Simplicissin, a New Pollen Growth Inhibitor Produced by the Fungus, Penicillium cf. simplicissimum (Oudemans) Thom No. 410.

A new pollen growth inhibitor, named simplicissin, was isolated from Penicillium cf. simplicissimum (Oudemans) Thom No. 410, and its structure was established by spectroscopic methods including 2D NMR. The biological activities of the compound were examined by the bioassay methods involving tea pollen together with lettuce seedlings. The compound inhibited the growth of the tea pollen tube by 45% at a concentration of 3 mg/liter and showed complete inhibition at 10 mg/liter.