Synthesis, Spectroscopy and in vitro Cytotoxicity of New Hydroxyanthraquinonato Triorganotin Compounds

Abstract

We will present herein data on the synthesis, structural investigation and in vitro antitumor activity of new triorganotin compounds of the general type (R3Sn)2Q, where R=Bu, Ph, Bz, Q1=1,4‐dihydroxy‐9,10‐anthracenedione (quinizarin), Q2=1,5‐dihydroxy‐9,10‐anthracenedione (anthrarufin), Q3=2,3‐dihydro‐9,10‐dihydroxy‐1,4‐anthracenedione (leucoquinizarin) and R3SnQ 4 where Q4=1,2‐dihydroxy‐9,10‐anthracenedione (alizarin). The compounds were synthesized by refluxing the organotin hydroxide with the parent quinone and were characterized by IR, 1H‐ NMR and thermal measurements. The spectroscopic analysis of the new triorganotins, provides evidence on the formation of a monodentate Sn‐O bond for quinizarin, anthrarufin and leucoquinizarin, which are coordinated to Sn(IV) central atom via the phenolic oxygen donor atoms, with the R‐substituents of the organotin moiety completing the tetrahedral coordination environment. On the contrary, organotin alizarinates form a six‐membered chelate ring, which stabilizes the Sn central atom in a five‐coordinated environment exhibiting distorted trigonal bipyramidal geometry. The ligand is coordinated to Sn (IV) via the quinoidal oxygen and its neighbouring phenolic one. The new compounds were tested for their cytotoxicity against human tumor and normal cell lines and the results are reported.