ABSTRACT
This study attempts to reveal antioxidants in the plant parts of Myxopyrum smilacifolium (Wall.) Blume using antioxidant assays and LC-MS/MS analysis. Methanol is the most effective solvent for collecting antioxidants. The roots-derived methanol extract demonstrates the greatest antioxidant activity, corresponding to the extremely low IC50 values of 16.39 µg/mL and 19.80 µg/mL for DPPH and ABTS radicals, respectively. The high phenolic and flavonoid contents are the primary reason for outstanding total antioxidant capacity (TAC; i.e. 247.73 ± 1.62 mg GA/g or 163.93 ± 0.83 mg AS/g) of the root extract. LC-MS/MS quantification of five phenolic compounds reveals exceptionally high amounts of quercetin and luteolin in the root extract, ranging from 238.86 ± 5.74 to 310.99 ± 1.44 µg/g and from 201.49 ± 7.84 to 234.10 ± 2.54 µg/g, respectively, in the root-derived methanol extract. The achievement highlights M. smilacifolium as a promising source of natural antioxidants for large-scale medical applications.
ABSTRACT
Exploring structural biomimicry is a great opportunity to replicate hierarchical frameworks inspired by nature in advanced functional materials for boosting new applications. In this work, we present the biomimetic integration of polythiophene into chitosan nanofibrils in a twisted Bouligand structure to afford free-standing macroscopic composite membranes with electrochemical functionality. By considering the integrity of the Bouligand structure in crab shells, we can produce large, free-standing chitosan nanofibril membranes with iridescent colors and flexible toughness. These unique structured features lead the chitosan membranes to host functional additives to mimic hierarchically layered composites. We used the iridescent chitosan nanofibrils as a photonic platform to investigate the host-guest combination between thiophene and chitosan through oxidative polymerization to fabricate homogeneous polythiophene-wrapped chitosan composites. This biomimetic incorporation fully retains the twisted Bouligand organization of nanofibrils in the polymerized assemblies, thus giving rise to free-standing macroscopic electrochemical membranes. Our further experiments are the modification of the biomimetic polythiophene-wrapped chitosan composites on a glassy carbon electrode to design a three-electrode system for simultaneous electrochemical detection of uric acid, xanthine, hypoxanthine, and caffeine at trace concentrations.
ABSTRACT
The presented study attempts to unveil and evaluate the antioxidant activity of a novel heteropolysaccharide separated from the roots of Myxopyrum smilacifolium (denoted as PS-MSR). The molecular weight of PS-MSR is found to be 1.88 × 104 Da and contains two principal sugars, which are d-glucose and d-fructose, in the backbone. Decoding the structure of the obtained PS-MSR sample has disclosed a novel polysaccharide for the first time. Indeed, the PS-MSR is composed of (1 â 3)-linked glucosyl units and (2 â 3)-linked fructosyl units. In addition, the 1D and 2D NMR spectra of the PS-MSR sample display the repeating unit of the isolated polysaccharide, [â3)-α-d-Glcp-(1 â 3)-ß-d-Frucf-(2 â 3)-ß-d-Frucf-2 â 3)-)-ß-d-Frucf-ß-(2â] n . Interestingly, the PS-MSR sample exhibits outstanding antioxidant activity, signifying the potential utilization of the explored polysaccharide for antioxidant-based material.
ABSTRACT
The increasing incidence of resistance in tuberculosis and in atypical mycobacterial infections has prompted the search for alternative agents. We explored the antimycobacterial activity of Melaleuca cajuputi essential oil against tubercular and non tubercular mycobacterials isolates. The good activity observed towards M. cajuputi indicated that this essential oil might represent a promising antimicrobial agents, particularly in the management of microbial resistance.