Antineoplastic and antiviral activities of some cyclolignans.

Nineteen cyclolignans of varied structures, most of them isolated from Juniperus sabina leaves, were evaluated for their antineoplastic and antiviral activities. They were subjected to screening against P-388 murine leukemia, A-549 human lung carcinoma, and HT-29 colon carcinoma, while the antiviral assays were performed on herpes simplex virus type 1 infecting fibroblasts of monkey kidney (HSV-1/CV-1) and on vesicular stomatitis virus infecting fibroblasts of hamster kidney (VSV/BHK). A number of substances were active in both types of assays at concentrations below 1 microgram/ml; deoxypodophyllotoxin and beta-peltatin A methyl ether being the most potent compounds in all cases, with IC50 values in the range 2.5-4 ng/ml for the three neoplastic systems.