Study of acute oral toxicity of organotin compounds containing a 2,6-di-tert-butylphenol fragment

The aim of the study was to evaluate the safety of the use of organotin compounds containing a fragment of 2,6-di-tert-butylphenol as pharmaceutical substances when administered intragastrically to Wistar outbred rats (females). Material and methods. The objects of the study were three organotin compounds: ((3,5-di-tertbutyl-4-hydroxyphenylthiolate) triphenyltin (Me-5), (3,5-di-tert-butyl-4-hydroxyphenylthiolate)trimethyltin (Me-4), bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate) dimethyltin (Me-3). Acute toxicity study were performed on 106 Wistar rats (female) weighing 190-210 g by "fixed dose" and "up and down" methods according to the OECD protocols. Results. According to the harmonized system of hazard classification and labeling of chemical products (GHS) the studied organotin compounds should be assigned to the following toxicity classes: Me-5 — IV, Me-3 — V, Me-4 — II. Average lethal dose in intragastric administration for Me-5 is LD50 = 955.0 ± 58.3 mg/kg, the value of LD50 for Me-3 is conventionally assumed to be much more than 2000 mg/kg, for Me-4 is in the range of 5 to 50 mg/kg. Discussion. The modification of tin-organic molecules in the course of directed synthesis opens broad prospects for the creation of a new class of anticancer drugs. In the course of the experimental study, the regularities of the "structure-toxicity" relationship of organic tin derivatives were revealed: the introduction of the 2,6-di-tert-butylphenol group significantly reduces toxicity compared to the corresponding initial substances; methyl derivatives are more toxic than their phenyl analogues. Compounds of GHS toxicity classes IV and V can be considered as leading candidates for promising preclinical studies in the field of experimental oncology. Conclusion. Substances of Me-3 and Me-5, which have the highest safety for intragastric use, were recommended for further study as antitumor drug agents.