Rhodopyran, a carboxylated hexahydrocyclopenta[b]pyran from Rhodococcus

Area of Science:

• Microbiology
• Natural Product Chemistry
• Organic Chemistry

Background:

• Rhodococcus species are known producers of diverse secondary metabolites.
• Exploring microbial metabolites can lead to the discovery of novel chemical scaffolds.

Purpose of the Study:

• To isolate and characterize new metabolites from Rhodococcus sp. strain RD066637.
• To investigate the structural novelty and diversity of metabolites produced by Rhodococcus.

Main Methods:

• Isolation of metabolites from bacterial culture broth.
• Structure elucidation using 1D/2D Nuclear Magnetic Resonance (NMR) spectroscopy.
• High-resolution Mass Spectrometry (HRMS) for molecular formula determination.
• Analysis of Nuclear Overhauser Effect SpectroscopY (NOESY) correlations and vicinal coupling constants for relative configuration assignment.

Main Results:

• A new bicyclic metabolite, rhodopyran (1), was successfully isolated.
• The planar structure of rhodopyran was determined through comprehensive NMR and HRMS analyses.
• The relative configuration of rhodopyran was assigned, though its absolute configuration remains undetermined.
• Rhodopyran was identified as a structurally unique carboxylated hexahydrocyclopenta[b]pyran.

Conclusions:

• Rhodopyran represents a novel natural product scaffold.
• The discovery of rhodopyran expands the known metabolite diversity of Rhodococcus species.
• Rhodococcus bacteria are a valuable source for identifying uncommon natural product structures.