ABSTRACT
Bioactivity-directed separation of a foliage extract from the New Zealand shrub Pseudowintera axillaris led to a compound with fungicidal activity against the plant pathogen Phytophthora infestans. This was identified as a new sesquiterpene dialdehyde cinnamate named paxidal. Two 6-hydroxy derivatives were present at lower levels in the extract. A further nine derivatives were synthesized from these natural products for a structure-activity study against a range of important food crop pathogens. The cinnamate group was important for fungicidal effects, and protection of the dialdehyde as a dimethyl acetal gave more potent, broader spectrum activity.
Subject(s)
Cinnamates/analysis , Fungicides, Industrial/analysis , Pseudowintera/chemistry , Sesquiterpenes/analysis , Cinnamates/chemistry , Cinnamates/pharmacology , Fungicides, Industrial/pharmacology , Models, Molecular , New Zealand , Phytophthora/drug effects , Plant Extracts/pharmacology , Plant Leaves/chemistry , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacologyABSTRACT
A new member of the tartrolone series of macrodiolides, tartrolone C (1), was isolated from a Streptomyces species on the basis of its insecticidal activity. Metacycloprodigiosin (2) and undecylprodigiosin (3) were also isolated on the same basis. The structure of all compounds was established by spectroscopic data (NMR, MS, and UV).
