cyclosporins cyclosporins the cyclosporins are a group of macrolides isolated from fungi and used as immunosuppresant drugs, for example after transplant surgery. they are nonribosomal peptide synthesized by cyclosporin synthetase. cyclosporin a (ciclosporin) cyclosporin b cyclosporin c cyclosporin d cyclosporin e cyclosporin f cyclosporin g