Abstract: Arsanilic acid and TMP were utilized as the raw materials and then arsanilic acid-TMP was prepared. The new compound was characterized by IR and melting point. Orthogonal test showed that the best reaction condition was that being heated at 80 ℃ for 3 hours under reflux, and the molar ratio of arsanilic acid and TMP was 1.1∶1. The in vitro antibacterial indicated that the inhibitory zone diameter of arsanilic acid-TMP against the five kinds of tested bacteria is longer than 20 mm and arsanilic acid-TMP had greater bacteria-inhibiting effect than the physical mixture of arsanilic acid and TMP (P＜0.05); the minimum inhibitory concentration (MIC) of arsanilic acid-TMP against Escherichia coli, Staphylococus aureus,Salmonella pullorum,Shigella flexneri and Micrococcus luteus were 32,64,256,32,128 μg/mL, respectively, which were less than the MIC of the physical mixture of arsanilic acid and TMP. According to this study, arsanilic acid-TMP has greater antibacterial effect than arsanilic acid, TMP and their physical mixture.

Key words: arsanilic acid; TMP; in vitro antibacterial; inhibitory zone; minimum inhibitory concentration