New Glycosides from the Fruits of Nicandra physaloides

Eight undescribed steroidal saponins including an unprecedented 16, 26-epoxy-furostanol saponin from Solanum xanthocarpum and their cytotoxic activities

Eight undescribed steroidal saponins named solasaponins A-H were isolated from the fruits of Solanum xanthocarpum, including an unusual 16,26-epoxy-furostanol saponin, two furostanol saponins, three isospirostanol saponins, two pseudo-spirostanol saponins. The structures of all compounds were elucidated by extensive spectroscopic data analyses (1D, 2D NMR, and HRESIMS) combined with physico-chemical analysis methods (acid hydrolysis, optical rotation, and IR). The cytotoxicities of all compounds in vitro against two human cancer cell lines (A-549 and HepG2) were evaluated by CCK-8 assay.

Rheological and gelling properties of Nicandra physalodes (Linn.) Gaertn. pectin in acidic media

Nicandra physalodes (Linn.) Gaertn. polysaccharide (NPGP) was previously recognized as a pectic polysaccharide, with a high galacturonic acid content (87.8%) and a low methoxylation degree (28%). In the present study, it was found that NPGP can form self-supporting gels when cooling its heated solutions (2.0%, w/v) acidified by citric acid. It was demonstrated that the decrease in pH led to the suppression in electrostatic repulsions between the pectin chains, thereby promoting pectin chain-chain association mainly through hydrogen bonding. As the pH decreased from 3.2 to 2.4, the gel strength and gel thermal stability were continuously increased. Moreover, it was shown that sucrose addition slightly promoted the gelation and gel thermal stability of NPGP, but the effect of monovalent ions (Na⁺) and divalent ions (Ca²⁺) was not significant. Conclusively, our results indicate that NPGP is a new gelling polysaccharide that shows great potential in formulation of acidic gel foods.

A Natural Polymer Captor for Immobilizing Polysulfide/Polyselenide in Working Li-SeS2 Batteries

SeS₂ has become a promising cathode material owing to its enhanced electrical conductivity over sulfur and higher theoretical specific capacity than selenium; however, the working Li-SeS₂ batteries have to face the practical challenges from the severe shuttling of soluble dual intermediates of polysulfide and polyselenide, especially in high-SeS₂-loading cathodes. Herein, a natural organic polymer, Nicandra physaloides pectin (NPP), is proposed to serve as an effective polysulfide/polyselenide captor to address the shuttling issues. Informed by theoretical calculations, NPP is competent to provide a Lewis base-based strong binding interaction with polysulfides/polyselenides via forming lithium bonds, and it can be homogeneously deposited onto a three-dimensional double-carbon conductive scaffold to finally constitute a polysulfide/polyselenide-immobilizing interlayer. Operando spectroscopy analysis validates the enhanced polysulfide/polyselenide trapping and high conversion efficiency on the constructed interlayer, hence bestowing the Li-SeS₂ cells with ultrahigh rate capability (448 mAh g^-1 at 10 A g^-1), durable cycling lifespan (≈ 0.037% capacity attenuation rate per cycle), and high areal capacity (> 6.5 mAh cm^-2) at high SeS₂ loading of 15.4 mg cm^-2. Importantly, pouch cells assembled with this interlayer exhibit excellent flexibility, decent rate capability with relatively low electrolyte-to-capacity ratio, and stable cycling life even under a low electrolyte condition, promising a low-cost, viable design protocol toward practical Li-SeS₂ batteries.