ORLANDIN - NONTOXIC FUNGAL METABOLITE WITH PLANT-GROWTH INHIBITING PROPERTIES

A new metabolite, bis[8, 8-(7-hydroxy-4-methoxy-5-methylcoumarin)], trivial name orlandin, was isolated from Aspergillus niger found growing on orange leaves. It was nontoxic to day-old cockerels but significantly inhibited wheat coleoptile growth at 103, 104, and 105 M. Orlandin may be a precursor of kotanin, bis[8, 8-(4, 7-dimethoxy-5-methylcoumarin)], isolated from Aspergillus clavatus. The latter was toxic to day-old cockerels, but did not inhibit the growth of wheat coleoptiles. © 1979, American Chemical Society. All rights reserved.