Synthesis of a brucine-dihydropyrimidine derivative using the multi-component system

In this study, abrucine derivatives was synthesized. The route involved preparation of a brucine-dihydropyrimidine derivative using brucine, benzaldehyde and thiourea in the presence of hydrochloric acid. The antibacterial activity of brucine derivative was evaluated in vitro with both Gram positive and Gram negative bacteria using the dilution method and the minimum inhibitory concentration. The results indicate that 1H NMR spectrum of brucine derivative showed signals at 385 and 391 ppm for methoxy groups at 7.31-7.40 ppm for phenyl group bound to dihydropyrimidine ring at 5.25 (-CH) and 7.60 ppm (-NH) involved in the dihydropyrimidine ring. Other results showed that bacterial growth of Salmonella typhi was inhibited by the compounds brucine derivative in a dose-dependent manner. Nevertheless, the bacterial growth of V. cholerae, E. coli, K. pneumoniae and S. aureus was not blocked by the brucine derivative. All these data indicate that the brucine derivative only induces antibacterial activity against S. tiphy; this phenomenon possibly can be due to expression of a dihydropyrimidine amidohydrolase, which could exert enzymatic activity on the dihydropyrimidine ring of brucine derivative in V. cholerae, E. coli, K. pneumoniae and S. aureus, which brings consequently that bacterial growth of this microorganism is not inhibited.