Search

In this work, a novel antibacterial mesoporous material containing N-halamine was prepared. The N-halamine precursor monomer, 3-(3′-hydroxypropyl)-5,5-dimethylhydantoin (APDMH), was synthesized. After modification with siloxane agents, the precursor monomer was polymerized onto the surface of mesoporous materials (SBA-15). The initial and modified samples were characterized by SEM, TEM, FT-IR, TG, XRD, small-angle X-ray scattering diffraction, and BET analyses. The results showed that the N-halamine precursor was successfully grafted onto the surface of the mesoporous materials and that the morphology was affected slightly. The surface area of SBA-15 did not change significantly after modification. After being treated with commercial sodium hypochlorite solution, the modified material became antibacterial. The polymeric N-halamine mesoporous material exhibited excellent antibacterial activity and could inactivate 6.70 and 7.00 logs of Staphylococcus aureus (ATCC 6538) and E. coli O157:H7 (ATCC 43895), respectively, within 5 min of contact. The N-halamine-modified mesoporous material with potent antibacterial efficacy has potential in the application of water treatment and biomaterial areas. [ABSTRACT FROM AUTHOR]

Citri Reticulatae Pericarpium (CRP) is one of the most commonly used food supplements and folk medicines worldwide, and possesses cardiovascular, digestive, and respiratory protective effects partially through its antioxidant and anti-inflammatory functions. The unique aromatic flavor and mild side effects make CRP a promising candidate for the development of anti-inflammatory functional food. However, recent studies show that the crude alcoholic extract and some isolated compounds of CRP show compromised anti-inflammatory activity, which became the main factor hindering its further development. To identify the bioactive compounds with anti-inflammatory potential, and improve the anti-inflammatory effects of the extract, a bioinformatics-guided extraction protocol was employed in this study. The potential bioactive candidates were identified by combing network pharmacology analysis, molecular docking, principal components analysis, k-means clustering, and in vitro testing of reference compounds. Our results demonstrated that 66 compounds in CRP could be grouped into four clusters according to their docking score profile against 24 receptors, while the cluster containing flavonoids and phenols might possess a more promising anti-inflammatory function. In addition, in vitro anti-inflammatory tests of the seven reference compounds demonstrated that hesperitin, naringenin, and gardenin B, which were grouped into a cluster containing flavonoids and phenols, significantly decreased LPS-induced NO, TNF-α, and IL-6 production of macrophages. While the compounds outside of that cluster, such as neohesperidin, naringin, hesperidin, and sinensetin showed little effect on alleviating LPS-induced NO and proinflammatory cytokine production. Based on the chemical properties of selected compounds, ethyl acetate (EtOAc) was selected as the solvent for extraction, because of its promising solubility of flavonoids and phenols. Furthermore, the ethanol alcoholic extract was used as a reference. The chemical profiling of EtOAc and crude alcoholic extract by HPLC/MS/MS also demonstrated the decreased abundance of flavonoid glycosides in EtOAc extract but increased abundance of phenols, phenolic acid, and aglycones. In accordance with the prediction, the EtOAc extract of CRP, but not the crude alcoholic extract, significantly decreased the NO, IL-6, and TNF-α production. Taken together, the results suggested selective extraction of phenols and flavonoids rich extract was able to increase the anti-inflammatory potential of CRP partially because of the synergistic effects between flavonoids, phenols, and enriched polymethoxyflavones. Our study might pave the road for the development of ethyl acetate extract of CRP as a novel functional food with anti-inflammatory function. [ABSTRACT FROM AUTHOR]

The pericarp of Citrus reticulata cv. Chachiensis (PCRC) had been used as a traditional herbal medicine in southeast and eastern Asia, and it was also an important source of nutraceuticals and functional food ingredients. In the present study, the cell wall polysaccharides were sequentially extracted from PCRC using different solvents, resulting in five pectic fractions and two hemicellulose fractions, namely water-soluble pectin (WSP), hot water-soluble pectin (HWSP), chelator-soluble pectin (CSP), diluted acid-soluble pectin (HSP), sodium carbonate-soluble pectin (NSP), 1 mol/L KOH soluble hemicellulose (KSH-1) and 4 mol/L KOH soluble hemicellulose (KSH-2). The seven fractions were characterized in terms of composition, structure, thermal, rheological, and antioxidant properties. The pectin fractions were classified as high-methoxy pectin with a degree of methyl esterification (DM) between 56.89% and 62.20%. Ammonium oxalate extraction provided the CSP fraction with the highest content of galacturonic acid (75.18%) and the lowest degree of acetylation (0.03). HWSP was considered to be an aggregative of homogalacturonan (HG) and rhamnogalacturonan I (RG-I) containing side chains of galactans and arabinans. Thermal analysis indicated that HWSP had the highest thermal stability than other fractions. All fractions exhibited the characteristics of non-Newtonian fluids, with NSP showing the highest apparent viscosity. Assays for antioxidant activities suggested WSP had the highest DPPH radical scavenging activity while NSP had the highest hydroxyl radical scavenging activity. The result could be a good basis for the applications of cell wall polysaccharides, especially pectin, of PCRC in the preparation of functional food products. [Display omitted] • The total content of high methoxyl pectin up to 36.81% was obtained from the pericarp of Citrus Reticulata cv. Chachiensis. • Chelator-soluble pectin with GalA content up to 75.18% was expected to be a source of commercial pectin. • Hot water-soluble pectin was shown to consist of HG and RG-I backbones containing side chains of galactans and arabinans. • Water-soluble pectin showed the higher thermal stability and DPPH radical scavenging activity. • Sodium carbonate-soluble pectin exhibited the highest apparent viscosity and hydroxyl radical scavenging activity. [ABSTRACT FROM AUTHOR]

• A novel porous antimicrobial starch particle containing N-Halamine functional groups was prepared. • N-Halamine functional groups of PST-MBA-Cl particles also showed excellent stability under storage and reproducibility. • The Cl+ content reached 8.60 % under optimum synthesis condition. PST-MBA-Cl particles could kill all of S. aureus and E. coli within 1 min. The porous antimicrobial starch particles containing N-Halamine functional groups (PST-MBA-Cl particles) were synthesized by a crosslinking polymerization between starch (ST) and N, N' -methylenebisacrylamide (MBA), and then a chlorination of amide groups of MBA. The synthetic process used only water as the solvent and was environmentally friendly. The results showed that under the optimal preparation conditions, the as-synthesized PST-MBA-Cl particles could have a Cl+% of 8.60 %. Antimicrobial tests showed that PST-MBA-Cl particles had very powerful antimicrobial efficacy against both Staphylococcus aureus and Escherichia coli and could completely kill Staphylococcus aureus with a concentration of 2.1 × 106 CFU/mL and Escherichia coli with a concentration of 5.6 × 106 CFU/mL within a contact time of one minute. Furthermore, the N-Halamine functional groups of PST-MBA-Cl particles also showed excellent stability under storage and reproducibility. Therefore, the as-synthesized PST-MBA-Cl particles will have potential applications in water disinfection. [ABSTRACT FROM AUTHOR]