Growers of many fruit and ornamental crops have new weapons for fighting destructive fungi, thanks to Agricultural Research Service and University of Mississippi scientists who've transformed a medicinal compound into an agricultural fungicide.

The naturally occurring compound, called sampangine, was first patented by U of M in 1990 as a treatment for human fungal infections. It was never released pharmaceutically.

Now, plant pathologist David Wedge of ARS' Natural Products Utilization Research Unit and U of M associate professor Dale Nagle have been issued a patent for sampangine and similar, related compounds as broad-spectrum, low-toxicity controls of fungal plant pathogens that threaten agriculture.

The ARS unit and the university are both based in Oxford, Miss. ARS is the U.S. Department of Agriculture's chief scientific research agency.

According to the new patent — U.S. No. 6,844,353 — sampangine-based compounds can control such fungi as Botrytis cinerea, which causes gray mold on tomatoes; Colletotrichum fragariae, which produces anthracnose crown rot and wilt in strawberry plants; C. gloeosporioides, which sickens numerous plants, including grapes, strawberry, citrus and papaya; and Fusarium oxysporum, which induces vascular wilt in crops such as potato, sugarcane and many ornamentals.