Cercospora beticola toxins. NMR studies and chemical behaviour

In this paper we have gathered NMR data on a series of identified beticolins, as well as the chemical and spectroscopic criteria allowing the differentiation of o- and p-beticolins. Spectroscopic criteria are based on the observation of characteristic nOe’s for both forms, whilst chemical criteria are derived from the behaviour of beticolins when exposed to a basic medium and from their ability to form stable dimers binding two Mg atoms.