Homotyrosine-Containing Cyanopeptolins 880 and 960 and Anabaenopeptins 908 and 915 from Planktothrix agardhii CYA 126/8

Two homotyrosine-bearing cyanopeptolins are described from Planktothrix agardhii CYA 126/8. The compounds feature a common homotyrosine-containing cyclohexadepsipeptide and differ by sulfation of an exocyclically located 2-O-methyl-D-glyceric acid residue. In addition we describe two anabaenopeptins, which contain two homotyrosine residues, one of which is N-methylated. The anabaenopeptins have a common cyclopentapeptide portion and differ in the amino acid linked to it via an ureido bond, arginine and tyrosine, respectively.