Phomoxanthone A, Compound of Endophytic Fungi <i>Paecilomyces</i> sp. and Its Potential Antimicrobial and Antiparasitic

• Main Authors: Gisele da Costa Ramos (Author), João Victor Silva-Silva (Author), Luciano Almeida Watanabe (Author), José Edson de Sousa Siqueira (Author), Fernando Almeida-Souza (Author), Kátia S. Calabrese (Author), Andrey Moacir do Rosario Marinho (Author), Patrícia Santana Barbosa Marinho (Author), Aldo Sena de Oliveira (Author)
• Format: Book
• Published: MDPI AG, 2022-09-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

The present work reports the isolation and biological evaluation of three dimeric xanthones from <i>Paecilomyces</i> sp. EJC01.1 isolated as endophytic from <i>Schnella splendens</i>, a typical plant of the Amazon. The compounds phomoxanthone A (<b>1</b>), phomoxanthone B (<b>2</b>) and dicerandrol B (<b>3</b>) were isolated by chromatographic procedures and identified by spectroscopic methods of 1D and 2D NMR and MS. The extracts and compound <b>1</b> showed antimicrobial activities against <i>Bacillus subtilis</i>, <i>Escherichia coli</i>, <i>Staphylococcus aureus</i>, <i>Salmonella typhimurium</i> and <i>Pseudomonas aeruginosa</i>. The compound phomoxanthone A (<b>1</b>) showed greater inhibitory activity against <i>B. subtilis</i> (MIC of 7.81 µg mL⁻¹); in addition, it also pronounced inhibitory effect against promastigote forms of <i>Leishmania amazonensis</i> (IC₅₀ of 16.38 ± 1.079 µg mL⁻¹) and epimastigote forms <i>Trypanosoma cruzi</i> (IC₅₀ of 28.61 ± 1.071 µg mL⁻¹). To provide more information about the antibacterial activity of compound 1, an unprecedented molecular docking study was performed using S-ribosyl-homocysteine lyase (LuxS) (PDB ID 2FQO), which showed a possible interaction of phomoxanthone A with two of the residues (His58 and Cys126) that are fundamental for the catalysis mechanism in <i>B. subtilis</i>, which may be associated with the higher activity, when compared to other bacteria, observed in experimental studies. Additionally, quantum studies (DFT) were performed, for which a low gap value (5.982 eV) was observed, which corroborates the reactivity of phomoxanthone A. Thus, phomoxanthone A can be a good agent against pathogenic bacteria.

Item Description

10.3390/antibiotics11101332
2079-6382