Modular Synthetic Approach to Carboranyl‒Biomolecules Conjugates

oleh: Martin Kellert, Jan-Simon Jeshua Friedrichs, Nadine Anke Ullrich, Alexander Feinhals, Jonas Tepper, Peter Lönnecke, Evamarie Hey-Hawkins

Format: Article
Diterbitkan: MDPI AG 2021-04-01

Deskripsi

The development of novel, tumor-selective and boron-rich compounds as potential agents for use in boron neutron capture therapy (BNCT) represents a very important field in cancer treatment by radiation therapy. Here, we report the design and synthesis of two promising compounds that combine <i>meta</i>-carborane, a water-soluble monosaccharide and a linking unit, namely glycine or ethylenediamine, for facile coupling with various tumor-selective biomolecules bearing a free amino or carboxylic acid group. In this work, coupling experiments with two selected biomolecules, a coumarin derivative and folic acid, were included. The task of every component in this approach was carefully chosen: the carborane moiety supplies ten boron atoms, which is a tenfold increase in boron content compared to the <span style="font-variant: small-caps;">l</span>-boronophenylalanine (<span style="font-variant: small-caps;">l</span>-BPA) presently used in BNCT; the sugar moiety compensates for the hydrophobic character of the carborane; the linking unit, depending on the chosen biomolecule, acts as the connection between the tumor-selective component and the boron-rich moiety; and the respective tumor-selective biomolecule provides the necessary selectivity. This approach makes it possible to develop a modular and feasible strategy for the synthesis of readily obtainable boron-rich agents with optimized properties for potential applications in BNCT.