Oxandrastins: Antibacterial Meroterpenes from an Australian Mud Dauber Wasp Nest-Associated Fungus, Penicillium sp. CMB-MD14

Miniaturized Cultivation Profiling Returns Indolo-Sesquiterpene Michael Adducts from the Australian Soil-Derived Aspergillus terreus CMB-SWF012

An integrated program of chemical profiling (GNPS) coupled with an expanded format 24-well-plate miniaturized cultivation profiling (MATRIX) utilizing traditional as well as grain/pulse and cereal media permitted rapid prioritization of Aspergillus terreus CMB-SWF012 as a source of unprecedented natural products. Scaled-up cultivation on rice and PDA yielded the rare tripeptides asterripeptides A-C (1-3), new indolo-sesquiterpene Michael adducts terreusides A and B (4 and 5), and known precursors asterresin A (6) and (+)-giluterrin (7). Structures for 1-7 were assigned by detailed spectroscopic and chemical analysis and biosynthetic considerations.

Glyclauxins A-E: Dimeric Oxaphenalenone Aminoglycosides from an Australian Wasp Nest-Derived Fungus Talaromyces sp. CMB-MW102

Chemical analysis of cultures of a Queensland mud dauber wasp nest-derived fungus, Talaromyces sp. CMB-MW102, yielded the known dimeric oxaphenalenone duclauxin (1) along with a family of new 1-deoxy-d-glucosamine adducts, glyclauxins A-E (2-6). Despite 1D NMR spectra of 2-6 being compromised by broadening of selected resonances, structures inclusive of absolute configuration were assigned on the basis of detailed spectroscopic analysis and biogenetic considerations, as well as biomimetic semisynthesis and chemical interconversion. For example, exposure of duclauxin (1) to synthetic 1-deoxy-d-glucosamine yielded glyclauxin B (3), while on handling and storage, glyclauxins C (4) and D (5) (bearing a 7-OMe moiety) proved chemically labile and underwent quantitative transformation to glyclauxins B (3) and A (2), respectively. These latter observations on chemical reactivity and stability informed a proposed biogenetic relationship linking all known members of the extended duclauxin family. Notwithstanding their potential status as artifacts, the detection of glyclauxins B (3) and A (2) in a fresh CMB-MW102 culture extract confirmed their natural product status.

Phoslactomycins Revisited: Polyketide Tetrahydrofurans and Lactones from an Australian Wasp Nest-Derived Streptomyces sp. CMB-MW079

Molecular network analysis of Streptomyces sp. CMB-MW079 detected rare phosphorylated natural products. Miniaturized cultivation profiling (MATRIX) established optimal conditions for the production, isolation, and identification of the polyketide δ-lactone phoslactomycin E (1) and new ester homologues, phoslactomycins J and K (2 and 3), as well as unprecedented heterocyclic analogues, the tetrahydrofuran cyclolactomycins A-D (4-7) and γ-lactone isocyclolactomycins A-C (8-10). We propose a biogenetic relationship linking these cometabolites with the known lactomycins A-C which were tentatively identified as minor cometabolites.