ABSTRACT
Seven new eremophilane-type sesquiterpenoids (1-5, 7, and 8) and the known mairetolide F (6) were isolated from the endophytic Xylaria sp. BCC 21097. A new furofurandione (9) was also isolated from the fungal extract. The structures of the new compounds were elucidated by analyses of NMR spectroscopic and mass spectrometry data in combination with chemical reaction studies. Eremophilanolides possessing an alpha-methylene-gamma-lactone (1-3) exhibited moderate cytotoxic activities, while related analogues bearing an endo double bond (6 and 7) were inactive.
Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Xylariales/chemistry , Animals , Antineoplastic Agents/pharmacology , Candida albicans/drug effects , Chlorocebus aethiops , Drug Resistance, Multiple/drug effects , Drug Screening Assays, Antitumor , Female , Humans , KB Cells , Microbial Sensitivity Tests , Molecular Structure , Mycobacterium tuberculosis/drug effects , Nuclear Magnetic Resonance, Biomolecular , Plasmodium falciparum/drug effects , Sesquiterpenes/pharmacology , Structure-Activity Relationship , Thailand , Vero CellsABSTRACT
Phruensis brunneispora is a new genus and species occurring on decaying trunks of the palm Licuala longecalycata in Sirindhorn Peat Swamp Forest, Thailand. We compare the genus with other aquatic ascomycetes with falcate septate ascospores: Pseudohalonectria and Ophioceras. Ascospores differ from species in these genera in being brown with lighter end cells. Also, the ascus pore is subapical, with a channel leading to the apex. Lollipopaia minuta differs from Phruensis brunneispora in that the ascomata are borne in a stroma, asci have an apical pore and the ascospores are hyaline. No genus was found to accommodate the new species. Molecular analysis of rDNA ribosomal 18S confirmed the exclusion of the new species from Pseudohalonectria, and Ophioceras and Lollipopaia minuta formed a sister group with it. Phruensis brunneispora and Lollipopaia minuta grouped in the Diaporthales with 100% bootstrap support. Therefore, both morphological and molecular evidence supports erecting a new genus to accommodate this taxon. A hyaline Phialophora-like anamorph was formed when single ascospores were plated out on agar. The taxon is described and illustrated with light micrographs.
