Preparation of a new carboranyl lactoside for the treatment of cancer by boron neutron capture therapy: Synthesis and toxicity of fluoro carboranyl glycosides for in vivo F-19-NMR spectroscopy

The synthesis of new ortho-carboranyl lactosides 8, 17, 19 and glucosides 2 2 and 23 for the use in boron neutron capture therapy is reported. Carboran yl lactosides 17 and 19 as well as the glucosides 22 and 23 contain a fluor ine atom to allow a noninvasive determination of these compounds in tumor c ells by F-19-NMR spectroscopy. In cloning efficiency tests on human bronchi al carcinoma cells the carboranyl lactosides 17 and 19 displayed almost no cytotoxicity. Thus, the considerably cytotoxic carboranyl alcohol 11 is det oxified when linked to a sugar moiety such as in carboranyl glucoside 22.