Optimization of 1,4-Naphthoquinone Hit Compound: A Computational, Phenotypic, and In Vivo Screening against <i>Trypanosoma cruzi</i>

• Main Authors: Leonardo S. Lara, Guilherme C. Lechuga, Caroline dos S. Moreira, Thaís B. Santos, Vitor F. Ferreira, David R. da Rocha, Mirian C. S. Pereira
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Molecules
• Subjects: <i>Trypanosoma cruzi</i>; naphthoquinones; trypanocidal activity; chemotherapy; compound optimization
• Online Access: https://www.mdpi.com/1420-3049/26/2/423

Chagas disease (CD) still represents a serious public health problem in Latin America, even after more than 100 years of its discovery. Clinical treatments (nifurtimox and benznidazole) are considered inadequate, especially because of undesirable side effects and low efficacy in the chronic stages of the disease, highlighting the urgency for discovering new effective and safe drugs. A small library of compounds (<b>1a</b>–<b>i</b> and <b>2a</b>–<b>j</b>) was designed based on the structural optimization of a Hit compound derived from 1,4-naphthoquinones (C2) previously identified. The biological activity, structure-activity relationship (SAR), and the in silico physicochemical profiles of the naphthoquinone derivatives were analyzed. Most modifications resulted in increased trypanocidal activity but some substitutions also increased toxicity. The data reinforce the importance of the chlorine atom in the thiophenol benzene ring for trypanocidal activity, highlighting <b>1g,</b> which exhibit a drug-likeness profile, as a promising compound against <i>Trypanosoma cruzi</i>. SAR analysis also revealed <b>1g</b> as cliff generator in the structure-activity similarity map (SAS maps). However, compounds C2 and <b>1g</b> were unable to reduce parasite load, and did not prevent mouse mortality in <i>T. cruzi</i> acute infection. Phenotypic screening and computational analysis have provided relevant information to advance the optimization and design of new 1,4-naphthoquinone derivatives with a better pharmacological profile.