New metal complexes of citrus pectin with magnesium ions: synthesis, properties, and immunomodulatory activity

Cobalt polygalacturonates and the pharmacological composition based on them: Preparation, properties and cytotoxicity

The aim of the present study was to obtain new metal complexes of citrus pectin with cobalt ions based on potassium polygalacturonate and to prepare a new pharmacological composition (PC) PGKCo: PGNaCo (1:1) with antitumor activity based on potassium cobalt polygalacturonate (PGKCo) and sodium cobalt polygalacturonate (PGNaCo). The study of the effect of PGKCo, PGNaCo and PC on the cell viability of tumor cell lines of different genesis in vitro showed that the obtained compounds are soluble in water and exhibit selective cytotoxic activity against the tumor cell lines of human lung carcinoma A549, breast adenocarcinoma MCF-7 and cervical carcinoma M-HeLa, with no significant toxic effect on normal human cells. The possible mechanism of action of the investigated PC on M-HeLa cancer cells was investigated. The mechanism of action of PC was found to be associated with cell cycle arrest in the G0/G1 phase and the induction of apoptosis through the mitochondrial pathway. The results obtained indicate the potential for the non-toxic compounds (PGKCo, PGNaCo and PC) to be developed as drugs for the complex treatment of oncologic diseases.

Effect of metal cation crosslinking on the mechanical properties and shrimp freshness monitoring sensitivity of pectin/carboxymethyl cellulose sodium/anthocyanin intelligent films

Although many preparation methods have been reported so far, it is still a great challenge for intelligent packaging films with both excellent mechanical properties and very high sensitivity. Herein, we report a facile method to prepare performance-enhanced pectin (PC)/carboxymethyl cellulose sodium (CMC)/anthocyanins (ACNs)/metal ion films by crosslinking with metal ions (Zn2+, Mg2+ and Ca2+). Cross-linking reaction between PC/CMC and metal ions significantly improved water resistance and mechanical properties of composite films (P < 0.05). Even at high relative humidity (RH = 84 %), cross-linking of Ca2+, Mg2+, and Zn2+ significantly increased the tensile index of the films by 1.37, 1.41, and 1.52 times (P < 0.05), respectively. Moreover, the complexation of metal ions/polysaccharides with ACNs reduced the decomposition rate of ACNs, improved the storage stability and antioxidant capacity of ACNs, and also increased the sensitivity of the colorimetric response of the indicator films in monitoring shrimp freshness. Thus, with this high sensitivity, the Red, Green and Blue (RGB) values of the films can be determined using a mobile phone application to monitor shrimp safety in real time. These results suggest that ACNs-metal cation-polysaccharide composite films have great potential for smart packaging applications.

Physicochemical, structural and functional properties of low methoxyl pectin‑iron (III) complex and its effect on rats with iron deficiency anemia

Iron deficiency anemia (IDA) is the most common nutritional disease worldwide. In this study, a low methoxyl pectin (LMP)‑iron(III) complex was prepared. The physicochemical and structural properties were characterized by HPSEC, HPIC, CV, FTIR, 1H NMR, XRD, SEM and CD. The results showed that iron increased the molecular weight of the LMP‑iron(III) from 11.50 ± 0.32 to 12.70 ± 0.45 kDa and improved its crystallinity. Moreover, the findings demonstrated that -OH and -COOH groups in LMP coordinate with Fe3+ to form β-FeOOH. The water-holding capacity, emulsion stability, and antioxidant activities of the LMP‑iron(III) were lower than those of LMP. Furthermore, the therapeutic effects of LMP‑iron(III) on IDA were investigated in rats. Following LMP‑iron(III) supplementation, compared with the model group, the administration of LMP‑iron(III) significantly increased the body weight, hemoglobin concentration, and serum iron concentration as well as decreased free erythrocyte protoporphyrin concentration. Therefore, the LMP‑iron(III) can potentially treat IDA in rats experiments, providing a theoretical basis for the development of a promising iron supplement.