Propyl Gallate Research Articles

Solid-state fermentation as a tool to enhance the polyphenolic compound contents of acidic Tamarindus indica by-products

Abstract We investigated the solid-state fermentation process as a tool to increase the levels of polyphenolic compounds of tamarind seed flour (SF) and mixed peel and seed flour (PSF). The 80% ethanol extracts from SF showed higher total phenolic (TPC) (5467.2 mg GAE/100 g of residue d.b.) and total flavonoid contents (TFC) (122.7 mg QCE/100 g of residue d.b.) than fermented PSF. After fermentation, PSF and SF showed TPC levels increased by 67 and 524%, respectively, and TFC levels increased by 650 and 1521%, respectively, when compared with unfermented flours. Gallic acid was the dominant compound in all extracts; the extracts of fermented PSF had the highest levels of gallic acid, ethyl gallate and propyl gallate when compared with extracts of unfermented flour. Extracts from fermented and unfermented tamarind by-products showed potential as natural additives or sources of bioactive compounds.

Propyl gallate reduces the growth of lung cancer cells through caspase‑dependent apoptosis and G1phase arrest of the cell cycle.

Propyl gallate (3,4,5‑trihydroxybenzoic acid propyl ester; PG) is a synthetic phenolic antioxidant which exerts many effects on tissue and cell functions. In the present study, Calu‑6 and A549 lung cancer cells were used to examine the molecular mechanism of the anti‑growth effects of PG in relation to apoptosis and cell cycle arrest. PG inhibited the growth of both lung cancer cell types in a dose‑dependent manner with an IC50 of 800µM at24h based on MTT assays. DNA flow cytometry showed that PG induced G1phase arrest of the cell cycle in Calu‑6 and A549 cells. In addition, PG induced apoptosis in both lung cancer cell types, as evidenced by sub‑G1 cell population and AnnexinV‑stained cells. Western blot results demonstrated that PG decreased the Bcl‑2 level which was accompanied by an increase in the cleaved form of poly(ADP‑ribose) polymerase (PARP). PG also triggered loss of mitochondrial membrane potential (MMP; ∆Ψm) and decreased MMP (∆Ψm) levels in both lung cancer cell types, as assessed by FACS analysis. Furthermore, PG upregulated the activities of caspase‑3 and caspase‑8 in Calu‑6 cells. In conclusion, PG treatment inhibited the growth of lung cancer cells, especially Calu‑6 cells via caspase‑dependent apoptosis as well as G1phase arrest of the cell cycle.

Optimization of Protection Condition on the Stability of Castor (Ricinus communis) Oil Based Biodiesel using Response Surface Methodology

The effects of designed protection conditions such as different antioxidants (propyl gallate, PG and Pyrogallol, PY), antioxidant concentration (30 – 600 ppm), temperature (30˚C -120˚C) and storage period (3 – 5 days) on the oxidation stability of castor biodiesel were investigated work was to assess the effect of the antioxidants on the oxidative stability of castor biodiesel. Using the American Standard for Testing Materials (ASTM) recommended protocols to determine the changes in the physicochemical properties (acid value, p-anisidine value, peroxide value, totox value, density, kinematic viscosity and refractive index) of the castor biodiesel were measured. The protection conditions were optimized using the Response Surface Methodology (RSM) according to the Box–Behnken Design (Design Expert version 11 Statistical Software). The analysis of variance (ANOVA) of propyl gallate showed concentration levels and temperature as the most important factors in the biodiesel oxidation, whereas the day of storage was one of the lowest factors with the p-value of < 0.05 for most indicated process variables of both linear and quadratic model terms were significant. The changes in some important physicochemical values are indication of degradation occurring in the biodiesel under the set storage condition. The optimal storage conditions were observed in propygallol with the acid value (0.985 mg KOH/g), p-anisidine value (7.650 mg KOH/g) and Totox value 4.005 (mEq/kg) with the overall desirability of 0.923 based on comparatively lower acid, p-anisidine and Totox values, followed by PG. The combined use of PY/PG antioxidants didn't show a synergic or additive result that makes the mixture of those antioxidants unsuitable to boost the biodiesel stability based on their relatively higher Totox Value.

The Molecular and Functional Characterization of the Durum Wheat Lipoxygenase TdLOX2 Suggests Its Role in Hyperosmotic Stress Response.

In plants, lipoxygenases (LOXs) are involved in various processes, such as growth, development, and response to stress cues. In the present study, the expression pattern of six durum wheat LOX-encoding genes (TdLpx-B1.1, TdLpx-B1.2, TdLpx-A2, TdLpx-B2, TdLpx-A3 and TdLpx-B3) under hyperosmotic stress was investigated. With osmotic (0.42 M mannitol) and salt (0.21 M NaCl) stress imposed at the early stages of seedling growth, a strong induction of the TdLpx-A2 gene expression in the shoots paralleled an equally strong increase in the LOX activity. Enhanced levels of malondialdehyde (MDA) and increased rates of superoxide anion generation were also observed as a result of the stress imposition. Sequence analysis of the TdLOX2 encoded by the TdLpx-A2 gene revealed that it belonged to the type-1 9-LOX group. When overexpressed in E. coli, TdLOX2 exhibited normal enzyme activity, high sensitivity to specific LOX inhibitors, with 76% and 99% inhibition by salicylhydroxamic and propyl gallate, respectively, and a preference for linoleic acid as substrate, which was converted exclusively to its corresponding 13-hydroperoxide. This unexpected positional specificity could be related to the unusual TV/K motif that in TdLOX2 replaces the canonical TV/R motif of 9-LOXs. Treatment of seedlings with propyl gallate strongly suppressed the increase in LOX activity induced by the hyperosmotic stress; the MDA accumulation was also reduced but less markedly, whereas the rate of superoxide anion generation was even more increased. Overall, our findings suggest that the up-regulation of the TdLpx-A2 gene is a component of the durum wheat response to hyperosmotic stress and that TdLOX2 may act by counteracting the excessive generation of harmful reactive oxygen species responsible for the oxidative damages that occur in plants under stress.

Environmental life cycle assessment of different biorefinery platforms valorizing olive wastes to biofuel, phosphate salts, natural antioxidant, and an oxygenated fuel additive (triacetin)

Olive agro-industry is a chemical- and energy-intensive agricultural activity and given its large scale globally is faced with serious challenges from the sustainability perspective. On the other hand, different by-products and residues generated are not generally used and end up as wastes. Therefore, it is of crucial importance to design and implement innovative platforms based on circular bioeconomy and zero-discharge principles to enhance the sustainability features of the olive supply chain system. In light of that, the present study was aimed at designing and experimentally scrutinizing two olive agro-biorefinery scenarios against the conventional olive oil production system (i.e., olive/olive oil production, including olive cultivation and oil extraction). The first agro-biorefinery system included olive cultivation and oil extraction from fruit and pomace for edible use. Moreover, the remaining pomace post-oil extraction was used as an animal feed. The second agro-biorefinery system included olive cultivation, olive oil extraction, olive pomace oil extraction, and its conversion into biodiesel. In addition, crude biodiesel glycerol was also valorized into two different phosphate salts and an oxygenated fuel additive (namely triacetin), while olive oil leaves were converted into a natural antioxidant for biodiesel. The performance of the natural antioxidant against the most promising synthetic antioxidant used by the biodiesel industry (i.e., propyl gallate) was also investigated. The developed scenarios were environmentally compared using the IMPACT 2002+ method. Overall, both developed agro-biorefineries outperformed the conventional system in terms of all four endpoint damage categories. Compared to the conventional olive oil production system, the production of 1 ton of olive oil in the first and second agro-biorefinery systems was associated with 10.62% and 4.08% saving in climate change damage category, 6.73% and 11.21% saving in primary energy consumption, and 12.01% and 1.55% saving in damage to human health. In addition, the implementation of the circular bioeconomy approach in olive oil production led to 31.28% and 26.38% saving in ecosystem quality damage category for Sc-2 and Sc-3, respectively. Overall, the weighted endpoint damage categories of olive oil production could be saved by 12.27% and 4.49% if respectively, the first and second agro-biorefinery scenarios were used. These findings revealed that through the transition from linear economy-oriented olive agri-food system to a bioeconomy-oriented olive agro-biorefinery, not only a wide spectrum of value-added bioproducts could be achieved, but also the environmental impacts per each ton of olive oil produced could be mitigated.

Solubility measurement and thermodynamic model correlation of propyl gallate in pure and binary solvents from T = (293.15 to 333.15) K

The solid−liquid equilibrium data of propyl gallate in nine pure solvents and binary solvent mixtures of ethanol + n-propanol were measured over the temperature range from (293.15 to 333.15) K by using a gravimetric method under atmospheric pressure. The experimental result proved that the rising temperature led to increased solubility of the propyl gallate in all selected solvents. For pure solvents, the solubility of propyl gallate increased according to the following order: ethanol < isobutanol < ethyl acetate < methanol < n-butanol < methyl acetate < isopropanol < n-propanol < acetone. For ethanol + n-propanol mixture solvents, the solubility of propyl gallate decreased with the increase of ethanol mass fraction. The experimental solubility in each selected solvent were correlated with a series of equations, including the modified Apelblat equation, Van't Hoff equation, λh equation, NRTL equation and Wilson equation. Computational results showed that all five selected models well fitted the experimental data. Hansen solubility parameters (HSP) were also applied to explain the solubility behavior of propyl gallate. In addition, the Van't Hoff equation was used to estimate the dissolution enthalpy (∆H°sol), dissolution entropy (∆S°sol) and Gibbs energy (ΔG°sol) of propyl gallate in selected solvents.

Zein/phenolic antioxidant nanoparticles stabilized Pickering emulsions: Effect of antioxidant hydrophobicity on lipid oxidation

Due to the presence of oils and fats, emulsions undergo lipid oxidation during storage, resulting in deterioration in sensory and nutritional qualities of emulsions. Phenolic antioxidants are widely used in inhibiting lipid oxidation. We found that phenolic antioxidants could form composite nanoparticles with zein and could be utilized to prepare Pickering emulsions with strong oxidative stability. Phenolic antioxidants with different hydrophobicity (octyl gallate, Propyl gallate and gallic acid) were fabricated into nanoparticles with zein (namely, Z/OG, Z/PG, Z/GA), and the oxidative stability of the as-prepared emulsions were much stronger than Tween 20 stabilized emulsions. And the Z/OG stabilized emulsions showed stronger oxidative stability than those stabilized by Z/PG and Z/GA. We also found that the antioxidative efficiency of octyl gallate was significantly higher than propyl gallate and gallic acid in Tween 20 stabilized emulsions. Compared with the Tween 20 stabilized emulsions, the difference in antioxidation efficiency between octyl gallate, propyl gallate and gallic acid was more obvious in the Pickering emulsions due to the combined effect of physical barrier and phenolic antioxidants. The results of this study help us to improve the antioxidant efficiency of phenolic antioxidants via the rational selection of antioxidant and a well-designed Pickering stabilization strategy.

Phytochemical constituents, antibacterial screening and antioxidant activity of Albizia lebbeck (L.) Benth (Seed)

Albizia lebbeck (L.) Benth. Traditionally plant is used as anti-asthmatic, anti-inflammatory, anti-fertility and anti-diarrheal, antiseptic, anti-dysenteric, anti-tubercular, leprosy, paralysis and helminth infection. This study aimed to determine the phytochemical constituents, antioxidant and antibacterial activities. The phytochemical screening was carried out using Petroleum ether, Ethyl acetate and 70% ethanol; preliminary phytochemical screening showed the presence of alkaloids, flavonoids, carbohydrates, tannins, coumarins and saponins in plant extracts. The seeds extract of Albizia lebbeck were tested against gram-positive and gram-negative bacteria by cup diffusion method. The Petroleum ether extract showed high activity against Escherichia coli when compared with other plant extracts. The antioxidant activity was determined by using the free radical scavenging method (DPPH). The result of antioxidant activity reflected low activity as compared with standard (Propyl gallate).

Commercially available natural inhibitors of trichothecene production in Fusarium graminearum: A strategy to manage Fusarium head blight of wheat

Fusarium Head Blight (FHB) is one of the most important diseases affecting wheat production. The disease causes yield and quality losses and hinders commercialization because of frequent grain contamination with trichothecenes, sesquiterpene mycotoxins that are harmful to human and animals and act as pathogenicity factors for FHB. Although not always effective, application of fungicides is the most common method for FHB management; thus, there is an urgent need to develop new efficient and sustainable tools. We analyzed the inhibitory activity of a group of commercially available naturally occurring compounds on the production of trichothecenes and on the severity of FHB on field-grown wheat spikes inoculated with Fusarium graminearum. The gene TRI5 codifies trichodiene synthase, the enzyme that catalyzes the synthesis of trichodiene, a volatile intermediate to trichothecenes. Our first aim was to obtain a trichothecene non-producing mutant of the pathogen by gene disruption of this gene. Seventeen putative ΔTRI5 mutants produced in the laboratory were characterized for pathogenicity and trichothecene production. The target gene was correctly and efficiently replaced in more than 75% of the transformants obtained, indicating a high efficacy of the approach used for gene disruption. Selected commercially available natural inhibitors -eugenol, apocynin, caffeic acid and propyl gallate-, were used to test their effect on trichodiene production in vitro and in field-grown wheat spikes inoculated with F. graminearum, using a ΔTRI5 mutant as non-trichodiene production control. Fungal volatile organic compounds production was measured by gas chromatography coupled to mass spectrometry. Caffeic acid, apocynin and eugenol produced a significant reduction of trichodiene production in vitro. In field assays, sesquiterpene inhibition was also significant at 2 days post inoculation (dpi), showing that effective inhibition of the trichothecene precursor can be achieved through the action of commercially available naturally occurring compounds. However, at later stages (>7 dpi) the production of trichodiene was similar to that of the F. graminearum-inoculated control. At 21 dpi, FHB severity did not differ between the treatments with inhibitors and the inoculated control. Hence, further experiments are required to identify the most appropriate inhibitors concentrations and formulations to improve their bioavailability and to achieve long lasting protection against F. graminearum infections.

Phenolic compounds as antioxidants to improve oxidative stability of menhaden oil-based structured lipid as butterfat analog

Phenolic compounds, including propyl gallate, 1-o-galloylglycerol, ferulic, gallic, caffeic, rosmarinic, and carnosic acids, tocopherols, and butylated hydroxytoluene (BHT), were investigated as antioxidants to improve the oxidative stability of a structured lipid (SL) produced by the enzymatic acidolysis of menhaden oil with caprylic and stearic acids. SL had similar physical properties to butterfat but was more susceptible to oxidation. The above phenolic compounds were each added to SL as antioxidants. SL with 1-o-galloylglycerol, rosmarinic acid, or BHT showed the highest oxidative stability during an accelerated oxidation test with the total oxidation (TOTOX) value around 250 after 18 days. Oxidation induction time (OIT) using differential scanning calorimetry showed a good correlation with the accelerated oxidation test. A mixture of 1-o-galloylglycerol and tocopherols at 50:50 ppm had the strongest protective effect on SL (OIT = 115.1 min) compared to the other tested compounds or combinations at the same concentration (OIT < 100 min).

Protein Cohabitation: Improving the Photochemical Stability of R-Phycoerythrin in the Solid State.

The poor photochemical stability of R-phycoerythrin (R-PE) has been a bottleneck for its broad-spectrum applications. Inspired by nature, we studied a sustainable strategy of protein cohabitation to enhance R-PE stability by embedding it in a solid matrix of gelatin. Both pure R-PE and fresh phycobiliprotein (PBP) extracts recovered from Gracilaria gracilis were studied. The incorporation of R-PE in the gelatin-based films (gelatin-RPE and gelatin-PBPs) has improved its photochemical stability for at least 8 months, the longest time period reported so far. These results were evidenced by not only absorption but also emission quantum yield measurements (Φ). Moreover, the photostability of gelatin-RPE films upon continuous excitation with an AM1.5G solar simulator was tested and found to remain stable for 23 h after initial decreasing up to 250 min. In the end, another approach was established to allow 100% photostability for a 3 h exposure to an AM1.5G solar simulator by doping the gelatin-based film including R-Phycoerythrin with n-propyl gallate stabilized with Tween 80, allowing their use as naturally based optically active centers in photovoltaic applications.

Proteomics Reveals the Mechanism Underlying the Inhibition of Phytophthora sojae by Propyl Gallate.

Phytophthora sojae is a serious soil-borne pathogen, and the major control measures undertaken include the induction of soybean-resistance genes, fungicides, and scientific and reasonable planting management. Owing to the safety and resistance of fungicides, it is of great importance to screen new control alternatives. In a preliminary study, we observed that propyl gallate (PG) exerts a considerable inhibitory effect on P. sojae and can effectively prevent and cure soybean diseases, although the underlying mechanism remains unclear. To explore the inhibitory mechanism of PG on P. sojae, we analyzed the differences in the protein profile of P. sojae before and after treatment with PG using tandem mass tag (TMT) proteomics. Proteomic analysis revealed that the number of differentially expressed proteins (DEPs) was 285, of which 75 were upregulated and 210 were downregulated, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways primarily comprised glycolysis, tricarboxylic acid cycle, fatty acid metabolism, secondary metabolite generation, and other pathways. Among the DEPs involved in PG inhibition of P. sojae are two closely related uncharacterized proteins encoded by PHYSODRAFT_522340 and PHYSODRAFT_344464, denoted PsFACL and PsCPT herein. The CRISPR/Cas9 knockout technique revealed that PsFACL and PsCPT were involved in the growth rate and pathogenicity. In addition, the results of gas chromatography-mass spectrometry (GC-MS) showed that there were differences in fatty acid levels between wild-type (WT) and CRISPR/Cas9 knockout transformants. Knocking out PsFACL and PsCPT resulted in the restriction of the synthesis and β-oxidation of long-chain fatty acids, respectively. These suggest that PsFACL and PsCPT were also involved in the regulation of the fatty acid metabolism. Our results aid in understanding the mechanism underlying the inhibition of P. sojae growth by PG.

Effects of Temperature, Antioxidants, and High‐Vacuum Distillation on the Oxidation of Biodiesel Derived from Waste Vegetable Oil

AbstractBiodiesel offers several environmental benefits and improvements to some fuel performance properties, but its poor oxidative stability has been a major concern. Currently, the accepted practice to improve biodiesel oxidative stability is the addition of antioxidants; numerous antioxidants have been studied but their effectiveness in inhibiting biodiesel oxidation is difficult to predict due to variation with resonance stability, solubility, reactivity, and volatility. To improve prediction efforts, this study explored the Rapid Small‐Scale Oxidation Test (RSSOT) as a means to investigate how biodiesel oxidation is affected by antioxidant concentration and temperature, and compared its results with the oxidative stability index test. A weak correlation was identified due to antioxidant variation. A kinetic model expressed in temperature and induction period was developed for biodiesel before high‐vacuum distillation (HVD), after HVD and also after HVD with three concentrations of propyl gallate (PG) and tert‐butylhydroquinone (TBHQ) antioxidants. The approach was validated by comparing collected data on the oxidation of methyl oleate with kinetic parameters found in the literature. Antioxidant concentrations from 130–930 ppm were tested, and the results revealed that the apparent activation energy of biodiesel oxidation increases with increasing concentration of primary antioxidants and decreases during vacuum distillation. When treated with an increasing concentration (130–930 ppm) of PG and TBHQ, the apparent activation energies of a vacuum distilled biodiesel changed from 108.46 ± 4.45 to 112.72 ± 1.46 kJ·mol−1 and from 77.14 ± 2.25 to 89.91 ± 2.29 kJ·mol−1, respectively. These observed trends agree with both the accepted mechanism of primary oxidation of fuels and mode of action of primary antioxidants.

Inhibitory effect of propyl gallate on pulp breakdown of longan fruit and its relationship with ROS metabolism

Abstract An excessive ROS accumulation in harvested longan (Dimocarpus longan Lour.) fruit could promote the pulp breakdown and lower the fruit quality. To solve this problem, the influence of propyl gallate, one kind of ROS scavenger, on the ROS metabolism in pulp of postharvest longans and its connection with the breakdown occurrence of longan pulp were investigated. Contrasted to control samples, the propyl gallate-treated group manifested a lower index of pulp breakdown, MDA content, and production rate of O2−., but higher gene expression levels of DlSOD, DlCAT and DlAPX, higher SOD, CAT and APX activities, higher levels of AsA, flavonoid, GSH and total phenolics, and higher ability of scavenging free radicals. These results revealed that propyl gallate inhibited longan pulp breakdown occurrence, which was because propyl gallate enhanced the ROS scavenging ability and reduced ROS generation and accumulation in longan pulp. These activities involved alleviating the oxidative damage of cell membrane and the peroxidation of membrane lipid in longan pulp, which maintained the structural integrity of longan pulp cell membrane and suppressed the pulp breakdown occurrence in postharvest longan fruit.

Effect of Antioxidants on High-Temperature Stability of Renewable Bio-Oils Revealed by an Innovative Method for the Determination of Kinetic Parameters of Oxidative Reactions.

Bio-oils employed for various industrial purposes, such as biodiesel production, undergo extensive oxidation and degradation during transformation processes. Therefore, it is extremely important to predict their stability at high temperature. We report herein a new procedure based on the optically detected profile of headspace O2 concentration during isotherms at 130 °C for evaluating the oxidation kinetic parameters of several bio-oil feedstocks. The slope of O2 consumption and the induction period duration were related to the oil characteristics (molecular structure, acidity, and presence of intrinsic antioxidants or metals). The increase of the induction time caused by a standardized propyl gallate addition yielded a semiquantitative value of radical generation rate. Investigated oils included used cooking oils; mono-, di-, and triglycerides from natural sources; free fatty acids; transesterified oils; and their blends. With respect to other methods, this characterization presents the advantage of disentangling and evaluating the role of both fatty acids composition and naturally occurring antioxidants, and allows the development of rational strategies for antioxidant protection of oils and of their blends.

Characterization and antioxidant activity of trilayer gelatin/dextran-propyl gallate/gelatin films: Electrospinning versus solvent casting

In this study, trilayer films were prepared with an electrospun dextran interlayer, and gelatin outlayers fabricated by solvent casting and electrospinning, respectively. The trilayer film either with casted or electrospun outlayers showed an enhanced thermal stability, and acceptable color and opacity properties. Compared to the electrospun outlayers, the casted outlayers endowed the trilayer film with improved oxygen and water vapor barrier properties, and significantly enhanced the elastic modulus and tensile strength, indicating a greater resistance to deformation. The DPPH radical-scavenging activity assay indicated that the applied electrospun or casted outlayers effectively prolonged the release time of propyl gallate from the interlayer by 2-fold or more, with a sustained antioxidant activity. These results suggest the promising applications of multilayer films as active packaging materials with prolonged release of antioxidants to retard oil oxidation in the food industry.

Comparative study of synthetic and natural antioxidants on the oxidative stability of biodiesel from Tilapia oil

A major obstacle in the commercialization of biodiesel is its susceptibility to oxidation when exposed to air and light. Approaches to improving the oxidative stability of biofuels include the addition of antioxidants, mixing of vegetable oils or modification of the fatty ester profile. This work aimed to evaluate the physicochemical properties of biodiesel synthesized from Tilapia oil and its oxidative degradation process after addition of both natural ethanolic extract of turmeric (Curcuma longa Linn.) and synthetics butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), propyl gallate (PG) antioxidants. In addition, some thermodynamic and kinetic parameters were obtained in order to determine the activation energy during the biodiesel oxidation process from different temperatures. The physicochemical properties of biodiesel obtained after the addition of antioxidants are in accordance with current regulations, which suggests it as an excellent alternative source for the biofuel industry. The oxidative stability showed that the natural antioxidant has the best response in control of oxidative process compared to the other synthetic antioxidants. The kinetic study showed the addition of natural antioxidant to biodiesel increases the activation energy (Ea) hindering its oxidation process. These results reveal an improvement in biodiesel stability corresponding to an increase over 450%.

High modulus, fluorine-free self-healing anti-smudge coatings

Reported herein is a simple strategy for the fabrication of phenolic polyurethane coatings with self-healing and anti-smudge properties as well as good mechanical strength and optical clarity. Polydimethylsiloxane (PDMS) is incorporated to impart anti-smudge performance into urethane matrix comprised of biobased propyl gallate, hexamethylene diisocyanate trimer, and polytetrahydrofuran prepolymer. Propyl gallate is used as a reversible crosslinker to impart the self-healing properties to the coating. The reaction products were confirmed by Fourier transform infrared spectroscopic studies. Optical microscopic analysis was used to observe the self-healing behavior of polymer films. The contact angle and sliding angle tests were used to evaluate the anti-smudge ability of these polymers. Tensile test, hardness, and abrasion test were used to validate the mechanical properties of the coatings. The obtained coatings showed excellent anti-smudge properties as evident from their water, oil, ink, and hexadecane repellencies. Also, these coatings showed excellent optical clarity approach 100% transmittance. Furthermore, these coatings exhibit promising self-healing properties, which recover from 40 μm cuts in ∼10 min at 120 ℃ and in 1 h at 80 ℃. As this approach offers a simple route towards multi-functional coatings, therefore, real-world applications are anticipated for the coatings reported in this study.

Storage and thermal stability of biodiesel produced from manketti nut oil of Southern Africa origin with the influence of metal contaminants and antioxidants

Biodiesel has widely been produced from common edible oils; however, food versus fuel conflicts has motivated researchers to search for other less common feedstock for production of biodiesel. Thus, this study investigates the suitability of biodiesel made from less common manketti nut oil in terms of its thermal and long-term storage stability. Also, since biodiesel is stored in containers made of different metals; the influence of metal contaminants on the storage stability of biodiesel is also examined. Manketti Oil Methyl Ester (MOME) is synthesized by the transesterification process and characterized as per biodiesel global standards. MOME is doped with antioxidants (1, 2, 3 tri-hydroxy benzene (Pyrogallol, PY) and 3, 4, 5-tri hydroxy benzoic acid (Propyl Gallate, PG)) at different ratio to analyse its influence on the stability of MOME. Also, 2 ppm of selected metals (Co, Cu, Fe, Mn, and Ni) is doped to MOME samples with and without antioxidants and stored for 6 months in open and closed 500 ml plastic bottles. Oxidation stability is measured once a month to monitor stability of MOME. Thermogravimetric analysis is conducted to examine thermal stability of MOME. The results show that freshly-synthesized MOME has oxidation stability of 4.24 h below the European EN 14214 (8 h) and South African SANS 1935 (6 h) standards. On adding antioxidant PY and PG at 200 ppm concentration, the oxidation stability increases to 13 h and 8.5 h respectively. The result of MOME contaminated with metals shows that Cu has the highest damaging effects on oxidation stability during storage. Additionally, thermal stability analysis results exhibit that MOME has excellent thermal stability of 211.33 °C.

Reduce the Risk of Oxidation and Pathogenic Bacteria Activity by Moringa oleifera Different Leaf Extract Grown in Sudan

High Performance Liquid Chromatography (HPLC) used in this study to identified Polyphenol constituents of Moringa oleifera leaf extract by different methods (aqueous, ethanol, ethyl acetate and chloroform), it contain gallic acid, Chlorogenic acid, Catechin, Coffeic acid, Rutin, Pyro catechol, Coumaric acid, Vanillin, Ferulic acid1, Naringenin, Propyl Gallate, 4`,7-Dihydroxyisoflavone, and Cinnamic Acid at conc. (µg/15 mg) in all extracts. Ellagic acid gave the highest concentration when extracted by ethyl acetate Caffeine gave the lowest concentration. in all different extract, The effect of moringa (aqueous, ethanol, ethyl acetate and chloroform) leaf extracts against four different pathogenic bacteria Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus, were examined using Mueller Hinton Agar and measuring inhibition zone (diameter mm), were found that, there were a significant different of all moringa leaf extracts against bacteria. The study was conducted to determine the polyphenol constituents of Moringa oleifera aqueous, ethanol, ethyl acetate and chloroform leaf extract. The effect of Moringa oleifera (aqueous, ethanol, ethyl acetate and chloroform) leaf extracts against four different pathogenic bacteria.