CHARACTERIZATION OF ANTIVIRAL ACTIVITY OF A SESQUITERPENE, TRIPTOFORDIN C-2

The activities of 13 sesquiterpenes isolated from Tripterygium wilford ii Hook hi. var. regelii Makino were studied against herpes simplex vi rus type 1 (HSV-1) in vitro. Among these compounds, only triptofordin C-2 showed a selectivity index of more than 10. The compound, which co uld also inhibit the replication of human cytomegalovirus (HCMV), did not affect either adsorption or penetration of HSV-1 to host cells, bu t showed moderate virucidal activity against several enveloped viruses including HSV-1, HCMV, measles virus and influenza A virus. Triptofor din C-2 suppressed viral protein synthesis of infected cells when adde d at early steps of HSV-1 replication and exerted inhibition of transl ation of the transcripts of the immediate early genes. When acyclovir and triptofordin C-2 were evaluated in combination for antiviral activ ity against HSV-I replication, additive antiviral effects were observe d for this virus.