Semi-synthesis, α-amylase inhibition, and kinetic and molecular docking studies of arylidene-based sesquiterpene coumarins isolated from Ferula tunetana Pomel ex Batt.

Despite all the significant progresses made to enhance the efficacy of the existing bank of drugs used to manage and cure type II diabetes mellitus, there is still a need to search and develop novel bioactive compounds with superior efficacy and minimal adverse effects. This study describes the valorization of the natural bioactive sesquiterpene coumarin via the semi-synthesis of new analogs and the study of their α-amylase inhibition activity. The sesquiterpene coumarin named coladonin (1) was quantitatively isolated from the chloroform extract of endemic Ferula tunetana roots. Subsequently, the oxidation of 1via the Jones oxidation reaction, used as a key reaction, afforded precursor 2. The condensation of oxidized coladonin (2) with various aryl aldehydes provided a series of new arylidene-based sesquiterpene coumarin derivatives (3a-m), which were characterized by NMR and ESI-HRMS experiments. All derivatives evaluated in vitro for their α-amylase inhibitory potential showed interesting α-amylase inhibition with IC50 values ranging from 7.24 to 28.98 µM. Notably, compounds 3k and 3m exhibited lower IC50 values (7.24 µM and 8.38 µM, respectively) compared to the standard (acarbose: IC50 = 9.83 µM). In addition, the structure-activity relationship (SAR) for all the compounds was studied. The most active compounds were found to be mixed-type inhibitors, which was revealed by kinetic studies. Furthermore, molecular in silico docking studies were established for all synthesized analogs with the binding site for the α-amylase enzyme.

A novel EIS field effect structures coated with TESUD-PPy-PVC-dibromoaza[7]helicene matrix for potassium ions detection.

In this work, we describe the development of new Aza[7]helicene-containing PVC-based membranes for the K(+) ions quantification. Here, silicon nitride-based structures (Si-p/SiO2/Si3N4) were developed and the surface was activated, functionalized with an aldehyde-silane (11-(Triethoxysilyl)undecanal (TESUD)), functionalized with polypyrrole (PPy), and coated with the polyvinylchloride (PVC)-membrane containing the Aza[7]helicene as ionophore. All stages of functionalization process have been thoroughly studied by contact angle measurements (CAMs) and atomic force microscopy (AFM). The developed ion-selective electrode (ISE) was then applied using electrochemical impedance spectroscopy (EIS) for the detection of potassium ions. A linear range was observed between 1.0 × 10(-8) M to 1.0 × 10(-3) M and a detection limit of 1.0 × 10(-8) M was observed. The EIS results have showed a good sensitivity to potassium ion using this novel technique. The target helicene exhibited good solubility and excellent thermal stability with a high decomposition temperature (Td > 300 °C) and it indicates that helicene may be a promising material as ionophore for ion-selective electrodes (ISEs) elaboration.