monocytogenes ATCC 13932). Finally, apple samples were packed in the functionalized PHA films for 24, 48, and 72 h, observing remarkable effects on the stabilization of apple samples. The results open the possibility to utilize phloretin as a functionalizing agent for bioplastic formulation, especially in relation to food packaging.

Dual Antimelanogenic Effect of Nicotinamide-Stabilized Phloretin Nanocrystals in Larval Zebrafish

Melanin is a kind of dark insoluble pigment that can cause pigmentation and free-radical clearance, inducing melasma, freckles, and chloasma, affecting the quality of life of patients. Due to poor water solubility and low safety, the absorption of poorly water-soluble drugs is limited by the hinderance of a skin barrier. Therefore, it is necessary to develop new, safe, and highly efficient drugs to improve their transdermal absorption efficiency and thus to inhibit the production of melanin. To address these issues, we developed a new nicotinamide (NIC)-stabilized phloretin nanocrystals (PHL-NCs). First, NC technology significantly increased the solubility of PHL. The in vitro release results indicated that at 6 h, the dissolution of the PHL-NIC-NCs was 101.39% ± 2.40% and of the PHL-NCs was 84.92% ± 4.30%, while that of the physical mixture of the two drugs was only 64.43% ± 0.02%. Second, NIC acted not only as a stabilizer to enlarge the storage time of PHL-NIC-NCs (improved to 10-day in vitro stability) but also as a melanin transfer inhibitor to inhibit melanin production. Finally, we verified the melanin inhibition effect of PHL-NIC-NCs evaluated by the zebrafish model. It showed that 0.38 mM/L PHL-NIC-NCs have a lower tyrosinase activity at 62.97% ± 0.52% and have less melanin at 36.57% ± 0.44%. The inhibition effect of PHL-NCs and PHL-NIC-NCs was stronger compared to the positive control arbutin. In conclusion, the combination of NIC and PHL achieves better inhibition of tyrosinase and inhibition of melanin production through synergism. This will provide a direction to the subsequent development of melanin-inhibiting drugs and the combined use of pharmaceutical agents.

Donor functionalized perylene and different π-spacer based sensitizers for dye-sensitized solar cell applications - a theoretical approach

A series of perylene-based novel metal-free organic dye sensitizers are designed and optimized for dye-sensitized solar cell (DSSC) applications. The electronic and optical properties are analyzed through density functional theory (DFT) and time-dependent density functional theory (TD-DFT) approach. For perylene-based donors, the effects of additional donor units and different π-spacer positions were investigated. Cyanovinyl and thiophene are used as π-spacers, dimethylamine (DM) and N-N-dimethylaniline (DMA) are used as additional donors, and cyanoacrylic acid is used as mono acceptor unit for the designed sensitizers. Natural bonding orbitals (NBOs), frontier molecular orbitals (FMO), UV-Vis, and nonlinear orbital analysis were predicted to find the net electron transfer, energy gap, absorption spectra, and electronic charge distribution for perylene-based dye sensitizers, respectively. The electron injection and electron regeneration properties were also analyzed for perylene-based sensitizers.

Corrosion Inhibition of Mild Steel in Hydrochloric Acid Environments Containing Sonneratia caseolaris Leaf Extract

Sonneratia caseolaris leaf extract was characterized for its mitigation of the electrochemical corrosion of steel in naturally aerated hydrochloric acid environments by electrochemical methods and surface analysis. The presence of S. caseolaris leaf extract (SCLE) in the hydrochloric acid medium ameliorated the corrosion resistance of steel via the adsorption of SCLE species to form a barrier layer. The improved inhibition effectiveness was demonstrated to be independent of the SCLE concentration and the corrosive environment. The highest inhibition performance of approximately 98% was reached for steel in a 1 M HCl medium containing 2500 ppm SCLE. The performance significantly decreased with a decrease in the HCl concentration from 1.00 to 0.01 M with the same SCLE concentration. In addition, severe corrosion occurred on the uninhibited steel surface but was significantly reduced on the inhibited steel surface. The analyzed results also indicated the existence of electronegative functional groups in SCLE, which could promote the adsorption process for the self-formation of the barrier layer on the steel surface. The work reported herein suggested a powerful strategy to mitigate electrochemical corrosion by adding an effective new inhibitor to achieve a green inhibitor system.