Antibacterial effect of 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1,4-naphthoquinone-4-imine on Staphylococcus aureus

NR SPERANDEO

EXPERIENTIA

Birkhjauser Verlag

Año: 1996 vol. 52 p. 600 - 600

0014-4754

he mechanism by which a new naphthoquinone derivative, the 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-l,4-naphthoquinone-4-imine (INQI-E) has antibacterial effect against Staphylococcus aureus was studied.The interaction of INQI-E with the bacteria was followed by absorption spectroscopy at 323 and 490 nm. Theabsorption band of INQI-E at 490 nm undergoes a hypochromic shift with a decrease of intensity. This effect wasfound to be reversible by oxygenation during the first hours of incubation. The participation of an oxidationreductionprocess related to the respiratory chain was demonstrated by oxygen consumption. An increase in 02uptake and inhibition of S. aureus growth was observed. Experiments with three inhibitors of the respiratory chaindemonstrated that the pathway induced by INQI-E was antimycin-resistant and KCN- and salicylhydroxamic acid(SHAM)-sensitive, which suggests that INQI-E is capable of diverting the normal electron flow to an alternatesuperoxide-producing route. On the