Disclosure of new and recurrent microbial metabolites by mass spectrometric methods

The application of modern mass spectrometry methods (SI-CID-MS/MS; MSn) in the disclosure of new and recurrent microbial metabolites is discussed. Spr ay ion (SI) sources coupled to different kinds of mass analyzers enable the determination of molecular weights and chemical formulas of given samples even in mixtures. Diagnostic fragment formation by collision-induced dissoc iation (CID-MS/MS) and MSn experiments using ion trap mass analyzers are sh own as another indispensable source of structural information. Due to the d evelopment of benchtop-type mass spectrometers coupled to high-performance liquid chromatography (HPLC), MS can be practised in almost every laborator y as a powerful tool in natural product analysis. Examples are given for sp ecial MS applications in identification of bioactive metabolites from scree ning strains.