Microwave-assisted extraction of mucilage from juá: Characterization and antioxidant activity.

Microwave-assisted extraction of mucilage from juá was investigated using response surface methodology. The optimal conditions for extraction were a power of 300 W, an extraction time of 240 s, a pH of 8.0, and a water/sample ratio of 1/6, which achieved a 26.43% yield. The monosaccharide composition and antioxidant activity of the mucilage from juá fruits from different regions of Caatinga were investigated. The fruits from Agreste Paraibano showed the highest mucilage extraction yield (18.64%) compared to that of fruits from Mata Paraibana (MP) (12.37%), Borborema (BB) (11.47%), and Sertão Paraibano (8.31%) (p < 0.05). Glucose (32.8%-50.8%) and arabinose (19.3%-32.9%) were the main monosaccharides found in juá mucilage. The mucilage from fruits in the MP presented the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl and oxygen radical absorbance capacity assays. Our results demonstrated the potential for the future exploration and application of juá mucilage in the food industry. PRACTICAL APPLICATION: Juá (Ziziphus joazeiro Mart.) mucilage contains phenolic compounds and antioxidant activity, and its extraction by MAE is efficient, as it contributed to a higher yield.

Quality Evaluation of Lonicerae Flos Produced in Southwest China Based on HPLC Analysis and Antioxidant Activity.

Lonicera macranthoides, the main source of traditional Chinese medicine Lonicerae Flos, is extensively cultivated in Southwest China. However, the quality of L. macranthoides produced in this region significantly varies due to its wide distribution and various cultivation breeds. Herein, 50 Lonicerae Flos samples derived from different breeds of L. macranthoides cultivated in Southwest China were collected for quality evaluation. Six organic acids and three saponin compounds were quantitatively analyzed using HPLC. Furthermore, the antioxidant activity of a portion of samples was conducted with 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging experiments. According to the quantitative results, all samples met the quality standards outlined in the Chinese Pharmacopoeia. The samples from Guizhou, whether derived from unopened or open wild-type breeds, exhibited high quality, while the wild-type samples showed relatively significant fluctuation in quality. The samples from Chongqing and Hunan demonstrated similar quality, whereas those from Sichuan exhibited relatively lower quality. These samples demonstrated significant abilities in clearing ABTS and DPPH radicals. The relationship between HPLC chromatograms and antioxidant activity, as elucidated by multivariate analysis, indicated that chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C are active components and can serve as Q-markers for quality evaluation.

Synthesis and Antioxidant Activity of N-Benzyl-2-[4-(aryl)-1H-1,2,3-triazol-1-yl]ethan-1-imine Oxides.

The synthesis, antioxidant capacity, and anti-inflammatory activity of four novel N-benzyl-2-[4-(aryl)-1H-1,2,3-triazol-1-yl]ethan-1-imine oxides 10a-d are reported herein. The nitrones 10a-d were tested for their antioxidant properties and their ability to inhibit soybean lipoxygenase (LOX). Four diverse antioxidant tests were used for in vitro antioxidant assays, namely, interaction with the stable free radical DPPH (1,1-diphenyl-2-picrylhydrazyl radical) as well as with the water-soluble azo compound AAPH (2,2'-azobis(2-amidinopropane) dihydrochloride), competition with DMSO for hydroxyl radicals, and the scavenging of cationic radical ABTS•+ (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation). Nitrones 10b, 10c, and 10d, having the 4-fluorophenyl, 2,4-difluorophenyl, and 4-fluoro-3-methylphenyl motif, respectively, exhibited high interaction with DPPH (64.5-81% after 20 min; 79-96% after 60 min), whereas nitrone 10a with unfunctionalized phenyl group showed the lowest inhibitory potency (57% after 20 min, 78% after 60 min). Nitrones 10a and 10d, decorated with phenyl and 4-fluoro-3-methylphenyl motif, respectively, appeared the most potent inhibitors of lipid peroxidation. The results obtained from radical cation ABTS•+ were not significant, since all tested compounds 10a-d showed negligible activity (8-46%), much lower than Trolox (91%). Nitrone 10c, bearing the 2,4-difluorophenyl motif, was found to be the most potent LOX inhibitor (IC50 = 10 µM).

Antioxidant potentials of extracts from different parts of Clinacanthus nutans (Burm. f.) Lindau.

The research aimed to explore the antioxidant potential of extracts from different parts of Clinacanthus nutans growing in Vietnam, a member of the Acanthaceae family. The plant's roots, stem and leaves were extracted using 96% ethanol. The antioxidant actions of these extracts were evaluated by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay on thin-layer plates and 96 well plates. The extract with the most potent activity was applied for distribution extraction with solvents with different polarities, including dichloromethane, ethyl acetate and water. Dry column vacuum chromatography was utilized to obtain the most antioxidant-potent extract fractions. The stem extract had the lowest IC50 value of 6.85µg/mL, showing the most potent antioxidant activity. The ethyl acetate fraction from the stem extract expressed the lowest IC50 value of 9.67µg/mL. Meanwhile, fraction 5, separated from the ethyl acetate fraction of the stem extract, had the lowest IC50 value of 9.89µg/mL. In conclusion, the extracts from different parts of Clinacanthus nutans all expressed antioxidant action at different levels, in which the stem extract, the ethyl acetate fraction and fraction 5 from the ethyl acetate fraction displayed the most effective actions. These findings highlight the promising potential of Clinacanthus nutans in treating oxidative stress-associated diseases, inspiring further research and exploration in this area.

Identification of Novel Peptides in Distillers' Grains as Antioxidants, α-Glucosidase Inhibitors, and Insulin Sensitizers: In Silico and In Vitro Evaluation.

Distillers' grains are rich in protein and constitute a high-quality source of various bioactive peptides. The purpose of this study is to identify novel bioactive peptides with α-glucosidase inhibitory, antioxidant, and insulin resistance-ameliorating effects from distiller's grains protein hydrolysate. Three novel peptides (YPLPR, AFEPLR, and NDPF) showed good potential bioactivities, and the YPLPR peptide had the strongest bioactivities, whose IC50 values towards α-glucosidase inhibition, radical scavenging rates of 2,2'-azino-bis (3-ethylbenzothiazoline-6- sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were about 5.31 mmol/L, 6.05 mmol/L, and 7.94 mmol/L, respectively. The glucose consumption of HepG2 cells treated with YPLPR increased significantly under insulin resistance condition. Moreover, the YPLPR peptide also had a good scavenging effect on intracellular reactive oxygen species (ROS) induced by H2O2 (the relative contents: 102.35% vs. 100%). Molecular docking results showed that these peptides could stably combine with α-glucosidase, ABTS, and DPPH free radicals, as well as related targets of the insulin signaling pathway through hydrogen bonding and van der Waals forces. This research presents a potentially valuable natural resource for reducing oxidative stress damage and regulating blood glucose in diabetes, thereby increasing the usage of distillers' grains peptides and boosting their economic worth.

Extraction of Antioxidants from Brown Macroalgae Fucus spiralis.

In this study, different extraction methods and conditions were used for the extraction of antioxidants from brown macroalgae Fucus spiralis. The extraction methodologies used were ultrasound-assisted extraction (ultrasonic bath and ultrasonic probe), extraction with a vortex, extraction with an Ultra-Turrax® homogenizer, and high-pressure-assisted extraction. The extracts were analyzed for their total phenolic content (TPC) and their antioxidant activity, and evaluated through the 2,2-difenil-1-picrilhidrazil (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay. Ultrasonic probe-assisted extraction yielded the highest values of TPC (94.78-474.16 mg gallic acid equivalents/g extract). Regarding the antioxidant activity, vortex-assisted extraction gave the best DPPH results (IC50 1.89-16 µg/mL), while the highest FRAP results were obtained using the Ultra-Turrax® homogenizer (502.16-1188.81 µmol ascorbic acid equivalents/g extract). For each extraction method, response surface methodology was used to analyze the influence of the experimental conditions "extraction time" (t), "biomass/solvent ratio" (R), "solvent" (S, water % in water/ethanol mixture), and "pressure" (P) on TPC, DPPH, and FRAP of the F. spiralis extracts. In general, higher TPC content and higher antioxidant capacity (lower IC50 and higher FRAP) were obtained with higher R, t, and P, and lower S (higher ethanol %). The model regarding the combined effects of independent variables t, R, and S on the FRAP response values for vortex-assisted extractions best fitted the experimental data (R2 0.957), with optimal extraction conditions of t = 300 s, R = 50 g, and S = 25%.

Physicochemical Characterization, Antioxidant and Tyrosinase Inhibitory Activities of Coffea Robusta Monofloral Honey from Dak Lak Province, Vietnam.

Robusta coffee blossom honey stands as a key regional product in Dak Lak province, Vietnam. Despite its significance, there exists a dearth of scientific data for assessing its quality. This study aims to fill this gap by characterizing the physicochemical properties and biological activities of coffee blossom honeys from three distinct sub-regions within Dak Lak province, Vietnam. These activities include ferric reducing power (FRP), DPPH and ABTS radical scavenging, as well as tyrosinase inhibitory activities. Moreover, the study compares these honey samples with other popular varieties in Vietnam, such as Lychee and Longan honeys. The physicochemical parameters of the honey samples meet the standards set by Codex Alimentarius 2001. Through UPLC analysis, eleven compounds were identified, with caffeine serving as a marker for coffee honey. Furthermore, by employing multiple factor analysis (MFA), it was observed that certain physicochemical properties correlate positively with tyrosinase inhibitory, DPPH, ABTS free radicals scavenging activities, and FRP. Notably, tyrosinase inhibitory activity exhibited a positive correlation with antioxidant activity. These findings underscore the high quality of Coffea robusta honey, showcasing its potent antioxidant and tyrosinase inhibitory activities.

Facile synthesis of iminated lignin for enhanced free radical and lead ion scavenging capabilities.

Kraft lignin (KL) holds significant potential as a renewable resource for the development of innovative materials that are currently not fully utilized. In this study, a novel iminated lignin (IL) was synthesized by grafting primary amine lignin (N-KL) onto salicylaldehyde. The effects of the dosage and reaction temperature on the nitrogen content of N-KL were evaluated. The maximum nitrogen content in N-KL reached to 3.32 %. Characterization by spectroscopy techniques (FT-IR, XPS, and NMR), elemental analysis, and gel permeation chromatography confirmed the imination of lignin. Additionally, the antioxidant activity of the lignin samples was investigated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability. Moreover, the DPPH radical scavenging capacity of IL-6 (IC50 = 38.6 ± 3.9 µg/mL) was close to that of commercial antioxidant butylated hydroxytoluene (BHT) (IC50 = 37.7 ± 4.5 µg/mL). Furthermore, the adsorption equilibrium results indicated that IL-6 had a maximum uptake of 115.6 mg/g Pb2+, which was 3.2-fold higher than that of KL. Kinetic adsorption experiments suggested that IL-6 adsorption follows a pseudo-second-order model. Therefore, the synthesized iminated lignin is a promising candidate for the development of environmentally friendly materials with applications as an antioxidant and lead-ion adsorbent.

Phytofabrication of biocompatible chitosan-based ZnO nanocomposite aided by Cissus quadrangularis extract enriched with antimicrobial and antioxidant potential.

A dynamic chitosan-based ZnO nanocomposite (NC) was fabricated via a cost-effective formulation and an eco-friendly procedure utilizing Cissus quadrangularis (CQ) plant extract. This study investigates the antimicrobial and antioxidant properties, together with the cytocompatibility aspects of chitosan-incorporated ZnO nanocomposite (CS-ZnO/CQE). The formation and structural morphology of the nanocomposites were examined using FTIR, UV-Vis, XRD, XPS, BET, TGA, SEM, and TEM techniques. The antibacterial test results demonstrated the greatest inhibitory zone diameter against S. aureus (19 ± 1.00 mm) and E. coli (17 ± 1.05 mm), assessed through agar well diffusion method. Also, the composite exhibited a DPPH inhibition rate of 78.7 ± 0.34 %, indicating its high effectiveness in neutralizing free radicals. In addition, the nanocomposite exhibited less toxicity towards human erythrocytes, HDF and HEK-293 cells as a result of the biocompatibility exhibited by CS, ZnO, and CQ plant extract. Likewise, it has exceptional cell migratory capacity and possesses biodegradability factors. These observations strongly suggest the potential of CS-ZnO/CQE as a cutting-edge antibacterial and antioxidant agent to be implemented in the medical sector.

Development of cellulose nanowhisker-gallic acid antioxidant bioconjugate via covalent conjugation and supramolecular interactions: A comparative study.

A new supramolecular antioxidant bioconjugate based on cellulose nanowhisker (CNW) and gallic acid (GA) was developed by grafting ß-CD on the surface of CNW and then employing host- guest chemistry to involve GA. Our challenge was to explore the effect of supramolecular conjugation of antioxidant molecules versus their covalent binding on the CNW backbone on the antioxidant activity. The synthesis of these products was confirmed using Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) analyses. The antioxidant activity of gallic acid (GA) containing products, both products including its non-covalent interactions with CNW-g-ß-CD and covalent bonding with CNW were experimentally evaluated using DPPH test. Theoretical calculations using Gaussian software and the density functional theory (DFT) method were also performed. The results showed that GA's antioxidant activity increased in non-covalent conjugated form. Hydrogen atom transfer (HAT) was used to predict the antioxidant activity of GA in computational methods. These findings not only expand our understanding of the structure-activity relationships in antioxidant systems but also provide valuable insights that can aid in the design and development of novel biopolymer-based antioxidants with improved properties.

Direct electrospinning for producing multiple activity nanofibers consisting of aggregated luteolin/hydroxypropyl-gamma-cyclodextrin inclusion complex.

Hydroxypropyl-gamma-cyclodextrin (HPγCD) inclusion complex nanofibers (Lut/HPγCD-IC-NF) containing Luteolin (Lut) were prepared by electrospinning technology. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectra confirmed the formation of Lut/HPγCD-IC-NF. Scanning electron microscopy (SEM) images showed that the morphology of Lut/HPγCD-IC-NF was uniform and bead-free, suggesting that self-assembled aggregates, macromolecules with higher molecular weights, were formed by strong hydrogen bonding interactions between the cyclodextrin inclusion complexes. Confocal laser scanning microscopy (CLSM) images showed that Lut was distributed in Lut/HPγCD-IC-NF. Proton nuclear magnetic resonance (1H NMR) spectroscopy revealed the change in chemical shift of the proton peak between Lut and HPγCD, confirming the formation of inclusion complex. Thermogravimetric analysis (TGA) proved that Lut/HPγCD-IC-NF had good thermal stability. The phase solubility test confirmed that HPγCD had a solubilizing effect on Lut. When the solubility of HPγCD reached 10 mM, the solubility of Lut increased by 15-fold. The drug loading test showed that the content of Lut in fibers reached 8.57 ± 0.02 %. The rapid dissolution experiment showed that Lut/HPγCD-IC-NF dissolved within 3 s. The molecular simulation provides three-dimensional evidence for the formation of inclusion complexes between Lut and HPγCD. Antibacterial experiments showed that Lut/HPγCD-IC-NF had enhanced antibacterial activity against S. aureus. Lut/HPγCD-IC-NF exhibited excellent antioxidant properties with a free radical scavenging ability of 89.5 ± 1.1 %. In vitro release experiments showed Lut/HPγCD-IC-NF had a higher release amount of Lut. In conclusion, Lut/HPγCD-IC-NF improved the physicochemical properties and bioavailability of Lut, providing potential applications of Lut in the pharmaceutical field.

Acid-hydrolyzed phenolic extract of parsley (Petroselinum crispum L.) leaves inhibits lipid oxidation in soybean oil-in-water emulsions.

The antioxidant activity of the natural phenolic extracts is limited in particular food systems due to the existence of phenolic compounds in glycoside form. Acid hydrolysis post-treatment could be a tool to convert the glycosidic polyphenols in the extracts to aglycones. Therefore, this research investigated the effects of an acid hydrolysis post-treatment on the composition and antioxidant activity of parsley extracts obtained by an ultrasound-assisted extraction method to delay lipid oxidation in a real food system (i.e., soybean oil-in-water emulsion). Acid hydrolysis conditions were varied to maximize total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. When extracts were exposed to 0.6 M HCl for 2 h at 80 ℃, TPC was 716.92 ± 24.43 µmol gallic acid equivalent (GAE)/L, and DPPH radical scavenging activity was 66.89 ± 1.63 %. Not only did acid hydrolysis increase the concentrations of individual polyphenols, but it also resulted in the release of new phenolics such as myricetin and gallic acid. The extract's metal chelating and ferric-reducing activity increased significantly after acid hydrolysis. In soybean oil-in-water emulsion containing a TPC of 400 µmol GAE/L, the acid-hydrolyzed extract had an 11-day lag phase for headspace hexanal compared to the 6-day lag phase of unhydrolyzed extract. The findings indicated that the conversion of glycosidic polyphenols to aglycones in phenolic extracts can help extend the shelf-life of emulsion-based foods.

Effect of employing different extraction techniques and solvents on the total phenolic content and antioxidant properties of an Iranian endemic species Zeravschania khorasanica (Apiaceae).

Zeravschania khorasanica, a species endemic to the eastern part of Iran, possesses distinct characteristics that distinguish it from its two closely related species. This research employed five different extraction techniques to identify the active components, total phenolic content and in vitro antioxidant activity of the extract. Furthermore, hydro-distillation was utilized for GC/MS analysis to determine the composition of the essential oil. The total phenolic content was estimated using the Folin-Ciocalteu assay and the antioxidant capacity was evaluated using the DPPH radical scavenging test. The findings revealed that ethanolic Soxhlet extraction yielded the highest efficiency in extracting total phenolic content (88.19 ±1.99 gallic acid mg/100g). In contrast, water maceration extraction demonstrated the highest antioxidant activity (68.1 ±5.4%). Interestingly, the study uncovered that there is no significant positive correlation between the phenolic content and the antioxidant activity of the plant. Additionally, HPLC analysis identified three phenolic constituents in the extract. The Soxhlet extraction method yielded the highest levels of chlorogenic acid (5.8 ppm), caffeic acid (4.1 ppm) and salicylic acid (10.3 ppm). As per the GC/MS analysis, a total of eleven compounds were identified. The predominant compounds were elemicin at 58.19% and trans--bergamotene at 25.78%.

Different wavelengths of LED irradiation promote secondary metabolite production in Pycnoporus sanguineus for antioxidant and immunomodulatory applications.

Pycnoporus sanguineus is a fungus of the phylum Basidiomycota that has many applications in traditional medicine, modern pharmaceuticals, and agricultural industries. Light plays an essential role in the metabolism, growth, and development of fungi. This study evaluated the mycelial growth and antioxidant and anti-inflammatory activities in P. sanguineus fermentation broth (PFB) cultured under different wavelengths of LED irradiation or in the dark. Compared to the dark cultures, the dry weight of mycelia in red- and yellow-light cultures decreased by 37 and 35% and the yields of pigments increased by 30.92 ± 2.18 mg and 31.75 ± 3.06 mg, respectively. Compared with the dark culture, the DPPH free radical scavenging ability, ABTS+ free radical scavenging capacity, and reducing power of yellow-light cultures increased significantly, and their total phenolic content peaked at 180.0 ± 8.34 µg/mL. However, the reducing power in blue-light cultures was significantly reduced, though the total phenol content did not vary with that of dark cultures. In LPS- and IFN-γ-stimulated RAW 264.7 cells, nitrite release was significantly reduced in the red and yellow light-irradiated PFB compared with the dark culture. In the dark, yellow-, and green-light cultures, TNF-α production in the inflamed RAW 264.7 cells was inhibited by 62, 46, and 14%, respectively. With red-, blue-, and white-light irradiation, TNF-α production was significantly enhanced. Based on these results, we propose that by adjusting the wavelength of the light source during culture, one can effectively modulate the growth, development, and metabolism of P. sanguineus.

Metabolomic Profiling and DNA-Fingerprinting of Newly Recorded White-Flowered Populations of Salvia lanigera Poir. in Egypt.

Salvia lanigera Poir. is a small herbaceous perennial species with violet flowers that grows in low-altitude deserts, and sandy loam. During the collection of S. lanigera, unusual populations with white flowers were found. Therefore, the two populations (violet- and white-flowered) were subjected to comparative investigations, including DNA fingerprinting, chemical composition, and biological evaluation. The two populations showed DNA variations, with 6.66 % polymorphism in ISSR and 25 % in SCoT markers. GC/MS and UHPLC/HRMS of aqueous methanol extracts, led to the tentative identification of 43 and 50 compounds in both populations. In addition, the structures of nine compounds, including four first-time reported compounds in the species, were confirmed by NMR. Furthermore, the total extracts exhibited weak radical scavenging activity against DPPH and a lower inhibitory effect towards acetylcholinesterase. In conclusion, the obtained data suggested that the white-colored flower could be an additional important character record for the Egyptian S. lanigera.

Impact of Fermentation on the Phytochemical Profile and Bioactivity Characteristics of Aqueous Matricaria recutita L. Root Extracts.

While the flowers of Matricaria recutita L., German chamomile, are widely used for medicinal and cosmetic purposes, little is known about its roots, which are used in complementary medicine for the preparation of aqueous fermented extracts for the treatment of cramps and anxiety. To broaden the understanding of the active principles involved, a model fermentation approach was developed and fermentates were compared to commercially manufactured tinctures. Coumarins and hydroxycinnamates were among the major secondary metabolites characterized using HPLC-MSn. After six months of fermentation and storage, low-molecular organic acids were detected by GC-MS. Fermentation contributed to the stabilization of antioxidant and radical scavenging activities, which were in a range of about 8-10 mg gallic acid equivalents/g dry weight and 20-24 mg trolox equivalents/g dry weight, determined by Folin-Ciocalteu and DPPH assays, respectively. In addition, antibacterial activities of the extracts against Gram-positive and -negative bacteria increased during the first week of fermentation. Fermentates were neither cytotoxic nor pro- or anti-inflammatory. Thus, fermentation of chamomile roots is a suitable method for the safe production of biofunctional aqueous chamomile root extracts that remain stable without the addition of synthetic preservatives.

Chemical Investigation and Antinociceptive Activity Evaluation of Marrubium Vulgare L. Aqueous Extract.

Marrubium vulgare L. (Lamiaceae) has a long history of use in traditional herbal medicine for the treatment of respiratory tract infections, inflammatory conditions, and pain. This study aimed to investigate the chemical composition, acute toxicity, and antinociceptive effects of the aqueous extract from M. vulgare leaves (AEMV). Antioxidant activity was evaluated using DPPH and reducing power assays. The chemical composition of AEMV was determined through LC-MS/MS, and the levels of total phenolics, flavonoids, and condensed tannins were quantified. Acute oral toxicity was assessed in male Swiss mice with a single oral dose of AEMV (1, 2, 5 g/kg). The analgesic impact was examined through writhing, hot plate, and formalin tests. Our findings not only confirmed the safety of the extract in animal models but also revealed significant antioxidant activity in AEMV. High-performance liquid chromatography (HPLC) analysis identified important bioactive compounds, with marrubiin being a major component. Furthermore, AEMV demonstrated robust antinociceptive properties in all conducted tests, highlighting its potential as a valuable natural source of bioactive compounds suitable for a wide range of therapeutic applications.

Pyrano[2,3-c]pyrazole fused spirooxindole-linked 1,2,3-triazoles as antioxidant agents: Exploring their utility in the development of antidiabetic drugs via inhibition of α-amylase and DPP4 activity.

Environment-benign, multicomponent synthetic methodologies are vital in modern pharmaceutical research and facilitates multi-targeted drug development via synergistic approach. Herein, we reported green and efficient synthesis of pyrano[2,3-c]pyrazole fused spirooxindole linked 1,2,3-triazoles using a tea waste supported copper catalyst (TWCu). The synthetic approach involves a one-pot, five-component reaction using N-propargylated isatin, hydrazine hydrate, ethyl acetoacetate, malononitrile/ethyl cyanoacetate and aryl azides as model substrates. Mechanistically, the reaction was found to proceed via in situ pyrazolone formation followed by Knoevenagel condensation, azide alkyne cycloaddition and Michael's addition reactions. The molecules were developed using structure-based drug design. The primary goal is to identifying anti-oxidant molecules with potential ability to modulate α-amylase and DPP4 (dipeptidyl-peptidase 4) activity. The anti-oxidant analysis, as determined via DPPH, suggested that the synthesized compounds, A6 and A10 possessed excellent anti-oxidant potential compared to butylated hydroxytoluene (BHT). In contrast, compounds A3, A5, A8, A9, A13, A15, and A18 were found to possess comparable anti-oxidant potential. Among these, A3 and A13 possessed potential α-amylase inhibitory activity compared to the acarbose, and A3 further emerged as dual inhibitors of both DPP4 and α-amylase with anti-oxidant potential. The relationship of functionalities on their anti-oxidant and enzymatic inhibition was explored in context to their SAR that was further corroborated using in silico techniques and enzyme kinetics.

Extraction, Isolation and Biological Activity of Two Glycolipids from Bangia fusco-purpurea.

In order to explore the extraction and activity of macroalge glycolipids, six macroalgae (Bangia fusco-purpurea, Gelidium amansii, Gloiopeltis furcata, Gracilariopsis lemaneiformis, Gracilaria sp. and Pyropia yezoensis) glycolipids were extracted with five different solvents firstly. Considering the yield and glycolipids concentration of extracts, Bangia fusco-purpurea, Gracilaria sp. and Pyropia yezoensis were selected from six species of marine macroalgae as the raw materials for the extraction of glycolipids. The effects of the volume score of methanol, solid-liquid ratio, extraction temperature, extraction time and ultrasonic power on the yield and glycolipids concentration of extracts of the above three macroalgae were analyzed through a series of single-factor experiments. By analyzing the antioxidant activity in vitro, moisture absorption and moisturizing activity, the extraction process of Bangia fusco-purpurea glycolipids was further optimized by response surface method to obtain suitable conditions for glycolipid extraction (solid-liquid ratio of 1:27 g/mL, extraction temperature of 48 °C, extraction time of 98 min and ultrasonic power of 450 W). Bangia fusco-purpurea extracts exhibited a certain scavenging effect on DPPH free radicals, as well as good moisture-absorption and moisture retaining activities. Two glycolipids were isolated from Bangia fusco-purpurea by liquid-liquid extraction, silica gel column chromatography and thin-layer chromatography, and they showed good scavenging activities against DPPH free radicals and total antioxidant capacity. Their scavenging activities against DPPH free radicals were about 60% at 1600 µg/mL, and total antioxidant capacity was better than that of Trolox. Among them, the moisturizing activity of a glycolipid was close to that of sorbierite and sodium alginate. These two glycolipids exhibited big application potential as food humectants and antioxidants.

Physicochemical Characterization, Antioxidant and Anticancer Activity Evaluation of an Acidic Polysaccharide from Alpinia officinarum Hance.

AHP-3a, a triple-helix acidic polysaccharide isolated from Alpinia officinarum Hance, was evaluated for its anticancer and antioxidant activities. The physicochemical properties and structure of AHP-3a were investigated through gel permeation chromatography, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The weight-average molecular weight of AHP-3a was 484 kDa, with the molar percentages of GalA, Gal, Ara, Xyl, Rha, Glc, GlcA, and Fuc being 35.4%, 21.4%, 16.9%, 11.8%, 8.9%, 3.1%, 2.0%, and 0.5%, respectively. Based on the results of the monosaccharide composition analysis, methylation analysis, and NMR spectroscopy, the main chain of AHP-3a was presumed to consist of (1→4)-α-D-GalpA and (1→2)-α-L-Rhap residues, which is a pectic polysaccharide with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) structural domains containing side chains. In addition, the results of the antioxidant activity assay revealed that the ability of AHP-3a to scavenge DPPH, ABTS, and OH free radicals increased with an increase in its concentration. Moreover, according to the results from the EdU, wound healing, and Transwell assays, AHP-3a can control the proliferation, migration, and invasion of HepG2 and Huh7 hepatocellular carcinoma cells without causing any damage to healthy cells. Thus, AHP-3a may be a natural antioxidant and anticancer component.