Synthesis and bioactivities of novel pyrazole oxime derivatives containing a 1,2,3-thiadiazole moiety

A series of new pyrazole oxime compounds bearing a 1,2,3-thiadiazole ring were designed, synthesized, and evaluated for their insecticidal, acaricidal and antitumor activities. Bioassays demonstrated that some title compounds displayed satisfactory insecticidal and acaricidal properties. Especially, compounds 8d and 8h exhibited 90% insecticidal activities against Aphis craccivora at the concentration of 100μg/mL. Interestingly, some of the target compounds possessed significant antitumor activities against four human cancer cell lines in vitro. Among them, compounds 8e (IC50=7.19μM), 8l (IC50=6.56μM), 8m (IC50=8.12μM), and 8r (IC50=7.06μM) had better inhibitory activities against HCT-116 cells than the control 5-fluorouracil (IC50=29.50μM). Additionally, compounds 8j, 8m, and 8r showed wonderful inhibitory activities against SGC-7901 cells with the IC50 values of 11.46, 9.41, and 8.64μM, respectively, which were superior to that of the control 5-fluorouracil.