The complexation properties of some unnatural and natural macrocyclic trichothecenes

Abstract

As a result of investigating the complexing properties of a series of novel polyether analogues (3)–(9) of macrocyclic trichothecenes towards alkali metal cations and RNH₃⁺ ions, it has been proposed, with supporting evidence from X-ray crystallography on verrucarin A (1) and fast atom bombardment mass spectrometry of complexes involving (1) and the triacetate (10) of baccharinol B4 (11), that the enhanced biological activities of macrocyclic trichothecenes, such as (1) and (11), compared with non-macrocyclic trichoverroids such as (2), may be a consequence of their abilities to bind to NH₃⁺ ionic sites on proteins, particularly those associated with the 60S ribosomes.