Two isomorphous clathrates formed by dihydrocyclosporin A or cyclosporin V
with tert-butyl methyl ether are reported and compared with the structures
of related P2(1)-symmetry cyclosporin clathrates. The cyclosporin molecules
in both structures are associated via van der Waals interactions forming c
avities occupied by solvent molecules (cyclosporin : tert-butyl methyl ethe
r is 1 : 2).