1.Structure of the O-specific polysaccharide from a marine bacterium Echinicola pacifica КММ 6172(Т) containing 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid.
Tomshich SV1, Kokoulin MS2, Kalinovsky AI2, Nedashkovskaya OI2, Komandrova NA2. Carbohydr Res. 2016 Apr 29;425:22-7. doi: 10.1016/j.carres.2016.03.003. Epub 2016 Mar 14.
The O-polysaccharide was isolated from the lipopolysaccharide of Echinicola pacifica KMM 6172(T) and studied by chemical analyses along with (1)H and (13)C NMR spectroscopy, including (1)H, (1)H COSY, 1D and 2D TOCSY, ROESY, (1)H, (13)С HMQC, HMBC and H2BC experiments. It was found that the polysaccharide is built up of branched pentasaccharide repeating units, containing D-galactose (Gal), L-rhamnose (Rha), 2-acetamido-2-deoxy-D-glucose (GlcNAc), two residues of 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (GlcNAc3NAcA) and O-acetyl group in nonstoichiometric amount and has the following structure.
2.Synthesis and plant growth regulation activity of α-d-ManpNAc-(1→2)-[α-L-Rhap-(1→3)-]α-L-Rhap-(1→4)-β-d-GlupNAc-(1→3)-α-L-Rhap, the repeating unit of O-antigen of Rhizobium trifolii 4s.
Zong G1, Liang X1, Zhang J2, Duan L3, Tan W4, Wang D1. Carbohydr Res. 2014 Mar 31;388:87-93. doi: 10.1016/j.carres.2013.12.006. Epub 2013 Dec 12.
The synthesis of a pentasaccharide 2 containing acetamido-2-deoxy-d-glucose and acetamido-2-deoxy-d-mannose related to the cell wall polysaccharide of Rhizobium trifolii 4s has been achieved by a [2+3] approach from commercially available l-rhamnose, d-glucose, and d-glucosamine as the starting materials. The target molecule was equipped with a p-methoxylphenyl handle at the reducing terminus to allow for further glycoconjugate formation via selective cleavage of this group. The bioassay suggested that the synthetic pentasaccharide 2 can stimulate the growth of wheat coleoptile similarly to indole-3-acetic acid (IAA), and promote the wheat seedling development before winter by seed treatment at a concentration of 20mg/L.
3.Synthesis of β-D-fructofuranosyl-(2→1)-2-acetamido-2-deoxy-α-D-glucopyranoside (N-acetylsucrosamine) using β-fructofuranosidase-containing Aspergillus oryzae mycelia as a whole-cell catalyst.
Hirano T1, Wada T, Iwai S, Sato H, Noda M, Juami M, Nakamura M, Kumaki Y, Hakamata W, Nishio T. Carbohydr Res. 2012 May 15;353:27-32. doi: 10.1016/j.carres.2012.03.037. Epub 2012 Apr 5.
Using soft granules consisting of Celite 535 and dried Aspergillus oryzae NBRC100959 mycelia containing β-fructofuranosidase as a whole-cell catalyst, N-acetylsucrosamine [β-D-fructofuranosyl-(2→1)-2-acetamido-2-deoxy-α-D-glucopyranoside] was produced from sucrose and 2-acetamido-2-deoxy-D-glucose by enzymatic transfructosylation. The isolated yield of N-acetylsucrosamine from the reaction mixture was 22.1% (from sucrose). The result of N-terminal amino acid sequence analysis indicated that the enzyme involved in the synthesis of N-acetylsucrosamine is a product from gene (NCBI accession number; NW_001884675, locus tag; AOR_1_1114084) encoding putative β-fructofuranosidase on chromosome 6 of strain NBRC100959. The N-acetylsucrosamine we produced is highly soluble in water and is more stable in acidic solution than sucrose. The disaccharide was also produced using dried mycelia prepared from another A. oryzae strains.
4.One-pot enzymatic production of 2-acetamido-2-deoxy-D-galactose (GalNAc) from 2-acetamido-2-deoxy-D-glucose (GlcNAc).
Inoue K1, Nishimoto M, Kitaoka M. Carbohydr Res. 2011 Nov 8;346(15):2432-6. doi: 10.1016/j.carres.2011.08.032. Epub 2011 Sep 8.
2-Acetamido-2-deoxy-D-galactose (GalNAc) is a common monosaccharide found in biologically functional sugar chains, but its availability is often limited due to the lack of abundant natural sources. In order to produce GalNAc from abundantly available sugars, 2-acetamido-2-deoxy-D-glucose (GlcNAc) was converted to GalNAc by a one-pot reaction using three enzymes involved in the galacto-N-biose/lacto-N-biose I pathway of bifidobacteria. Starting the reaction with 600 mM GlcNAc, 170 mM GalNAc was produced at equilibrium in the presence of catalytic amounts of ATP and UDP-Glc under optimized conditions. GalNAc was separated from GlcNAc using water-eluting cation-exchange chromatography with a commonly available cation-exchange resin.