Occurrence of isousnic acid in lichens with reference to “isodihydrousnic acid” derived from dihydrousnic acid

Nematocidal principles in "oakmoss absolute" and nematocidal activity of 2,4-dihydroxybenzoates

Nematocidal principles obtained from oakmoss absolute were identified as methyl 2,4-dihydroxy-3,6-di-methylbenzoate (2), ethyl 3-formyl-2,4-dihydroxy-6-methylbenzoate (4), and ethyl 5-chloro-3-formyl-2,4-dihydroxy-6-methylbenzoate (7). In relation to their structures, the nematocidal activity of 2,4-dihydroxybenzoates of methyl to tetradecyl was tested and the strongest activity was found in the octyl ester (minimal lethal concentration = 13 microM).

Isolation of (-)-cryptosporiospin, a chlorinated cyclopentenone fungitoxic metabolite from Phialophora asteris f. sp. helianthi

The (-)-enantiomer of cryptosporiopsin, a chlorinated cyclopentenone fungitoxic metabolite, was isolated from Phialophora asteris f. sp. helianthi. Next to a comparable fungitoxic activity was shown by crypstosporiopsin, the product particularly inhibits growth of Sclerotinia sclerotiorum, an important pathogen on sunflower. Two further metabolites were tentatively identified as a stereoisomer of cryptosporiopsin and its dehydrated derivative.