OCCURRENCE OF CYCLOSPORINES AND CYCLOSPORINE-LIKE PEPTOLIDES IN FUNGI

Apart from 17 previously listed fungal taxa producing cyclosporin A an d its natural congeners B to Z, several additional and taxonomically d iverse strains producing the single novel component [Thr(2), Leu(5),Le u(10)]cyclosporin or cyclosporin-like peptolides (eg SDZ 214-103 = [Th r(2),Leu(5),D-Hiv(8),Leu(10)]cyclosporin) have recently been described , We report here the isolation of two further and novel cyclosporins, [Thr(2), Leu(5),Ala(10)]cyclosporin (2) and [Thr(2),lle(5)]cyclosporin (3), from strains classified as Acremonium luzulae (Fuckel) W Gams an d Leptostroma anamorph of Hypoderma eucalyptii Cooke & Harkn, respecti vely, In both new strains the usual pattern of cyclosporins A to Z is not found, The structure elucidations of 2 and 3 are based on NMR spec troscopy, and biological data (immunosuppressive activity, cyclophilin -binding affinity and antifungal effects) are presented.