Synthetic Studies Toward Nonribosomal Peptides

Profiling of Plant Growth-Promoting Metabolites by Phosphate-Solubilizing Bacteria in Maize Rhizosphere

Microbial treatment has recently been attracting attention as a sustainable agricultural strategy addressing the current problems caused by unreasonable agricultural practices. However, the mechanism through which microbial inoculants promote plant growth is not well understood. In this study, two phosphate-solubilizing bacteria (PSB) were screened, and their growth-promoting abilities were explored. At day 7 (D7), the lengths of the root and sprout with three microbial treatments, M16, M44, and the combination of M16 and M44 (Com), were significantly greater than those with the non-microbial control, with mean values of 9.08 and 4.73, 7.15 and 4.83, and 13.98 and 5.68 cm, respectively. At day 14 (D14), M16, M44, and Com significantly increased not only the length of the root and sprout but also the underground and aboveground biomass. Differential metabolites were identified, and various amino acids, amino acid derivatives, and other plant growth-regulating molecules were significantly enhanced by the three microbial treatments. The profiling of key metabolites associated with plant growth in different microbial treatments showed consistent results with their performances in the germination experiment, which revealed the metabolic mechanism of plant growth-promoting processes mediated by screened PSB. This study provides a theoretical basis for the application of PSB in sustainable agriculture.

Peptidomimetics - An infinite reservoir of metal binding motifs in metabolically stable and biologically active molecules

The involvement of metal ions in interactions with therapeutic peptides is inevitable. They are one of the factors able to fine-tune the biological properties of antimicrobial peptides, a promising group of drugs with one large drawback - a problematic metabolic stability. Appropriately chosen, proteolytically stable peptidomimetics seem to be a reasonable solution of the problem, and the use of D-, β-, γ-amino acids, unnatural amino acids, azapeptides, peptoids, cyclopeptides and dehydropeptides is an infinite reservoir of metal binding motifs in metabolically stable, well-designed, biologically active molecules. Below, their specific structural features, metal-chelating abilities and antimicrobial potential are discussed.