Abstract: A method is provided to protect plants from oomycete pathogens by treating plants with a composition comprising serratamolide. The composition may also contain oocydin A obtained from Serratia marcescens MSU-97.

Abstract: Oocydin A is a mono-chlorinated lipophilic macrocyclic lactone that was isolated from a strain of Serratia marcescens that produces oocydin A in culture. Oocydin A has a molecular mass of 470, contains one atom of chlorine, a carboxyl group, and a tetrahydrofuran ring internal to a larger macrocyclic ring. Minimum inhibitory concentrations of circa 0.03 &mgr;g ml−1 were noted for oocydin A against phytopathogenic Oomycetes. Oocydin A can be used as an anti-Oomycete in agricultural applications for crop protection.

Abstract: A unique lipopeptide antimycotic, termed Cryptocandin, is described from Cryptosporiopsis cf quercina, an endophytic fungus. Cryptocandin with a molecular mass of 1079 contains equimolar amounts of 1,2-dihydroxy-homotyrosine, 4-hydroxy proline, threonine, glutamine, 3-hydroxy-4-hydroxy methyl proline, 4,5 dihydroxy ornithine, and palmitic acid. Cryptocandin is chemically related to well-known antimycotics, the echinocandins, and pneumocandins which are produced by such fungi as Zalerion arboricola, Pezicula spp., and Aspergillus spp. Cryptocandin has minimum inhibitory concentration values less than 0.03 &mgr;g ml−1 against isolates of Candida albicans, Trichophyton mentagrophytes and Trichophyton rubrum. Cryptocandin is also active against a number of plant pathogenic fungi including Sclerotinia sclerotiorum and Botrytis cinerea.