Trichothecene structure and toxicity to the green alga Chlorella pyrenoidosa.

Using the paper-disk method with Chlorella-seeded agar plates, 15-acetoxyscirpenol, HT-2 toxin, acetyl T-2 toxin and neosolaniol inhibited growth at a concentration of 1 mg/ml, whereas verrucarol, T-2 tetraol, nivalenol, fusarenon-X, deoxynivalenol and 3-acetyldeoxynivalenol were inactive. Taking into account that verrucarin A, roridin A, T-2 toxin and diacetoxyscirpenol had previously been found to strongly inhibit Chlorella growth, esterification at R15 appears to be important for growth inhibitory activity. The most active agents are also esterified at R4. Inhibition of protein synthesis appears to be involved in the toxicity.