Full NMR assignment, revised structure and biosynthetic analysis for the capsular polysaccharide from Streptococcus Pneumoniae serotype 15F

Structure characterization of novel heteropolysaccharides from Pteridium revolutum with antioxidant and antiglycated activities

“…The signal at δ C 101.70 ppm was were attributed to the (1 → 6)-linked d - Gal p residue, the corresponding anomeric proton signal appeared at δ H 5.02 ppm, which affirmed the (1 → 6)-linked d -Gal p was α - d -conformation ( Cui et al, 2007 , Pramanik et al, 2005 ) ( Table 3 ). Similarly, the signals at δ H /δ C 5.39/98.65 and 4.82/101.88 ppm belonged to H1/C1 of (1 → 3)- and (1 → 3,6)-linked α- d -Gal p residues, respectively ( Jing et al, 2014 , Li et al, 2021 , Siwińska et al, 2020 ). The signals of H1/C1 at δ H /δ C 5.86/111.19, 5.86/110.78, 5.57/98.50, 5.22/100.55, 5.18/101.18, 5.17/101.34, 5.04/101.53, 5.00/102.64, 4.90/102.20, 4.88/102.43, 4.52/103.12, and 4.40/102.83 confirmed the presence of T- α- l -Ara f -(1→ ( Zhang et al, 2021a ), →5)- α- l -Ara f -(1→ ( Makarova and Shakhmatov, 2020 , Chen et al, 2019 ), →3,6)- α- d -Man p -(1→ ( Chen et al, 2019 , Roslund et al, 2011 ), →2)- α- d -Man p -(1→ ( Smiderle et al, 2013 , Naumenko et al, 2020 ), →4)- α- d -Xyl p -(1→ ( He et al, 2013 ), →2)- α- d -Xyl p -(1→ ( Makarova & Shakhmatov, 2021 ), T- α- d -Man p -(1→ ( Roslund et al, 2011 , Liu et al, 2021a ), →3)- α-L - Rha p -(1→ ( Bellich et al, 2021 ), T- α- d -Xyl p -(1→ ( Makarova & Shakhmatov, 2021 ), →3)- α-D -Fuc p -(1→ ( Liu et al, 2021b , Szpakowska et al, 2020 ), →6)- β- d -Glc p - (1→ ( Liu et al, 2021b , Li et al, 2020 ), and T- β- d -Glc p -(1→ residues ( Li et al, 2020 , Wang and Guo, 2020 ), respectively.…”

“…From the NMR spectra of PRP2 ( S-Fig. 11 ), ten anomeric H and C atoms appeared at δ H /δ C 5.88/110.82, 5.40/97.85, 5.17/101.99, 5.17/101.75, 5.06/101.39, 5.02/102.65, 5.01/101.09, 4.92/98.66, 4.89/101.86, and 4.39/102.43 ppm ( Table 3 ) were assigned to →5)- α- l -Ara f -(1→ ( Makarova and Shakhmatov, 2020 , Chen et al, 2019 ), →3)- α- d -Gal p -(1→ ( Jing et al, 2014 , Li et al, 2021 , Siwińska et al, 2020 ), →4)- α- d -Xyl p -(1→ ( He et al, 2013 ), →2)- α- d -Xyl p - (1→ ( Makarova, & Shakhmatov, 2021 ), →2,4)- α- d -Man p -(1→ ( Roslund et al, 2011 , Song et al, 2019 ), →3)- α- l -Rha p -(1→ ( Bellich et al, 2021 ), →6)- α- d -Gal p -(1→ ( Cui et al, 2007 , Pramanik et al, 2005 ), T- α- d -Gal p -(1→ ( Zhang et al, 2021b ), →3)- α- d -Fuc p -(1→ ( Liu et al, 2021b , Szpakowska et al, 2020 ), and T- β- d -Glc p -(1→ ( Li et al, 2020 , Wang and Guo, 2020 ), respectively. The signals in the upfield at δ H / δ C 1.15–1.25/16.5–18.5 ppm confirmed the presence of fucose and rhamnose.…”