Carbazole and Quinazolinone Derivatives from a Fluoride-Tolerant Strain OUCMDZ-5511.

Six new 9-carbazole derivatives (-) and nine previously reported compounds (-) were isolated from a fermented solid medium of the Thailand mangrove-derived strain, OUCMDZ-5511, under fluoride stress. Compounds -, , and were exclusively present in the fluoride-supplemented fermentation medium, while compounds -, , and were newly discovered natural products. The molecular structures of the compounds were identified by a spectroscopic analysis.

Chimeric natural products derived from medermycin and the nature-inspired construction of their polycyclic skeletons.

Medermycin, produced by Streptomyces species, represents a family of antibiotics with significant activity against Gram-positive pathogens. The biosynthesis of this family of natural products has been studied, and new skeletons related to medermycin have rarely been reported until recently. Herein, we report eight chimeric medermycin-type natural products with unusual polycyclic skeletons.

Bioactive Metabolites From Acid-Tolerant Fungi in a Thai Mangrove Sediment.

Despite being potentially useful extremophile resources, there have been few reports on acid-tolerant fungi and their bioactive metabolites. Acidophilic/aciduric fungi ( = 237) were isolated from Thai mangrove sediments in an acidic medium. Using fungal identification technology (including morphologic observation, chemical screening, and sequence comparisons) all the isolates were identified and 41 representative isolates were selected for analysis of the phylogenetic relationships (ITS rDNA, β-tubulin, calmodulin, and actin gene sequences).