Characterization of Chalkophomycin, a Copper(II) Metallophore with an Unprecedented Molecular Architecture

Abstract

Metals play essential roles in life by coordination with small molecules, proteins, and nucleic acids. Although the coordination of copper ions in many proteins and methanobactins is known, the coordination chemistry of Cu­(II) in natural products and their biological functions remain underexplored. Herein, we report the discovery of a Cu­(II)-binding natural product, chalkophomycin (CHM, 1), from Streptomyces sp. CB00271, featuring an asymmetric square-coordination system of a bidentate diazeniumdiolate and a conjugated 1H-pyrrole 1-oxide-oxazoline. The structure of 1 may inspire the synthesis of Cu­(II) chelators against neurodegenerative diseases or Cu­(II)-based antitumor therapeutics.

Degradation of mirubactin to multiple siderophores with varying Fe(iii) chelation properties

“…Mirubactin ( 1 ) was first isolated from Actinosynnema mirum , 11 while its structure was later revised through total synthesis. 18,19 During our continuing search for natural products from actinomycetes, 20–23 we rediscovered 1 from Streptomyces sp. CB02460 based on its Fe( iii )-chelating property using chrome azurol S assay 24,25 and HR-ESI-MS and MS/MS analyses (Fig.…”

“…synthesis. 18,19 During our continuing search for natural products from actinomycetes, [20][21][22][23] we rediscovered 1 from Streptomyces sp. CB02460 based on its Fe(III)-chelating property using chrome azurol S assay 24,25 and HR-ESI-MS and MS/MS analyses (Fig.…”

Three New Difunctional Electrocatalysts Built from Polyoxometalates and Cu–Tpy Units: Experimental and Theoretical Study

“…44 The asymmetric square-coordination configuration of the Cu(II)-binding natural product (chalkophomycin) can improve the application value of copper(II)− organic complexes in medical treatment. 45 in chemical constitution and catalytic activity was achieved using L-ascorbic acid as a chemical scalpel to fabricate the Cu I −1,4-benzenedicarboxylate complex. 46 The triangle-shaped 4′-(pyrrol-3-yl)-2,2′:6′,2″-terpyridine (abbreviated as tpy) has three features: (i) four N atoms from three pyridines and one imidazole ring can provide μ 3 -or μ 4 -coordination modes to graft metal ions; (ii) as a rigid ligand, the two sorts of N atoms of three adjacent N donors in three pyridines and one N atom from imidazole rings will lessen steric hindrance owing to long distance, N pyridine − N imidazole distances are in the range from 6.37 to 8.…”

Synthetic Approach to the Natural N-Nitrosohydroxylamino Tetramic Acid JBIR-141

“… These were the first natural compounds with complex structures that feature a delicate N -nitrosohydroxylamino (a.k.a. diazeniumdiolate) group, which is generally rare in nature. − In cell-based reporter assays, both compounds strongly inhibited the transcriptional activity of Foxo3a with IC 50 values of 23.1 nM (for 1 ) and 166.2 nM (for 2 ) while not affecting other transcription factors such as NF-κB, p53, and notch. This Foxo3a inhibition correlated nicely with a distinct cytotoxic effect of compounds 1 and 2 on three human cancer cell lines.…”