Abstract: The present invention relates firstly to the discovery of the previously unknown 24-membered cyclooctadepsipeptides PF1022-V, PF1022-W, XRB-C894, XRB-C942, XRB-C976, XRB-C1010, XRB-C1044, XRB-E922, XRB-E956, XRB-E990, XRB-E1024, XRB-S958, XRB-S992, XRB-S1026, XRB-S1060 (in various isomeric forms) and to the processes for the preparation of the abovementioned cyclooctadepsipeptides by means of the fungal strains from the family Xylariaceae, in particular the genera Rosellinia and Coniolariella, and by means of the mitosporic fungal strains from the groups Fusarium, Beauveria and Verticillium (orders Hypocreales and Phyllachorales), and by means of the enzymatic preparations isolated from these fungal strains, and secondly to the use of these strains for the preparation of the abovementioned novel cyclooctadepsipeptides and to the use of bassianolide and of the abovementioned novel cyclooctadepsipeptides individually or as a mixture, as anthelmintics or endoparasiticides.

Abstract: The present invention relates to a process for the preparation of lactic- and phenyllactic-acid-containing, optically active, cyclic depsipeptides with 24 ring atoms by means of fungal strains of the genus Rosellinia and further Xylariaceae isolated not only from fruiting bodies of Rosellinia spp. and Xylariaceae growing on dead timber and live timber of deciduous and coniferous trees, but also directly from timber and roots of deciduous and coniferous trees, or by means of enzymatic preparations isolated from these fungal strains. PF1022A, of the general formula (I), is outstandingly suitable for controlling endoparasites, in particular in the field of medicine and veterinary medicine.