The biological properties of cyclopenin and cyclopenol [isolated from Penicillium cyclopium]

Cyclopenin (C17H14O3N2) and cyclopenol (C17H14O4N2), isolated from an abberent strain of Penicillium cyclopium (NRRL 6233), significantly inhibited the growth of etiolated wheat (Triticum aestivum) coleoptile segments. The former inhibited at 10−3 and 10−4 m, the latter at 10−3 m. Cyclopenin produced malformation of the first set of trifoliate leaves in bean (Phaseolus vulgaris) at 10−2 m and necrosis and stunting in corn (Zea mays) at 10−2 m. Cyclopenol induced no apparent effects in bean or corn plants. Neither compound changed the growth or morphology of tobacco (Nicotiana tabacum) plants. Cyclopenin induced intoxication, prostration and ataxia in day-old chicks at 500 mg/kg, but they recovered within 18 hours. Cyclopenol was inactive against chicks when dosed at levels up to 500 mg/kg.