It is well known that the carbamate done scaffold exhibits various biological effects and that the carbamate moiety (-NHCOO-) in the molecules is known to interact with a number of enzymes and biological structures [1, 2]. Carbamates are primarily known as local anaesthetics [3] and can also influence cardiovascular system functions [4, 5]. Nevertheless, N-benzoyl carbamate derivatives were also identified as potential antituberculotics [6�C17].Several authors have reported that tertiary amine local anesthetics decrease the value of the temperature of the gel-liquid crystalline phase transition Tm of model membranes, and this decrease correlated well with local anesthetic activity [18, 19]. A similar decrease of Tm was also observed in [2-(alkyloxy)-phenyl]-2-(l-piperidinyl)ethyl esters of carbamic acids [20].

The local anesthetic carbisocaine, a derivative of carbamic acid, was also found to exert a biphasic effect on the fluidity of egg yolk phosphatidylcholine (EYPC) model membranes as detected by the stearic acid spin probes with the paramagnetic doxyl group bound to C(5) or C(16). The fluidity initially increased with an increase in carbisocaine concentration, but at concentrations above 25mmol/L a decrease of fluidity has been observed [21]. The results of a study using heptacaine, the monohydrochloride of [2-(heptyloxy)phenyl]-2-(1-piperidinyl)ethyl ester of carbamic acid, showed that the fluidity of EYPC model membranes initially increased as the molar ratio of heptacaine:EYPC increased, but at heptacaine:EYPC molar ratios above 0.5, a decrease of fluidity was observed [22].

This decrease in fluidity may be due to interdigitation of hydrocarbon chains in the bilayer. Based on the results of a study on influence of2-piperidinoethyl-4-heptyloxyphenylcarbamate hydrochloride on metabolic function in Staphylococcus aureus, Mlynar?��k et al. suggested that the bacteriostasis could be equated with a loss of the cell’s ability to synthesize ATP, which, in turn, may stem from an uncoupling of oxidative phosphorylation [23]. Amphiphilic N,N-dimethylalkylamine N-oxides were found to modulate the activity of the purified sarcoplasmic reticulum (Ca-Mg)ATPase. The phase of insensitivity or slight stimulation of the activity at lower homologue concentrations was followed by the inhibition phase at higher concentrations [24].

As with other biological membranes under physiological conditions, the thylakoid membrane is almost impermeable to small charged molecules and ions. This property is essential for the maintenance of the electrochemical proton gradient generated by the photosynthetic electron transport chain, which serves as the driving GSK-3 force of ATP synthesis by ATP synthase. Consequently, alterations in membrane ion permeability are expected also to affect the efficiency of ATP production. Organic ammonium salts with local anaesthetic activity (e.g.