Synthesis, and Biological Evaluation of New 1,3,4‐Thiadiazolium‐2‐phenylamine Derivatives Against Leishmania amazonensis Promastigotes and Amastigotes.

Abstract

Derivatives Against Leishmania amazonensis Promastigotes and Amastigotes. -14 1,3,4-Thiadiazolium-2-phenylamine derivatives, among them 4 new compounds, e.g. (IIIa) and (IIIb), are prepared and tested against promastigote and amastigote forms of Leishmania amazonensis. -(DA SILVA, E. F.; CANTO-CAVALHEIRO, M. M.; BRAZ, V. R.; CYSNE-FINKELSTEIN, L.; LEON, L. L.; ECHEVARRIA*, A.; Eur.

Synthesis and antileishmanial activity of 5-(5-nitroaryl)-2-substituted-thio-1,3,4-thiadiazoles

“…On the other hand, the anti-parasitic property of 1,3,4-thiadiazoles has been well documented and their attachment to other heterocycles often alters the bioactivity, depending upon the type of substituent and the position of the attachment [17,18]. Accordingly, in continuation of our previous papers [10,19] which were mostly devoted to the synthesis of diverse heterocycles with the emphasis on the role of 2,5-disubstituted-1,3,4-thiadiazole derivatives as anti-parasitic drugs, we decided to focus our attention toward the synthesis of new structures of 5-(5-nitroaryl)-2-substitutedthio-1,3,4-thiadiazoles to evaluate their antileishmanial activity against the promastigote form of Leishmania major.…”

Preparations of diversely substituted thiosemicarbazides and N-hydroxythioureas

“…1 Biologically active thiosemicarbazide derivatives include 1,3,4-thiadiazoles, as antibacterial 2 and antifungal 3 agents, and 1,3,4-thiadiazolium-2-amidines as anticonvulsant, 4 antimicrobial, 5 and antitumor agents. …”

Antileishmanial Activity of 1,3,4-Thiadiazolium-2-Aminide in Mice Infected withLeishmania amazonensis

“…1) inhibit the in vitro growth of Leishmania amazonensis, L. brasiliensis, and L. chagasi promastigotes (6,21). The chemistry of mesoionic rings, especially their use as masked dipoles, has been a fruitful area of research since the late 1950s.…”

“…1), the compounds with the best in vitro activity were selected as promising drug candidates (6). Of the two compounds selected, the mesoionic with a 4-OCH 3 substituent was more effective than the one with no substitution (MI-H-H).…”

“…However, mesoionic derivatives should be tested orally in future research. These compounds are able to interact with biomolecules; although the compounds are internally charged, they are neutral overall and therefore can cross biological membranes in vivo (6). These properties could allow other routes of treatment with mesoionic derivatives, meaning advantages over antimonials.…”