Enhanced toxicity of the immunosuppressant ovalicin upon application to the skin.

The non-myelotoxic immunosuppressive sesquiterpene ovalicin, of fungal origin, is much more toxic when applied to the skin of animals than when injected i.v., the LD-50 in guinea pigs being 0.2 in the first case and 7 mg/kg in the second. It elicits aphagia and adipsia. It is assumed that ovalicin effects are due to slow, tissue-specific, metabolic toxification.