Anti-inflammatory, ulcerogenic and platelet activation evaluation of novel 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids.

This study reports the synthesis of novel neolignans-celecoxib hybrids and the evaluation of their biological activity. Analogs8-13(L13-L18) exhibited anti-inflammatory activity, inhibited glycoprotein expression (P-selectin) related to platelet activation, and were considered non- ulcerogenic in the animal model, even with the administration of 10 times higher than the dose used in reference therapy. In silico drug-likeness showed that the analogs are compliant with Lipinski's rule of five. A molecular docking study showed that the hybrids8-13(L13-L18) fitted similarly with celecoxib in the COX-2 active site. According to this data, it is possible to infer that extra hydrophobic interactions and the hydrogen interactions with the triazole core may improve the selectivity towards the COX-2 active site. Furthermore, the molecular docking study with P-selectin showed the binding affinity of the analogs in the active site, performing important interactions with amino acid residues such as Tyr 48. Whereas the P-selectin is a promising target to the design of new anti-inflammatory drugs with antithrombotic properties, a distinct butterfly-like structure of 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids synthesized in this work may be a safer alternative to the traditional COX-2 inhibitors.

Antileishmanial Activity and Structure-Activity Relationship of Triazolic Compounds Derived from the Neolignans Grandisin, Veraguensin, and Machilin G.

Sixteen 1,4-diaryl-1,2,3-triazole compounds 4-19 derived from the tetrahydrofuran neolignans veraguensin 1, grandisin 2, and machilin G 3 were tested against Leishmania (Leishmania) amazonensis intracellular amastigotes. Triazole compounds 4-19 were synthetized via Click Chemistry strategy by 1,3-dipolar cycloaddition between terminal acetylenes and aryl azides containing methoxy and methylenedioxy groups as substituents. Our results suggest that most derivatives were active against intracellular amastigotes, with IC50 values ranging from 4.4 to 32.7 µM. The index of molecular hydrophobicity (ClogP) ranged from 2.8 to 3.4, reflecting a lipophilicity/hydrosolubility rate suitable for transport across membranes, which may have resulted in the potent antileishmanial activity observed. Regarding structure-activity relationship (SAR), compounds 14 and 19, containing a trimethoxy group, were the most active (IC50 values of 5.6 and 4.4 µM, respectively), with low cytotoxicity on mammalian cells (SI = 14.1 and 10.6). These compounds induced nitric oxide production by the host macrophage cells, which could be suggested as the mechanism involved in the intracellular killing of parasites. These results would be useful for the planning of new derivatives with higher antileishmanial activities.