Synthesis, Cytotoxic and Phytotoxic Effects of Some New N4-Aryl Substituted Isatin-3-thiosemicarbazones

A series of N4-aryl substituted isatin-3-thiosemicarbazones was prepared by the reaction of isatin with an appropriate thiosemicarbazide in ethanol containing a few drops of acetic acid. The newly synthesized compounds were characterized by means of their analytical (CHN) and spectral (IR, 1H-NMR, EIMS) data, and evaluated for their cytotoxicity and phytotoxicity potential. Eleven out of thirteen compounds tested proved to be active in the brine-shrimp lethality bioassay exhibiting significant cytotoxic activity with LD50 values ranging from 1.75x10-5M to 1.91x10-4M. In phytotoxicity assay, all the synthesized compounds, regardless of the nature of aryl substituents, demonstrated weak to moderate (5-30%) plant growth inhibition at the highest tested concentration (500 μg/mL).