Development of a Gemini Interfacial Antioxidant for Oil in Water Emulsion with Gallic Acid and Dodecyl Gemini Chains

Cyclometalated Half-Sandwich Ruthenium Complexes: Preparation, Structure, and Catalytic Synthesis of Phenolic Esters from Aryl Halides without Using External CO under Air

A series of cyclometalated C,N-chelate half-sandwich ruthenium complexes based on N-heterocyclic ligands were prepared through a simple route with good yields. These air- and moisture-stable cyclometalated ruthenium complexes showed excellent catalytic efficiency in phenoxy carbonylation of aryl halides with phenyl formate derivatives as a CO source and phenol as a coupling partner under air. Ester products were obtained with high yields at room temperature and without the need for an inert atmosphere. The excellent catalytic activity, broad substrate range, and mild reaction conditions made this catalytic system potential for industrial production. In addition, DFT study has been carried out to elaborate the possible mechanism of this Ru-catalyzed reaction.

Investigation of the structure of gallate xylose polymers and their antioxidant properties for skin care products

Xylose is the second most abundant monosaccharide in nature, and gallic acid (GA) has properties of antioxidant, anti-inflammatory and anti-bacterial. Hence, the gallate xylose (GX) polymers were synthesized from d-xylose and gallic acid for skin care applications in this paper. Then, the structure, generation mechanisms and the antioxidant activity of the generated polymer were studied. It got the results that: The generated GX polymers have strong antioxidant properties, yielded in 80.1% of GA mass. The DPPH scavenging activity was over 80.0% under the polymer's solution over 0.2 mg/mL. Moreover, the reaction mechanisms of DPPH removal were explained in a new theory based on Mass spectral analysis. Therefore, it demonstrates that the GX polymers of is a potential antioxidant material for skin care products, and it does contribution to the theory of DPPH removal for application in the fields of chemistry, biology and medicine researches.

Development of Galloyl Antioxidant for Dispersed and Bulk Oils through Incorporation of Branched Phytol Chain

In this study, a novel galloyl phytol antioxidant was developed by incorporating the branched phytol chain with gallic acid through mild Steglich esterification. The evaluation of the radical scavenging activity, lipid oxidation in a liposomal model, and glycerol trioleate revealed its superior antioxidant activities in both dispersed and bulk oils. Then, the antioxidant capacity enhancement of galloyl phytol was further explored using thermal gravimetry/differential thermal analysis (TG/DTA), transmission electron microscopy (TEM), and molecular modeling. The EC50 values of GP, GPa, and GE were 0.256, 0.262, and 0.263 mM, respectively, which exhibited comparable DPPH scavenging activities. These investigations unveiled that the branched aliphatic chain enforced the coiled molecular conformation and the unsaturated double bond in the phytol portion further fixed the coiled conformation, which contributed to a diminished aggregation tendency and enhanced antioxidant activities in dispersed and bulk oils. The remarkable antioxidant performance of galloyl phytol suggested intriguing and non-toxic natural antioxidant applications in the food industry, such as effectively inhibiting the oxidation of oil and improvement of the quality and shelf life of the oil, which would contribute to the use of tea resources and extending the tea industry chain.

Progress in the Application of Food-Grade Emulsions

The detailed investigation of food-grade emulsions, which possess considerable structural and functional advantages, remains ongoing to enhance our understanding of these dispersion systems and to expand their application scope. This work reviews the applications of food-grade emulsions on the dispersed phase, interface structure, and macroscopic scales; further, it discusses the corresponding factors of influence, the selection and design of food dispersion systems, and the expansion of their application scope. Specifically, applications on the dispersed-phase scale mainly include delivery by soft matter carriers and auxiliary extraction/separation, while applications on the scale of the interface structure involve biphasic systems for enzymatic catalysis and systems that can influence substance digestion/absorption, washing, and disinfection. Future research on these scales should therefore focus on surface-active substances, real interface structure compositions, and the design of interface layers with antioxidant properties. By contrast, applications on the macroscopic scale mainly include the design of soft materials for structured food, in addition to various material applications and other emerging uses. In this case, future research should focus on the interactions between emulsion systems and food ingredients, the effects of food process engineering, safety, nutrition, and metabolism. Considering the ongoing research in this field, we believe that this review will be useful for researchers aiming to explore the applications of food-grade emulsions.

Gallic Acid and Diabetes Mellitus: Its Association with Oxidative Stress

Diabetes mellitus (DM) is a severe chronic metabolic disease with increased mortality and morbidity. The pathological progression of DM is intimately connected with the formation and activation of oxidative stress (OS). Especially, the involvement of OS with hyperglycemia, insulin resistance, and inflammation has shown a vital role in the pathophysiological development of DM and related complications. Interestingly, accumulating studies have focused on the exploration of natural antioxidants for their improvement on DM. Of specific interest is gallic acid (GA), which is rich in many edible and herbal plants and has progressively demonstrated robust antioxidative and anti-inflammatory effects on metabolic disorders. To provide a better understanding of its potential therapeutic impacts and enhancement of human health care, the available research evidence supporting the effective antidiabetic properties of GA and relevant derivatives are needed to be summarized and discussed, with emphasis on its regulation on OS and inflammation against DM. This review aims to highlight the latest viewpoints and current research information on the role of OS in diabetes and to provide scientific support for GA as a potential antihypoglycemic agent for DM and its complications.

Rapid Cu(II)-Directed Self Assembly of Esterified Tea Polyphenol Oligomers to Controlled Release Nanoflower Carrier

In this study, novel tea polyphenolic-copper hybrid nanoflowers were assembled with tea polyphenol palmitate oligomers generated simply through air oxidation. It was revealed that the growth of tea polyphenolic-based hybrid nanoflowers was notably faster than protein-based ones, presumably owing to rigid polyphenolic molecular architecture and the resultant different growth mechanism. The structures and composition investigation by FT-IR, X-ray, and SEM-EDS unveiled that the whole framework of the nanoflowers was composed of complexes of tea polyphenolic oligomers and copper phosphate crystals. The tea polyphenolic hybrid nanoflowers demonstrated high loading capacity of curcumin due to flower-like porous structure and hydrophobic pockets furnished by lipophilic side chains. The nanoflowers exhibited remarkable protection capacity for carried curcumin from UV irradiation and thermal treatment. Controlled release of the nanoflowers could be readily achieved by adjustment of pH condition. Owing to high assembly efficiency, biocompatibility, and natural abundance, tea polyphenols are intriguing organic components to generate nanoflowers.