Synthesis and evaluation of antitrypanosomal activity of some thiosemicarbazide derivatives of 1-butyl-6-fluoro-7-morpholino-4-oxo-1,4-dihydroquinoline-3-carboxylic acid

A Comprehensive Review on Chemical Synthesis and Chemotherapeutic Potential of 3-Heteroaryl Fluoroquinolone Hybrids

Fluoroquinolones have been studied for more than half a century. Since the 1960s, four generations of these synthetic antibiotics have been created and successfully introduced into clinical practice. However, they are still of interest for medicinal chemistry due to the wide possibilities for chemical modification, with subsequent useful changes in the pharmacokinetics and pharmacodynamics of the initial molecules. This review summarizes the chemical and pharmacological results of fluoroquinolones hybridization by introducing different heterocyclic moieties into position 3 of the core system. It analyses the synthetic procedures and approaches to the formation of heterocycles from the fluoroquinolone carboxyl group and reveals the most convenient ways for such procedures. Further, the results of biological activity investigations for the obtained hybrid pharmacophore systems are presented. The latter revealed numerous promising molecules that can be further studied to overcome the problem of resistance to antibiotics, to find novel anticancer agents and more.

Thiazolidine derivatives: In vitro toxicity assessment against promastigote and amastigote forms of Leishmania infantum and ultrastructural study

Neglected diseases, such as Leishmaniasis, constitute a group of communicable diseases that occur mainly in tropical countries. Considered a public health problem with limited treatment. Therefore, there is a need for new therapies. In this sense, our proposal was to evaluate in vitro two series of thiazolidine compounds (7a-7e and 8a-8e) against Leishmania infantum. We performed in vitro evaluations through macrophage cytotoxicity assays (J774) and nitric oxide production, activity against promastigotes and amastigotes, as well as ultrastructural analyzes in promastigotes. In the evaluation of cytotoxicity, the thiazolidine compounds presented CC₅₀ values between 8.52 and 126.83 μM. Regarding the evaluation against the promastigote forms, the IC₅₀ values ranged between 0.42 and 142.43 μM. Compound 7a was the most promising, as it had the lowest IC₅₀. The parasites treated with compound 7a showed several changes, such as cell body shrinkage, shortening and loss of the flagellum, intense mitochondrial edema and cytoplasmic vacuolization, leading the parasite to cell inviability. In assays against the amastigote forms, the compound showed a low IC₅₀ (0.65 μM). These results indicate that compound 7a was efficient for both evolutionary forms of the parasite. In silico studies suggest that the compound has good oral bioavailability. These results show that compound 7a is a potential drug candidate for the treatment of Leishmaniasis.