Identification of bioactive polysaccharide from Pseudostellaria heterophylla with its anti-inflammatory effects

Pseudosterins A–C, Three 1-Ethyl-3-formyl-β-carbolines from Pseudostellaria heterophylla and Their Cardioprotective Effects

“…The IR absorptions suggested the presence of hydroxy or/and amino (3443-3210 cm −1 ), -NH2 (1649 and 1562 cm −1 ), and aromatic (1625 and 1508 cm −1 ) groups (see Figure S29). The 1 H-NMR data (see Table1 and Figure S30) of 3 was very close to those of 2 in DMSO-d6 (due to poor coupling splitting in pyridine-d5, 3 was detected in DMSO-d6); these observations suggested that compound 3 also possessed a similar 11-β-glucopyranosyl-βcarboline structure, which was also supported by a UV, 13 C NMR, 1 H-1 H COSY, HSQC, and HMBC correlation (see Figure 2 and Figures S28, S31-S35). HMBC correlation between -NH2 (δH 7.98, 1H, d, J = 2 Hz; δH 7.45, 1H, d, J = 2 Hz) and C-10 (δC 166.9), as well as the IR analysis (1643 and 1562 cm −1 ), indicated the presence of a CO-NH2 group at C-10.…”

“…The IR absorptions suggested the presence of hydroxy or/and amino (3443-3210 cm −1 ), -NH 2 (1649 and 1562 cm −1 ), and aromatic (1625 and 1508 cm −1 ) groups (see FigureS29). The 1 H-NMR data (see Table1and FigureS30) of 3 was very close to those of 2 in DMSO-d 6 (due to poor coupling splitting in pyridine-d 5 , 3 was detected in DMSO-d 6 ); these observations suggested that compound 3 also possessed a similar 11-βglucopyranosyl-β-carboline structure, which was also supported by a UV,13 C NMR, 1 H-1 H…”

“…Its UV and IR spectra (see Figures S19 and S20) bore a resemblance to those of 1, indicating the presence of similar functionalities. Except signals for the glutamic acid moiety, the 13 C-NMR data of 2 are very close to those of 1 (see Table 1 and Figures S22-S23), suggesting a possible β-carboline skeleton and a hexose moiety for 2. However, the poor solubility of 2 in CD 3 OD gave poor peak resolution, which retarded the full assignments of the NMR data, whereas 1 H-NMR data recorded in pyridine-d 5 are well-resolved and the structure was established by detailed 2D NMR ( 1 H-1 H COSY, HSQC, and HMBC) data analysis (see Figures S21, S24-S26).…”

“…3000-2500 cm −1 ), carbonyl (1718 cm −1 ), and aromatic (1594 and 1498 cm −1 ) functionalities (see Figure S5 and Table S4). In the 1 H-NMR spectrum data of 1 (CD 3 OD, see Table 1 13 C-NMR data with those of 1-methyl-β-carboline-3-yl-(piperidin-1-yl)methanone [24], ethyl 2-methyl-9H-pyrido [2,3-b]indole-3-carboxylate [25] and flazin [26], and taking into consideration the elemental constitution and carbon resonances, a β-carboline scaffold was supposed to be present in 1 through convergence of the 1,2-disubstituted benzene group (see Figure S4), two of the three nitrogen atoms, and the five non-acyl sp 2 carbons. Two-dimensional NMR experiments (HSQC, 1 H-1 H COSY, and HMBC) were further carried out to confirm the conclusion and to reveal the details of the structure.…”

“…Optical rotations were measured on a Perkin-Elmer 341 polarimeter (PerkinElmer, Boston, MA, USA). NMR spectra were recorded on a Bruker AVANCE NEO 600 M ( 1 H: 600 MHz; 13 C: 150 MHz) (Bruker, Karlsruhe, Germany) or JEOL ECX 500/400 NMR spectrometer ( 1 H: 500/400 MHz; 13 C: 125/100 MHz) (JEOL, Akishima-shi, Japan). Thin-layer chromatography (TLC) was executed on silica gel GF 254 from Qingdao Haiyang Chemical Co., Ltd, Qingdao, China (QHCC), detected under a UV lamp at 254 or 365 nm, and visualized by spraying with 10% sulfuric acid/ethanol (v/v) solution followed by heating.…”