RESUMEN
The ansacarbamitocins are a new family of maytansinoids that are unusually substituted with a glucose subunit and two carbamate functional groups and exhibit modest activity against some agricultural fungal disease organisms. Ansacarbamitocins A-F ( 1- 6) all consist of the same macrocyclic core as the ansamitocins, with variation occurring on the glucose unit, while ansacarbamitocins A1 and B1 ( 7, 8) additionally lack the epoxide group on C-4 and C-5.
Asunto(s)
Actinomycetales/química , Antibacterianos/aislamiento & purificación , Maitansina/análogos & derivados , Antibacterianos/química , Antibacterianos/clasificación , Antibacterianos/farmacología , Ascomicetos/efectos de los fármacos , Maitansina/química , Maitansina/clasificación , Maitansina/aislamiento & purificación , Maitansina/farmacología , Estructura Molecular , Relación Estructura-ActividadRESUMEN
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.
Asunto(s)
Cinamatos/análisis , Fungicidas Industriales/análisis , Pseudowintera/química , Sesquiterpenos/análisis , Cinamatos/química , Cinamatos/farmacología , Fungicidas Industriales/farmacología , Modelos Moleculares , Nueva Zelanda , Phytophthora/efectos de los fármacos , Extractos Vegetales/farmacología , Hojas de la Planta/química , Sesquiterpenos/química , Sesquiterpenos/farmacologíaRESUMEN
Bioassay-guided fractionation of the MeOH and EtOAc fractions of extracts of two lianas collected in Suriname has led to the isolation of five new diterpenoids, humirianthone 1, 1-hydroxy-humirianthone 2, 15R-humirianthol 3, patagonol 4, and patagonal 5, and the five known diterpenoids, humirianthol 7, annonalide 8, acrenol 9, icacinol 10, and the oxidized annonalide 11. All 10 diterpenoids showed cytotoxic activity against the A2780 human ovarian cancer cell line, and compounds 1, 3, 8, and 9 also showed activity against phytopathogenic fungi.