Design and Synthesis of New Anthranyl Phenylhydrazides: Antileishmanial Activity and Structure-Activity Relationship.

Leishmaniasis is a neglected tropical disease affecting millions of people worldwide. A centenary approach to antimonial-based drugs was first initiated with the synthesis of urea stibamine by Upendranath Brahmachari in 1922. The need for new drug development led to resistance toward antimoniates. New drug development to treat leishmaniasis is urgently needed. In this way, searching for new substances with antileishmanial activity, we synthesized ten anthranyl phenylhydrazide and three quinazolinone derivatives and evaluated them against promastigotes and the intracellular amastigotes of Leishmania amazonensis. Three compounds showed good activity against promastigotes 1b, 1d, and 1g, with IC50 between 1 and 5 µM. These new phenylhydrazides were tested against Leishmania arginase, but they all failed to inhibit this parasite enzyme, as we have shown in a previous study. To explain the possible mechanism of action, we proposed the enzyme PTR1 as a new target for these compounds based on in silico analysis. In conclusion, the new anthranyl hydrazide derivatives can be a promising scaffold for developing new substances against the protozoa parasite.

New hydrazides derivatives of isoniazid against Mycobacterium tuberculosis: Higher potency and lower hepatocytotoxicity.

Tuberculosis (TB) is one of the leading causes of death worldwide. The emergence of multi-drug resistant strains of Mycobacterium tuberculosis (Mtb) and TB-HIV co-infection are major public health challenges. The anti-TB drugs of first choice were developed more than 4 decades ago and present several adverse effects, making the treatment of TB even more complicated and the development of new chemotherapeutics for this disease imperative. In this work, we synthesized two series of new acylhydrazides and evaluated their activity against different strains of Mtb. Derivatives of isoniazid (INH) showed important anti-Mtb activity, some being more potent than all anti-TB drugs of first choice. Moreover, three compounds proved to be more potent than INH against resistant Mtb. The Ames test showed favorable results for two of these substances compared to INH, one of which presented expressly lower toxicity to HepG2 cells than that of INH. This result shows that this compound has the potential to overcome one of the main adverse effects of this drug.