Study of the Anti-klebsiella Activity of Quinazoline Compounds Containing a Piperazine Ring

The aim of this study was to investigate the antimicrobial activity of piperazine ring-containing quinazoline compounds against Klebsiella pneumoniae. The study of antimicrobial activity was carried out in vitro via serial dilutions of the pyrimidine compound, with subsequent determination of the minimum inhibitory concentration. Screening for anti-Klebsiella activity was performed against pyrimidine derivatives of quinazolinone with a piperazine ring 1-methyl-3-[2-(4-methylpiperazino)-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–20–26), 1-methyl-3-[2-(4-phenylpiperazino)-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–20–27), 1,3-Di[2-(4-methylpiperazin-1yl)-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–20–29), 1,3-Di[2-(4-phenylpiperazin-1yl)-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–20–30), 1-Phenacin-3-[2-(4-phenylpiperazino)-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–20–41), 1-[2-(4-phenylpiperazino-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–24–04), synthesized by scientists from Volgograd State Medical University. A study of the antimicrobial activity of quinazoline compounds containing a piperazine ring against K. pneumoniae has established that the most active compounds exhibiting bacteriostatic activity at concentrations of 1 and 0.5 µg/ml and bactericidal activity at 4 and 16 µg/ml, comparable to ciprofloxacin, are 1-methyl-3-[2-(4-methylpiperazino)-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–20–26) and 1-[2-(4-phenylpiperazino-2-oxoethyl]quinazoline-2,4(1H,3H)-dione (VMA–24–04). The obtained results prompt further detailed studies of toxicity and pharmacological activity, including antimicrobial activity, both in vitro and in vivo .