Structure-based manual screening and automatic networking for systematically exploring sansanmycin analogues using...

Area of Science:

• Natural Product Chemistry
• Microbiology
• Analytical Chemistry

Background:

• Sansanmycins (SS) are uridyl peptide antibiotics (UPAs) with a unique scaffold.
• UPAs exhibit inhibitory effects against refractory pathogens like Pseudomonas aeruginosa and multi-drug resistant Mycobacterium tuberculosis.

Purpose of the Study:

• To explore and identify novel sansanmycin analogues from Streptomyces sp. SS fermentation broth.
• To compare the efficacy of manual and automated structure-based screening methods for UPA discovery.

Main Methods:

• High-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) with ion trap and LTQ orbitrap analyzers.
• Structure-based manual screening utilizing fragmentation pathway analysis and MS/MS spectra comparison.
• GNPS-based molecular networking for automated re-analysis of HPLC-MS/MS data.

Main Results:

• Identification of twenty sansanmycin analogues, including twelve new structures (1-12) via manual screening.
• Discovery of eight additional new sansanmycins (13-20) using the GNPS networking workflow.
• Characterization of novel structural features, including dehydrated enamine-uridyl and dihydro-aminouridyl moieties in newly identified compounds.

Conclusions:

• HPLC-MS/MS, complemented by manual and networking methods, is efficient for exploring novel UPAs.
• The study expands the known diversity of sansanmycins, revealing unique structural variations.
• The identified novel UPAs hold potential for combating challenging bacterial infections.