Electrochemical Properties of Phytosynthesized Gold Nanoparticles for Electrosensing

Gold nanoparticles are widely used in electrosensing. The current trend is to phytosynthesize gold nanoparticles (phyto-AuNPs) on the basis of the “green” chemistry approach. Phyto-AuNPs are biologically and catalytically active, stable and biocompatible, which opens up broad perspectives in a variety of applications, including tactile, wearable (bio)sensors. However, the electrochemistry of phytosynthesized nanoparticles is not sufficiently studied. This work offers a comprehensive study of the electrochemical activity of phyto-AuNPs depending on the synthesis conditions. It was found that with an increase in the aliquot of the plant extract, its antioxidant activity (AOA) and pH, the electrochemical activity of phyto-AuNPs grows, which is reflected in the peak potential decrease and an increase in the peak current of phyto-AuNPs electrooxidation. It has been shown that AOA is an important parameter for obtaining phyto-AuNPs with desired properties. Electrodes modified with phyto-AuNPs have demonstrated better analytical characteristics than electrodes with citrate AuNPs in detecting uric and ascorbic acids under model conditions. The data about the phyto-AuNPs’ electrochemistry may be useful for creating highly effective epidermal sensors with good biocompatibility.

Exogenous Salicylic and Ascorbic Acids Delay Peel Enzymatic Browning and Improve Quality of Dried Figs Under Low-Temperature Storage

Dried figs undergo undesirable changes during storage, particularly browning reactions. An approach to this issue is using, separately, antioxidants such as ascorbic acid and salicylic acid as anti-enzymatic browning agents. The aforementioned chemical agents were tested at the concentrations 0.1, 0.2, and 0.3% during 6 weeks-storage at 4 °C, for dried figs sealed within polyethylene terephthalate bags. For both agents, the results demonstrated that a concentration of 0.3% lowered the browning index compared to the control by 55 and 54%, respectively. Compared to other concentrations, the same concentration suppressed polyphenol oxidase to 75 and 80%, respectively. A significant impact (p < 0.05), for both treatments, particularly at 0.3%, was obtained on dried figs quality by lowering the total phenols loss and antioxidant capacity loss during the storage period. The results of vibrational spectroscopy were able to confirm the same pattern of the polyphenols compared to those examined by UV-Visible spectrophotometry, revealing thus a decreasing absorbance. A similar tendency was revealed using integrated intensity around the phenols vibration within the region of 1175–940 cm-1, as the concentrations of anti-browning agents increased. Thus, pre-storage ascorbic and salicylic acids treatments at 0.3% on dried figs could be appropriate to delay enzymatic browning and quality loss and, therefore to extend their shelf-life.

Utilization of Rosmarinic and Ascorbic Acids for Maturation Culture Media in Order to Increase Sow Oocyte Quality Prior to IVF

The beneficial effect of antioxidant supplementation in maturation culture media of sow oocytes was evaluated by the expression quantification of apoptotic genes and the genes that ensure stability of germ cells during fertilization. The oocytes were cultivated for 44 h in conventional medium (C) or in medium supplemented with 105 µM rosmarinic acid (R) and 0.5 mM ascorbic acid (A) and classified into three quality classes by morphological observation from which the total RNA was isolated. The gene expression of Ptx3 and the apoptotic regulator p53, Bax and BCL-2 were evaluated by quantitative PCR technique. The decreased expression of the Bax gene in the A and R groups, compared to the control, indicates a protective role of antioxidants in the cells. Cell homeostasis was maintained, as reflected in the ratio of Bax/Bcl-2 in class I COCs (cumulus-oocyte complex) regardless of the experimental group, indicating minimum cellular stress. The expression of p53 genes was higher in all class III COC, but in A1 and R1 the expression was lower than in C1, and a similar Ptx-3 gene decreased significantly in groups A1, A2, A3 and R1 compared with control groups. Antioxidant supplementation showed beneficial effects on all morphological classes of pig COCs.

Apiaceae as an Important Source of Antioxidants and Their Applications

The excess level of reactive oxygen species (ROS) disturbs the oxidative balance leading to oxidative stress, which, in turn, causes diabetes mellites, cancer, and cardiovascular diseases. These effects of ROS and oxidative stress can be balanced by dietary antioxidants. In recent years, there has been an increasing trend in the use of herbal products for personal and beauty care. The Apiaceae (previously Umbelliferae) family is a good source of antioxidants, predominantly phenolic compounds, therefore, widely used in the pharmaceutical, cosmetic, cosmeceutical, flavor, and perfumery industries. These natural antioxidants include polyphenolic acids, flavonoids, carotenoids, tocopherols, and ascorbic acids, and exhibit a wide range of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis, and anticancer. This review discusses the Apiaceae family plants as an important source of antioxidants their therapeutic value and the use in cosmetics.

The Role of Vitamin C in the Energy Supply of Cells Hypothetical Structure for Energy Transformation

The present paper represents a hypothetical structure, the structure for energy transformation (SET), which might be responsible for the proper energy transformation steps leading to the continuous production of H+ and ATP in living cells. We predict that the electron flow is realized through the electron flow device (EFD). We suppose that there are several versions of the SET. Two of them are described below [Structure of Aerobic Glycolysis (SET-AG) and Structure of Oxidative Phosphorylation (SET-OP). The hypothesis is based on the atom properties of the protonated adenine molecule and the docking computations of molecular mechanics involved, suggesting that two ascorbate molecules may occupy the empty NADPH pocket, preferably binding to the adenine binding site. We hypothesize that the adenine originates from uric acid (UA), resulting in an ATP-UA-ADP-ATP-UA cycle. It would also mean that UA is one of the oxygen sources in aerobic glycolysis. We also suppose that the EFD contains the well-known molecules of the Nicotinamide Adenine Dinucleotide (NAD) and Flavin Adenine Dinucleotide (FAD) supplemented with two additional UA-originated adenine molecules, two L-ascorbic acids, and two D-glucose molecules. Based on all this, we surmise that a tetra adenine octo phosphate ring (TAR) exists, in which the UA originated adenine molecules form a ring. The molecules are linked to each other through the N7-C2 and C8-N1 atoms of the adenine molecules by H2PO4e- molecules. The four N10 atoms of the adenine molecules bind one flavin, one nicotinamide, and two L-ascorbic acid molecules. Six D-glucose molecules complete one Unit of the structure. Both Fe-S and cytochrome clusters, as well as dehydrogenases, ensure the continuous operation of the Unit. The synchronized function of the three-stoke, three twin-cylinder engine results in continuous energy, ATP, and H+ production. Eukaryotic cells are equipped with the SET-AG and the SET-OP; thus, they can live in an anoxic and oxygenized environment. It is hoped that the SET concept developed here will help the better understanding the way of cancer treatment’s action regarding glucose deprivation or Vitamin C.

Comparison of acid degumming methods and their influence on the formation of 3-MCPD-esters and glycidyl esters in sunflower oil deodorization

Degumming is the first stage in processing of vegetable oils, and it is aimed at removing phospholipids. The article compares the results of degumming by phosphoric and citric acids, their effects on the extraction of calcium and magnesium ions from oils, these ions being the main components of nonhydratable phospholipids. We showed the appropriateness of combining citric and succinic acids (the final content of phospholipids in oil was 0.034%, whereas it was equal to 0.048% when citric acid was used) and citric and ascorbic acids (the final content of phospholipids in oil was 0.040%). We studied the effect of acid degumming on the formation of 3-MCPD-esters and glycidyl esters. The content of glycidyl esters after degumming with citric acid and phosphoric acid was 310 g kg–1 and 200 g kg–1, respectively. After degumming with citric acid and phosphoric acid, the content of 3-MCPD-esters in the deodorized oil was 680 g kg–1 and 470 g kg–1, respectively. On the contrary, aqueous degumming does not increase the content of these esters in the deodorized sunflower oil (the content is less than 100 g kg–1) and its implementation can be recommended as one of the ways to prevent the formation of these toxic substances during deodorization.

Aluminum Chloride-Induced Oxidative Damage to Serum and Combined Intervention of Ascorbic Acids and Massularia Acuminata On Selected Markers Of In Vivo Antioxidant Enzymes in Wistar Rats

This study evaluates the synergistic antioxidants effects of extracts of Massularia acuminata and ascorbic acid in aluminum chloride-treated oxidative stress in wistar albino rats with a view to investigate the preventive potential of co-administration of Massularia acuminata and ascorbic acids. The in vivo antioxidant properties of the extract were evaluated using in vivo catalase activity, superoxide dismutase activity and thiobarbituric acid reactive substances assay by standard methods via spectrophotometry. The in vivo studies were carried out on rats, grouped majorly into positive control, negative control and the treated groups. The positive control group was administered with normal saline (distilled water) orally, while the negative control group was orally induced with the toxicant (aluminium chloride). The treated group was orally administered with the extract after toxicant administration. Ascorbic acid was used as standard antioxidant in the study. The effects on enzymatic antioxidants and lipid indices were evaluated. Forty healthy Wistar rats sub-grouped into ten (10) groups were induced with aluminum chloride. Some rats were treated with ascorbic acid which is a well-known antioxidant, while others were treated with various extracts of Massularia acuminata (Pako Ijebu) at various doses. The experiment is designed as follows: in Group 1, animals were used as control group. Animals in Group 2 were the toxicant-treated groups administered with AlCl3 (34 mg/kg body weight). Ascorbic acid treated groups are the standard control (group 3) administered with 200 mg/kg body weight. Animals in Group 4 were co-treated with AlCl3 and Ascorbic acid (34 mg/kg aluminum chloride and 200 mg/kg body weight of ascorbic acid). Animals in group 5 were co-administered with ethanolic extract (50 mg/kg body weight) of Massularia acuminata and AlCl3 (34 mg/kg body weight), respectively. Animals in group 6 were also co-treated and administered with ethanolic extract of Massularia acuminate (100 mg/kg body weight) and AlCl3, respectively. Experimental animals in group 7 were equally co-administered with methanolic extract of Massularia acuminate (50 mg/kg body weight) and AlCl3, respectively. Animals in group 8 were co-administered with methanolic extract of Massularia acuminate (100 mg/kg body weight) and AlCl3, respectively. Group 9 animals were co-administered with butanolic extracts of Massularia acuminata (50 mg/kg body weight) and AlCl3, respectively. Group 10 experimental animals were also co-administered with butanolic extract of Massularia acuminate (100 mg/kg body weight) and AlCl3, respectively. At the end of the experiment, the animal was sacrificed after three weeks by cervical dislocation after they were immobilized using chloroform. Results show that ethanolic and methanolic extracts of Massularia acuminata contain antioxidant properties. Both doses of ethanolic extract dose (50 mg/kg and 100 mg/kg body weight) group of methanol extract also reduced the level of MDA but not as ascorbic acid group. Both doses of methanolic extract of Masssularia acuminata act contrariwise from other extracts in that they show the highest level of malonaldehyde even more than AlCl3. The results of superoxide dismutase (SOD) assay test in this study show that the control group, ascorbic acid combined with AlCl3 group, 50 mg/kg body weight of ethanolic extract. Both doses of methanolic extract groups have the same comparative value of SOD. The group treated with toxicant (aluminum chloride) and ascorbic group has similar relative value. The group treated with 50 mg/kg body weight of butanolic extract shows the highest value of superoxide dismutase activity that follow closely by 100 mg/kg of ethanolic extract group. The study concluded that Massularia acuminata, like ascorbic acids, can induced antioxidant enzymes such as SOD and CAT in aluminium chloride-induced oxidative stressed rats. It may therefore be used to protect the body against any pathological attacks from free radical and oxidative insults.

Silica and Silica–Titania Xerogels Doped with Iron(III) for Total Antioxidant Capacity Determination

In order to design a sensor material for total antioxidant capacity determination we have prepared silica and silica–titania xerogels doped with iron(III) and modified with 1,10-phenanthroline. Titanium(IV) tetraethoxyde content in the precursors (titanium(IV) tetraethoxyde and tetraethyl orthosilicate) mixtures has been varied from 0 to 12.5% vol. Iron(III) concentrations in sol has been varied from 1 to 100 mM. The increase of titanium(IV) content has led to a decrease in BET surface area and average pore diameter and an increase of micropore surface area and volume, which has resulted in better iron(III) retention in the xerogels. Iron(III), immobilized in the xerogel matrix, retains its ability to form complexes with 1,10-phenanthroline and to be reduced to iron(II). Static capacities for 1,10-phenanthroline have been determined for all the iron(III) doped xerogels (0.207 mmol/g–0.239 mmol/g) and they are not dependent on the iron(III) content. Sensor materials—xerogels doped with iron(III) and modified with 1,10-phenanthroline—have been used for antioxidants (catechol, gallic and ascorbic acids, and sulphite) solid phase spectrophotometric determination. Limits of detection for catechol, gallic and ascorbic acids, and sulphite equal 7.8 × 10−6 M, 5.4 × 10−6 M, 1.2 × 10−5 M, and 3.1 × 10−4 M, respectively. The increase of titanium(IV) content in sensor material has led to an increase of the reaction rate and the sensitivity of determination. Proposed sensor materials have been applied for total antioxidant capacity (in gallic acid equivalents) determination in soft beverages, have demonstrated high stability, and can be stored up to 6 months at room temperature.

Determination of phenolic compounds in medicinal preparations by galvanostatic coulometry

In this work, the possibility of using reactions of electrogenerated titrants with phenolic compounds was studied and a method for their coulometric determination in medicaments by galvanostatic coulometry was developed. The research objects were: rutin, salicylic acid and drugs containing phenolic compounds such as «Ascorutin», «Salicylic Paste» and «Salicylic Ointment» of Russian manufacture. Electrogenerated halogens (Cl2, Br2 and I2) and hexacyanoferrate(III)-ions were used as titrants. It was found that for the quantitative determination of phenolic acids, the optimal reagent is electrogenerated bromine, for rutin - electrogenerated bromine and iodine, and for ascorbic acid - any of the studied electrogenerated titrants (Cl2, Br2, I2 and [Fe(CN)6]3-). The correct definition was checked by the «entered-found» method, the error does not exceed 2%. As experimental studies have shown, our method of coulometric titration with electrogenated bromine and iodine is characterized by good reproducibility of results, expression, accuracy and can be used to determine phenolic compounds in drugs, for example, «Ascorutin» tablets. It should be noted that by our procedure it is possible to determine the spectrum of phenol-containing compounds (rutin, ascorbic and salicylic acids) in drugs without their preliminary separation. Therefore, the coulometric method using electrogenerated titrants can be recommended for the determination of salicylic, ascorbic acids and rutin in dosage forms. The proposed method is accurate and eliminates the experiment error in comparison with the Pharmacopoeic method.