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Alkannin is a plant-derived naphthoquinone that is isolated from the Boraginaceae family plants. In our previous studies, we found that shikonin, which is the R -enantiomer of alkannin, has potent antidiabetic activity by inhibiting the action of the aldose reductase (AR) enzyme and the protein-tyrosine phosphatase 1B (PTP1B). Therefore, in this study, we aim to explore the antidiabetic effect of alkannin targeting PTP1B and AR by employing in silico and in vitro techniques. For in silico , we used different parameters such as ADMET analysis, molecular docking, MD simulation, Root Mean Square Deviation (RMSD), protein-ligand mapping, and free binding energy calculation. The in vitro evaluation was done by assessing the inhibitory activity and enzyme kinetics of PTP1B and AR inhibition by alkannin. The in silico studies indicate that alkannin possesses favorable pharmacological properties and possesses strong binding affinity for diabetes target proteins. Hydrogen bonds (Val297, Ala299, Leu300, and Ser302) and hydrophobic interactions (Trp20, Val47, Tyr48, Trp79, Trp111, Phe122, Trp219, Val297, Cys298, Ala299, Leu300, and Leu301) are established by the compound, which potentially improves specificity and aids in the stabilization of the protein-ligand complex. The results from in vitro studies show a potent dose-dependent PTP1B inhibitory activity with an IC 50 value of 19.47 μM, and toward AR it was estimated at 22.77 μM. Thus, from the results it is concluded that a low IC 50 value of alkannin for both PTP1B and AR along with favorable pharmacological properties and optimal intra-molecular interactions indicates its utilization as a potential drug candidate for the management of diabetes and its end complications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Recently, researchers are seeking alternatives to replace Pt-based oxygen reduction reaction (ORR) catalysts used in fuel cells due to their high cost and certain stability and selectivity issues. For this purpose, we have synthesized a nanoconjugate, cobalt(II) porphyrin (5,10,15-triphenyl-20-(4-aminophenyl)porphyrinatocobalt(II), CoTPP-NH 2 ) covalently attached to the acid-functionalized multiwalled carbon nanotubes and characterized by various techniques including UV-vis spectroscopy, FTIR, TGA, FESEM, TEM, and Raman spectroscopy. The oxygen reduction performance of the nanoconjugate is checked in basic medium. The ORR onset potential of the nanoconjugate-modified electrode is nearly the same as that of the state-of-the-art platinum-carbon electrode and stable for more than 3000 CV cycles with a 20 mV difference in the onset potential before and after the 3000 CV cycles. The above extrapolations reveal that the nanoconjugate has efficient performance for the ORR in basic medium.