Discovery and structure elucidation of glycosyl and 5-hydroxy migrastatins from dung beetle gut Kitasatospora sp.

Unlabelled: Two new macrocyclic secondary metabolites, glycosyl-migrastatin (1) and 5-hydroxy-migrastatin (2), were isolated from a gut bacterium Kitasatospora sp. JL24 in dung beetle Onthophagus lenzii. Based on a comprehensive analysis of the nuclear magnetic resonance (NMR), MS, and UV spectroscopic data, the planar structures of 1 and 2 were successfully identified as new derivatives of migrastatin.

Asymmetric Synthesis of Four Stereoisomers of 2,2-Dimethyl-3-hydroxy-4-(1'-angeloyloxy)-6-acetylchromane from and Plausible Absolute Stereochemistry of the Natural Product.

2,2-Dimethyl-3-hydroxy-4-(1'-angeloyloxy)-6-acetylchromane is a natural product isolated from that exhibits inhibitory activity against yeast α-glucosidase. Initially, its structure was proposed to be 4-hydroxy-3-(()-1'-angeloyloxy-()-2',3'-epoxy-3'-methyl)butylacetophenone with an epoxide, but the structure was later revised to 2,2-dimethyl-3-hydroxy-4-(1-angeloyloxy)-6-acetylchromane. In this study, we present a total synthesis of 2,2-dimethyl-3-hydroxy-4-(1'-angeloyloxy)-6-acetylchromane from and its stereoisomers.

Targeted and Logical Discovery of Piperazic Acid-Bearing Natural Products Based on Genomic and Spectroscopic Signatures.

A targeted and logical discovery method was devised for natural products containing piperazic acid (Piz), which is biosynthesized from ornithine by l-ornithine -hydroxylase (KtzI) and - bond formation enzyme (KtzT). Genomic signature-based screening of a bacterial DNA library (2020 strains) using polymerase chain reaction (PCR) primers targeting identified 62 strains (3.1%).

Jejucarbosides B-E, Chlorinated Cycloaromatized Enediynes, from a Marine sp.

Four new chlorinated cycloaromatized enediyne compounds, jejucarbosides B-E (-), were discovered together with previously-identified jejucarboside A from a marine actinomycete strain. Compounds - were identified as new chlorinated cyclopenta[]indene glycosides based on 1D and 2D nuclear magnetic resonance, high-resolution mass spectrometry, and circular dichroism (CD) spectra. Jejucarbosides B and E bear a carbonate functional group whereas jejucarbosides C and D are variants possessing 1,2-diol by losing the carbonate functionality.

Targeted Discovery of an Enediyne-Derived Cycloaromatized Compound, Jejucarboside A, from a Marine Actinomycete.

A genomic and spectroscopic signature-based search revealed a cycloaromatized enediyne, jejucarboside A (), from a marine actinomycete strain. The structure of was determined as a new cyclopenta[]indene glycoside bearing carbonate functionality by nuclear magnetic resonance, high-resolution mass spectrometry (MS), MS/MS, infrared spectroscopy, and a modified Mosher's method. An iterative enediyne synthase pathway has been proposed for the putative biosynthesis of by genomic analysis.

Nyuzenamide C, an Antiangiogenic Epoxy Cinnamic Acid-Containing Bicyclic Peptide from a Riverine sp.

A new nonribosomal peptide, nyuzenamide C (), was discovered from riverine sediment-derived sp. DM14. Comprehensive analysis of the spectroscopic data of nyuzenamide C () revealed that has a bicyclic backbone composed of six common amino acid residues (Asn, Leu, Pro, Gly, Val, and Thr) and four nonproteinogenic amino acid units, including hydroxyglycine, β-hydroxyphenylalanine, -hydroxyphenylglycine, and 3,β-dihydroxytyrosine, along with 1,2-epoxypropyl cinnamic acid.