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Published on: May 31, 2024
An unusual reduction on the quinonoid ring of 5-amino-8-hydroxy-1,4-naphthoquinone by Staphylococcus aureus
L F C Medina1, V Stefani, A Brandelli
1Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciências dos Alimentos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Aims:
The objective of this study was to investigate the interactions between 5-amino-8-hydroxy-1,4-naphthoquinone (ANQ) and Staphylococcus aureus.
Methods And Results:
The compound ANQ display antimicrobial activity against S. aureus. During incubation with 50 microg ml(-1) of ANQ, an unusual reduction reaction takes place and leads to the isolation of 2,3-dihydro-5-amino-8-hydroxy-1,4-naphthoquinone (ANQ-H(2)), fully characterized by means of (13)C-NMR and (1)H-NMR, plus infrared, UV-visible and mass spectroscopy. Oxygen uptake by S. aureus cells was inhibited by ANQ, but in a significantly minor extent by ANQ-H(2).
Conclusions:
The ability of S. aureus to reduce the double bond at C2-C3 of the ANQ is a unusual behaviour for biological transformation of naphthoquinones.
Significance And Impact Of The Study:
This uncommon reaction may provide valuable understanding of the S. aureus regarding to the antimicrobial effect and the acquisition of resistance to naphthoquinones.
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