Solving the structural puzzle of bacterial glycome

Lipopolysaccharide O-antigen molecular and supramolecular modifications of plant root microbiota are pivotal for host recognition

“…This MAMPtriggered immunity controls the microbial load and, upon non-self-recognition, induces defense responses such as oxidative bursts, nitric oxide generation, extracellular pH increase, cell wall reinforcement, and accumulation of pathogenesis-related proteins to limit pathogen growth. MAMPs include proteins such as bacterial flagellin and elongation factor Tu as well as cell envelope components, like lipopolysaccharides (LPS) (Di Lorenzo, 2021;Wanke, 2021;Marchetti, 2021 ), beta-glucans (Wanke, 2020), peptidoglycan (Erbs, 2008), and fungal chitin (Hayafune, 2014).…”

Expanding Knowledge of Methylotrophic Capacity: Structure and Properties of the Rough-Type Lipopolysaccharide from Methylobacterium extorquens and Its Role on Membrane Resistance to Methanol

“…The NMR spectra revealed the presence of 14 sugar units, all present as pyranose rings, according to both 13 C chemical shift values and long-range correlations between C-1/H-1 and H-5/C-5 in the 1 H and 13 C HMBC spectrum (for the Kdo/Ko residues between C-2 and H-6) ( Table S1 , Figures 1 , and S2–S4 ). 18 …”

“…The NMR spectra revealed the presence of 14 sugar units, all present as pyranose rings, according to both 13 C chemical shift values and long-range correlations between C-1/H-1 and H-5/C-5 in the 1 H and 13 C HMBC spectrum (for the Kdo/Ko residues between C-2 and H-6) (Table S1, Figures 1, and S2−S4). 18 Spin systems A, B, and F were identified as galacto configured sugar units, as indicated by the 3 J H3,H4 and 3 J H4,H5 values (3 and <1 Hz, respectively). Both 3 J H1,H2 and 1 J CH coupling constant values, together with intra-residual NOE contact of H-1 with H-2, were diagnostic of their αconfigurations and 4 C 1 ring conformation.…”

A De Novo Route to 3,6-Dideoxy Sugars

“…Compared to the parent hexose/6-deoxy hexose, there was a substantial increase in the amount of the furanose forms. This was most pronounced for paratose (2) and tyvelose (3) where the furanose forms increased from <1% in the hexose/ 6-deoxy-hexose to ≥17% in the 3,6-dideoxy-hexose (23% in the case of 3). These trends are expected as C3 deoxygenation would eliminate torsional/steric strain in the furanose forms.…”

“…A range of important bioactive natural products contain deoxygenated and other diversely functionalized carbohydrates. − One example, 3,6-dideoxy sugars, decorate the lipopolysaccharide of some Salmonella and other Gram-negative bacteria with the specific monosaccharideabequose ( 1 , Figure ), paratose ( 2 ), or tyvelose ( 3 )often defining the immunogenic epitope . 3,6-Dideoxy sugars are also critical components of the ascarosides, nematode-signaling molecules …”