Cytonic acids A and B: Novel tridepside inhibitors of hCMV protease from the endophytic fungus Cytonaema species

Two novel human cytomegalovirus protease inhibitors, cytonic acids A (1) an d B (2), have been isolated from the solid-state fermentation of the endoph ytic fungi Cytonaema sp. Their structures as p-tridepside isomers were eluc idated by MS and NMR methods.