Efficient One-Pot Synthesis of Bis(4-hydroxycoumarin)methanes in the Presence of Sulfonic Acid Functionalized Nanoporous Silica (SBA-Pr-SO3H)

Dicoumarol: from chemistry to antitumor benefits

Dicoumarol, a coumarin-like compound, is known for its anticoagulant properties associated with the ability to inhibit vitamin K, being prescribed as a drug for several decades. The pharmaceutical value of dicoumarol turned it into a focus of chemists' attention, aiming its synthesis and of dicoumarol derivatives, bringing to light new methodologies. In recent years, several other bioactive effects have been claimed for dicoumarol and its derivatives, including anti-inflammatory, antimicrobial, antifungal, and anticancer, although the mechanisms of action underlying them are mostly not disclosed and additional research is needed to unravel them. This review presents a state of the art on the chemistry of dicoumarols, and their potential anticancer characteristics, highlighting the mechanisms of action elucidated so far. In parallel, we draw attention to the lack of in vivo studies and clinical trials to assess the safety and efficacy as drugs for later application.

Dicoumarol derivatives: Green synthesis and molecular modelling studies of their anti-LOX activity

Dicoumarol derivatives were synthesized in the InCl3 catalyzed pseudo three-component reactions of 4-hydroxycoumarin with aromatic aldehydes in excellent yields. The reactions were performed in water under microwave irradiation. All synthesized compounds were characterized using NMR, IR, and UV-Vis spectroscopy, as well as with TD-DFT. Obtained dicoumarols were subjected to evaluation of their in vitro lipid peroxidation and soybean lipoxygenase inhibition activities. It was shown that five of ten examined compounds (3e, 3h, 3b, 3d, 3f) possess significant potential of antilipid peroxidation (84-97%), and that compounds 3b, 3e, 3h provided the highest soybean lipoxygenase (LOX-Ib) inhibition (IC50 = 52.5 µM) and 3i somewhat lower activity (IC50 = 55.5 µM). The bioactive conformations of the best LOX-Ib inhibitors were obtained by means of molecular docking and molecular dynamics. It was shown that, within the bioactive conformations interior to LOX-Ib active site, the most active compounds form the pyramidal structure made of two 4-hydroxycoumarin cores and a central phenyl substituent. This form serves as a spatial barrier which prevents LOX-Ib Fe2+/Fe3+ ion activity to generate the coordinative bond with the C13 hydroxyl group of the α-linoleate. It is worth pointing out that the most active compounds 3b, 3e, 3h and 3i can be candidates for further examination of their in vitro and in vivo anti-inflammatory activity and that molecular modeling study results provide possibility to screen bioactive conformations and elucidate the mechanism of dicoumarols anti-LOX activity.