Quaternary ammoniumsalts (QASs) have been widely used for disinfection purposes because of their low price, high efficacy and low human toxicity for decades. However, precise mechanisms of action nor the powerful versatile agent against all antimicrobial species are known. In this study we have prepared 43 novel N-alkyl monoquaternary ammoniumsalts including 7 N,N-dialkyl monoquaternary ammonium salts