Structure and synthesis of an immunoactive lipopeptide, WS1279, of microbial origin

A sulfur-33 nuclear quadrupole resonance study of 33 S2 -labeled L-cystine

The sulfur electric-field-gradient tensor for a disulfide bond in ³³ S₂ -labeled L-cystine has been investigated by ³³ S nuclear quadrupole resonance (NQR). ³³ S₂ -labeled L-cystine is synthesized by introduction of disulfide ions prepared from elemental ³³ S-sulfur into an amino acid derivative, the side chain of which is iodinated. In its NQR spectrum, sharp single peaks are observed at between 24.63 and 24.90 MHz in the temperature range from 80 to 298 K. The two-dimensional nutation echo ³³ S NQR experiment is carried out at 160 K, and the quadrupole coupling constant, C_Q , and the asymmetric parameter, η_Q , are obtained to be 46.9(9) MHz and 0.6(1), respectively. The calculated ³³ S electric-field-gradient tensor components with respect to the molecular frame is briefly discussed.

Structural diversity, biosynthesis, and biological functions of lipopeptides from Streptomyces

Covering: up to 2022Streptomyces are ubiquitous in terrestrial and marine environments, where they display a fascinating metabolic diversity. As a result, these bacteria are a prolific source of active natural products. One important class of these natural products is the nonribosomal lipopeptides, which have diverse biological activities and play important roles in the lifestyle of Streptomyces. The importance of this class is highlighted by the use of related antibiotics in the clinic, such as daptomycin (tradename Cubicin). By virtue of recent advances spanning chemistry and biology, significant progress has been made in biosynthetic studies on the lipopeptide antibiotics produced by Streptomyces. This review will serve as a comprehensive guide for researchers working in this multidisciplinary field, providing a summary of recent progress regarding the investigation of lipopeptides from Streptomyces. In particular, we highlight the structures, properties, biosynthetic mechanisms, chemical and chemoenzymatic synthesis, and biological functions of lipopeptides. In addition, the application of genome mining techniques to Streptomyces that have led to the discovery of many novel lipopeptides is discussed, further demonstrating the potential of lipopeptides from Streptomyces for future development in modern medicine.