Effect of dandelion root polysaccharide on the pasting, gelatinization, rheology, structural properties and in vitro digestibility of corn starch.

The influence of dandelion root polysaccharide (DRP) on the gelatinization properties and in vitro digestibility of corn starch was investigated. Pasting behaviors indicated that the addition of DRP led to an increase of the pasting temperature and a decrease of viscosity. Compared to native corn starch, the swelling power, solubility and content of amylose leaching were reduced as the DRP addition increased. Scanning electron microscopy (SEM) analysis showed that DRP was easily dispersed in the starchy matrix, and a more uniform structure was observed in corn starch/DRP pastes. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analyses confirmed that the crystal shape of the corn starch gels was not changed and no new groups were produced with increasing DRP concentration. Moreover, DRP could improve the fluidity of the gelatinized corn starch and reduce its digestibility. These findings provided fundamental information about DRP's application in the whole processing of corn starch.

Characterization, antioxidant and immunomodulatory effects of selenized polysaccharides from dandelion roots.

The polysaccharide (DRP) was gained from dandelion roots by ultrasonic-assisted enzymatic extraction (UAEE) followed by two-step column purification. Then selenylation of DRP has been accomplished by HNO3-Na2SeO3 method. sDRP-1 and sDRP-2 with the selenium content of 170 ± 1.13 and 710 ± 4.00 µg/g were prepared for further structural characterization and bioactivity determination. DRP, sDRP-1, and sDRP-2 were composed of the same monosaccharides in different molar ratios, and the molecular weights of DRP, sDRP-1 and sDRP-2 were 8700, 7900, and 5600 Da, respectively. Fourier transform infrared (FT-IR) spectra confirmed that DRP, sDRP-1, and sDRP-2 possessed similar functional groups. The results of Congo red test, X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that DRP, sDRP-1, and sDRP-2 had no three helix structure, did not form single crystal, and all belonged to amorphous morphology. sDRP-1 and sDRP-2 possessed greater antioxidant activities in vitro than the native polysaccharide DRP. At the same time, the selenized polysaccharides showed better immunomodulatory ability and could be used as new-type immunoenhancer. The present conclusions provided theoretical basis for the new application of dandelion polysaccharides and the development of dandelion resources.

New Triterpenoid Saponins from the Herb Hylomecon japonica.

Background: Hylomecon japonica, a plant of the Papaveraceae family which is well-known for the alkaloids they produce, is a perennial plant widely distributed in the northeast, central and east regions of China. Although a variety of chemical constituents, including alkaloids, flavonoids, and megastigmoids, have been isolated from H. japonica, the investigation of saponins in H. japonica has not been reported until now. Methods: Various separation techniques, including polyporous resin column chromatography, silica gel column chromatography and hemi-preparative HPLC were applied to the isolation of triterpenoid saponins, and chemical methods such as acid hydrolysis and spectroscopic methods including HRESIMS and NMR were applied to their structure elucidation, and the XTT reduction method was used to assay cytotoxicity. Results: Two new triterpenoid saponins, named hylomeconoside A (1) and B (2) which were identified as 3-O-ß-d-galactopyranosyl-(1→2)-ß-d-glucuronopyranosyl-gypsogenin-28-O-ß-d-xylopyranosyl-(1→3)-ß-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-ß-d-quinovopyranoside (1) and 3-O-ß-d-galactopyranosyl-(1→2)-ß-d-glucuronopyranosyl-gypsogenin-28-O-ß-d-xylopyranosyl-(1→3)-ß-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside (2), and two known triterpenoid saponins identified as dubioside C (3) and lucyoside P (4) on the basis of spectroscopic and chemical evidence, were isolated from H. japonica. Compound 1 exhibited moderate cytotoxicity on MGC-803 and HL-60 cells, with IC50 values of 43.8 and 32.4 µg·mL-1, respectively. Conclusions: Compounds 1 and 2 are new saponins, and 1 is considered to be one of the antitumor principles in this plant. This is the first time that triterpenoid saponins have been isolated from plants of the Papaveraceae family.