ISOLATION AND SEQUENCE-ANALYSIS OF THE PEPTIDE ANTIBIOTICS TRICHORZINS PA FROM TRICHODERMA-HARZIANUM

Trichorzins PA are new members of the class of natural Aib-containing peptides, which are known under the common name peptaibols. They are p roduced by a Trichoderma harzianum strain and exhibit significant acti vity against mycoplasmas. From the natural peptide mixture, seven tric horzins PA (PA II and IV-IX) have been isolated by a procedure employi ng different chromatography steps and a final purification by reversed -phase HPLC. The amino acid sequence elucidation involved a combinatio n of liquid secondary-ion mass spectrometry (LSIMS) and two-dimensiona l H-1 and C-13 NMR spectroscopy Trichorzins PA are Is-residue peptaibo ls which differ mainly from other, related peptides by the C-terminal amino alcohol which is either tryptophanol or phenylalaninol. They ado pt a helical structure.