DPPH Method Research Articles

Phytochemical studies in some varieties of soybean [Glycine max (L.) Merr.] and their hybrids

In the present investigation, an attempt has been made to congregate the phytochemical studies done on intervarietal F1 hybrids of soybean (Glycine max L.) along with their parents. The eleven F1 hybrids were obtained by intervarietal crossing done using five varieties of soybean viz Bragg(BG), NRC7(NR), Punjab1(PN), PUSA98-14(PU) and JS9560(JS).Estimation of phenols was done by FCR Method using Gallic acid as standard. The total phenolic content was found highest in the cross JSXNR and lowest in BGXNR. Total tannin content was determined using FCR method. Total tannin content was highest in NRXJS and least in BGXPN. In addition, total flavonoids were determined using Alcl3 reagent and antioxidant activity by DPPH method. Total flavonoids was found maximum in PNXNR and least in PUXPN respectively. Highest Antioxidant Activity was 50.31% in JSXPN and lowest was 39.08% in NRXJS. The results suggested that besides protein and oil contents, the phenolic contents should also be considered as an important characteristic feature of soybean seeds, and as a potential selection criterion for antioxidant activity in soybean.

Exploring the pharmacological significance of Murraya koenigii (L.) Spreng: Insights from North-East India

Murraya koenigii (L.) Spreng., is a renowned medicinal and aromatic plant having antimicrobial and broad biological activities. In the present study, the essential oil chemical profile of the leaf and floral part were analysed using GC-FID and GC-MS, and the antimicrobial activities were determined by disk diffusion assay. The scientific analysis revealed α-pinene (40.41%) was the major compound of leaf essential oil (MKL) followed by sabinene (29.66%), β-pinene (7.92%), caryophyllene (4.24%), limonene (3.39%), terpinen-4-ol (3.25%), γ-terpinene (2.63%), terpinolene (1.58%), linalool (1.32%), along with other trace components. The floral part (MKF) contains the compounds α-pinene (74.02%) as the major compound followed by β-pinene (7.17%), sabinene (5.72%), limonene (4.19%), β-myrcene (1.98%), γ-terpinene (1.47%) and terpinen-4-ol (1.41%) along with other trace compounds. The MIC result revealed essential oil showed effectiveness against Escherichia coli (40 μg/mL), Micrococcus luteus (80 μg/mL), Aspergillus fumigatus (60 μg/mL) and Aspergillus brasiliensis (80 μg/mL) for MKL while MKF did not exhibit potent antimicrobial activities. The essential oils revealed potent antioxidant potential as determined by DPPH method with IC50 values of 14.02 μL/mL (MKL) and 5.45 μL/mL (MKF) and the ABTS method with IC50 values of 5.07 μL/mL and 8.38 μL/mL in MKL and MKF respectively as compared to that of the standards. The essential oils revealed potent antidiabetic activity with 6.02 μL/mL (MKL) and 8.18 μL/mL (MKF) as that of the standard. However, both MKL and MKF were not much effective in protease inhibitory activity and anti-tyrosinase activity. The study results exhibited a potent bioactivity profile and revealed many new utilization aspects of this essential oil.

Evaluation of cytotoxicity, acute toxicity, genotoxicity and antioxidant and antigenotoxicity activities of the sarcotesta fraction of punica granatum L. rich in lectin (PgTel)

ABSTRACT Punica granatum, popularly known as pomegranate, is a fruit tree with wide worldwide distribution, containing numerous phytochemicals of great medicinal value. The aim of the present study was to determine the phytochemical profile and antioxidant potential of a protein fraction (PF) derived from P. granatum sarcotesta which is rich in lectin. In addition, the acute oral toxicity, genotoxicity and antigenotoxicity of this protein fraction (PF) from P. granatum sarcotesta was measured. The phytochemical profile of PF was determined using HPLC. The in vitro antioxidant effect was assessed using the methods of total antioxidant capacity (TAC) and DPPH and ABTS+ radical scavenging. Acute oral toxicity was determined in female Swiss mice administered a single dose of 2000 mg/kg. This PF was examined for genotoxicity and antigenotoxicity at doses of 500, 1000 and 2000 mg/kg, utilizing mouse peripheral blood cells. Phytochemical characterization detected a high content of ellagic acid and antioxidant capacity similar to that of ascorbic acid (positive control). PF was not toxic (LD50 >2000 mg/kg) and did not exert a genotoxic effect in mice. PF protected the DNA of peripheral blood cells against damage induced by cyclophosphamide. In conclusion, this PF fraction exhibited significant antioxidant activity without initiating toxic or genotoxic responses in mice.

Free radical scavenging, α-amylase, α-glucosidase, and lipase inhibitory activities of metabolites from strawberry kombucha: Molecular docking and in vitro studies

Obesity, a global issue, is linked to cardiometabolic syndrome. Dietary modification is one of the recommended modes for managing cardiometabolic syndrome. Strawberries, a functional food, and kombucha, a fermented tea beverage, have gained attention for their health benefits. This study investigated the bioactive components of strawberry kombucha drink (SKD) and their effects on antioxidant activities and improving metabolic disorder markers. An in vitro experiment was performed to determine the effect of SKD on enzymatic parameters: lipase, α-glucosidase, and α-amylase activities. In addition, antioxidant activity using the DPPH method and quantification of the radical scavenging activity were also measured. Furthermore, untargeted metabolomic profiling of SKD and molecular docking simulation were conducted. The findings suggest that SKD, rich in secondary metabolites, can inhibit lipase, α-glucosidase, and α-amylase activities. It demonstrated in vitro anti-obesity, anti-diabetic, and antioxidant properties, potentially reducing metabolic and inflammatory issues. Thus, SKD could be a therapeutic beverage to alter metabolic issues associated with obesity. Nevertheless, further preclinical study is warranted to determine SKD’s potential in vivo.

EFFECT OF POLYMER CONCENTRATION AND SURFACTANTS ON PHYSICAL CHARACTERISTICS, DRUG RELEASE AND ANTIOXIDANT ACTIVITY OF GLUTATHIONE-KAPPA CARRAGEENAN NANOSPHERES

Objective: Glutathione is one of the antioxidants widely used as an antiaging and skin lightener. Glutathione at a dose of 250 mg/d orally proved useful as an antiaging. At the same time, glutathione topical night cream is effective at a dose of 0.1% for the skin of Indonesian women. Glutathione is one of the antioxidants that has easily oxidized properties in storage. Research purpose to optimize the concentration of kappa carrageenan polymer and surfactan to obtain the optimal physical characteristics of nanosphere system analyzed based on size, PDI, yield, drug loading, entrapment efficiency, dissolution and antioxidant activity. Methods: The most commonly used method of making nanospheres is ionotropic gelation because it has proven effective, easy, and easy to apply. Ionotropic gelation is depend on the tendency of polyelectrolytes to cross connect to develop hydrogel beads often called gelispheres in the existence of counter ions. Nanospheres were prepared by aerosolization ionotropic gelation technique followed by freeze-drying. This method uses carrageenan polymers of 0.5% and 1.0% with the addition of surfactant as a stabilizer. Evaluation parameters are particle size, entrapment efficiency, drug loading, drug release and antioxidant activity. Results: The results of the nanospheres obtained were tested physically and drug activity. Nanospheres successfully formed, with size 382.67±52.24 nm, F2 325.20±4.62 nm, F3 495.39±30.61 nm, and F4 409.80±4.11 nm. The greater the polymer concentration, the greater the value of entrapment efficiency and drug content in the nanosphere. The morphology of the nanosphere is quite good, spherical, with a smooth surface. The release profile shows that glutathione release is quite good but takes a long time, namely F1 73.91±2.17%, F2 75.91±2.76%, F3 78.56±2.82%, and F4 79.56±1.34% in 480 min or 8 h. Antioxidant activity of glutathione-Kappa carrageenan nanospheres with the DPPH method showed that nanospheres have medium or medium category antioxidant activity. Conclusion: The most optimal formula is F4 with 1% kappa-carrageenan concentration and 0.6% KCl.

Chemical investigation of methanol extracts of Swietenia mahagoni leaves and its antioxidant activity

Swietenia mahagoni is among the species of trees used by the Indonesian Government for the purpose of afforestation and timber production through Perhutani Enterprise. The common use of this species as wood products has prompted investigating the chemical properties of its leaves. Based on this background, this study aimed at investigating the methanol extracts of both 2- and 3-year old S. mahagoni leaves extractives together with its antioxidants and phenols contents. The antioxidant activity was conducted through the DPPH (1,1-diphenyl-2-picrylhydrazyl) method, while the total phenolic and flavonoid content were measured through Folin-Ciocalteu and AlCl3 methods, respectively. Additionally, 24 compounds were characterized by the GC-MS, and were grouped into phenolics, fatty acids and hydrocarbons, and terpenoids. The total phenolic and flavonoid contents in both 2 and 3 years old leaves of S. mahagoni ranged from 36.4 ± 0.84 to 42.0 ± 0.18 mg GAE/g dried extract and from 2.24 ± 0.15 to 18.55 ± 1.05mg QE/g dried extract, respectively. Also, the antioxidant values were 66.45 ± 1.85% and 77.59 ±11.23%, respectively. Based on the results, the antioxidant activity of S. mahagoni leaves was indicated as a result of the presence of α-tocopherol and α-tocopherolquinone in the leaves extracts.

Phytochemical Characterization, Antioxidant, and Antimicrobial Activity of the Vegetative Buds from Romanian Spruce, Picea abies (L.) H. Karst.

This study aims to investigate the vegetative buds from Picea abies (spruce), naturally found in a central region of Romania, through a comprehensive analysis of the chemical composition to identify bioactive compounds responsible for pharmacological properties. Using HPLC/derivatization technique of GC-MS and quantitative spectrophotometric assays, the phenolic profile, and main components of an ethanolic extract from the buds were investigated. The essential oil was characterized by GC-MS. Moreover, the antioxidant activity with the DPPH method, and the antimicrobial activity were tested. Heavy metal detection was performed by graphite furnace atomic absorption spectrometry. The main components of the alcoholic extract were astragalin, quercetin, kaempferol, shikimic acid, and quinic acid. A total content of 25.32 ± 2.65 mg gallic acid equivalent per gram of dry plant (mg GAE/g DW) and of 10.54 ± 0.083 mg rutin equivalents/g of dry plant (mg RE/g DW) were found. The essential oil had D-limonene, α-cadinol, δ-cadinene, 13-epimanool, and δ-3-carene as predominant components. The spruce vegetative buds exhibited significant antioxidant activity (IC50 of 53 μg/mL) and antimicrobial effects against Staphylococcus aureus. Furthermore, concentrations of heavy metals Pb and Cd were below detection limits, suggesting that the material was free from potentially harmful contaminants. The results confirmed the potential of this indigenous species to be used as a source of compounds with pharmacological utilities.

Two tetrahydroxyterpenoids and a flavonoid from Xylocarpus moluccensis M.Roem. and their α-glucosidase inhibitory and antioxidant capacity

Context: Scientific verification of the anti-hyperglycemic potential of Kayu sarampa (Xylocarpus moluccensis), which is popularly used for diabetic medication in North Sulawesi, Indonesia, is strongly important to conduct to avoid inappropriate medication that might cause worse conditions. Aims: To investigate the anti-hyperglycemic potential of X. moluccensis stem bark ethyl acetate extract and isolated compounds through the α-glucosidase enzyme inhibitory and antioxidant capacity determination. Methods: The active compound was isolated from ethyl acetate extract of X. moluccensis stem bark. The structures of those compounds were elucidated by infrared spectroscopy, liquid chromatography–mass spectrometry, and nuclear magnetic resonance spectroscopies. To discover the anti-hyperglycemic potency, α-glucosidase enzyme inhibition assay, antioxidant assay (DPPH and FRAP), and in silico study were performed. Results: Three isolated compounds were obtained and characterized as two tetrahydroxyterpenoids compounds, namely xyloccensin E (1) and ruageanin D (2), and one flavonoid compound, namely 3,5,7,3ʹ,4ʹ-pentahidroxyflavan (catechin) (3). Compounds 1 and 3 inhibited the α-glucosidase enzyme with IC50 values of 118.60 and 55.19 µg/mL, respectively, with a competitive inhibition mechanism. This is also in line with in silico findings, and both compounds showed good binding affinity of α-glucosidase protein, which indicated their anti-hyperglycemic activity potential by inhibiting α-glucosidase enzyme. Moreover, compounds 1 and 3 showed antioxidant capacity through the DPPH method with an IC50 value of 54.69 and 2.87 µg/mL. In addition, 100 µg/mL of compounds 1 and 3 also exhibited antioxidant capacity through the FRAP method with values of 66.35 and 213.82 µmol Fe2+/g, respectively. Conclusions: The X. moluccensis stem bark ethyl acetate extract, and isolated compounds exhibit α-glucosidase enzyme inhibitory activity and antioxidant capacity, which confirms its potency as an alternative medication for hyperglycemia issues.

Chemical composition and antioxidant properties of native Ecuadorian fruits: Rubus glabratus Kunth, Vaccinium floribundum Kunth, and Opuntia soederstromiana

The native berries of South America present promising marketing opportunities owing to their high antioxidant content, notably rich in anthocyanin and phenolic compounds. However, Ecuador’s endemic fruits, primarily found in the wild, lack comprehensive data regarding their phytochemical composition and antioxidant capacity, underscoring the need for research in this area. Accordingly, this study evaluated the total phenolic, anthocyanin, flavonoid, resveratrol, ascorbic acid, citric acid, sugars, and antioxidant content of three native Ecuadorian fruits: mora de monte (Rubus glabratus Kunth), mortiño (Vaccinium floribundum Kunth), and tuna de monte (Opuntia soederstromiana). Determination of resveratrol, ascorbic acid, citric acid, and sugars was determined by HPLC analysis, and UPLC analysis was used to determine tentative metabolites with nutraceutical properties. Antioxidant capacity was assessed using cyclic voltammetry and the DPPH method; differential pulse voltammetry was used to evaluate antioxidant power. Analysis of results through UPLC-QTOF mass spectrometry indicated that R. glabratus Kunth and V. floribundum Kunth are important sources of various compounds with potential health-promoting functions in the body. The DPPH results showed the following antioxidant capacities for the three fruits: R. glabratus Kunth ˃ O. soederstromiana ˃ V. floribundum Kunth; this trend was consistent with the antioxidant capacity results determined using the electrochemical methods.

Synthesis of novel vicinal diaryl triazoles with sulfur and hydrazine linkers as highly potent anticancer and antioxidant agents

Heading the list of the critical health-related issues worldwide, cancer continues to be one of the most serious life-threatening diseases. Moreover, development of new antioxidants is a field of growing interest because some synthetic antioxidants such as BHA and BHT are now suspected to be potentially harmful to human health. Accordingly, two series of 1,2,4-triazole–ring-containing combretastatin analogs; 8a-j with sulfur linker and 9a-j with hydrazine linker were synthesized. All twenty compounds were tested in vitro for their anticancer activity on three different cancer cell lines including A549, MCF7, and HepG2. A superior cytotoxic activity of all compounds with sulfur linker (8) as compared to doxorubicin, on A549, MCF7 cancer cells, was observed. Furthermore, the best results against HepG2 were obtained for 8e, 8c, 8f and 8g. In addition, compound 8g has also exhibited strong binding affinity against estrogen receptor alpha through in silico molecular docking simulations. Moreover, the antioxidant activity of all derivatives was evaluated using FRAP assay and DPPH test. The compounds 8e, bearing 3,4,5-methoxy phenyl moiety, and 9g, carrying fluorophenyl group, were the most potent radical scavengers in the DPPH method and also had the superior capacity in the FRAP assay.

Phytochemical Profile and Antioxidant Potential of Tobacco Flower Extract in Different Solvents

Tobacco (Nicotiana tabacum) is a commercial plant that is extensively used, particularly for its leaves. Thus far, exploration on the flower part is still limited. The objective of this study was to evaluate the phytochemical profile and antioxidant activity of tobacco flower extracts in different solvents. Tobacco flowers were macerated separately in methanol, ethanol, and n-hexane. Each extract was assayed by color reaction test to detect the phytochemical content. Total phenolic content (TPC) and antioxidant activity were determined by Folin-Ciocalteu and DPPH methods, respectively. Flavonoids, saponins, alkaloids, and triterpenoids are detected in methanol and ethanol extract, anthraquinones is only detected in methanol, while glycosides and steroids are only detected in n-hexane extracts. Among the other extracts, the methanol extract was the richest in phytochemical compounds and had the highest TPC (132.589±0.662 mgGAE/g). However, tobacco flower extract in all solvents were less effective as antioxidant due to very high IC50 values (>500 µg/mL).

Exploring Varied (Green) Extraction Methods to Optimize Galia Melon Peel Antioxidant Potential

Cucumis melo L. (C. melo), commonly known as the melon, is a widely cultivated tropical fruit associated with nutritional benefits and bioactive properties. With global production reaching 40 million tons annually, the fruit processing industry generates significant waste, primarily peels, totaling 8 to 20 million tons yearly. These organic by-products are rich in bioactive compounds such as antioxidants, offering health benefits such as a reduced risk of cancer and cardiovascular diseases, as well as of diabetes and neurogenerative diseases, offering an opportunity for sustainable utilization. C. melo by-products have demonstrated various health benefits, including anti-inflammatory, analgesic, and antioxidant properties, attributed mainly to polyphenols. Recognizing the potential of melon waste, this study systematically explored different extraction methods, including stirring (ST), ultrasound (US), and pulsed electric field (PEF) methods, while considering factors such as extraction time, temperature, and solvent composition. The primary goal was to identify the most effective extraction procedures and optimal conditions for maximizing the yield of total polyphenols and antioxidant capacity (using the FRAP and DPPH methods) from C. melo peel by-products. According to the results, the optimum conditions include ST as the extraction method, an ethanolic solvent with a strength of 50%, a 150 min extraction duration, and an 80 °C extraction temperature. The maximum values of total polyphenols that can be observed are 3.75 mg gallic acid equivalents (GAE)/g of dry weight (dw) and 25.77 μmol ascorbic acid equivalents (AAE)/g dw and 34.44 μmol AAE/g dw from FRAP and DPPH antioxidant assays, respectively. The polyphenols identified were the following: gallic acid, neochlorogenic acid, catechin, chlorogenic acid, epicatechin, and kaempferol. By securing the maximum isolation of bioactive content and antioxidant activity, the research will contribute to sustainable waste management by reducing waste and developing value-added products.

DETERMINATION OF ANTIOXIDANT ACTIVITY IN OIL AND RED FRUIT JUICE (Pandanus conoideus Lamk) WITH DPPH METHOD

Antioxidant compounds play an essential role in health because they can reduce the risk of chronic diseases such as cancer and coronary heart disease. This study analyzed the antioxidant activity of red fruit oil and juice. This study used an experimental method with oil and juice obtained through boiling for 4-5 hours. The stages of the study include flavonoid qualitative tests and antioxidant activity tests using the DPPH method using UV-Vis Spectrophotometers. Based on the research results, oil and red fruit juice contain flavonoids that have the potential to be antioxidants. Antioxidant activity test with the DPPH method showed IC50 in red fruit oil products on the market at 30.11 ppm and red fruit juice at 31.80 ppm, showing vigorous antioxidant activity compared to homemade red fruit oil with an IC50 of 85.98 ppm.

TOTAL FLAVONOID CONTENT AND ANTIOXIDANT ACTIVITY OF YELLOW PUMPKIN (Cucurbita moschata Duch) FRUIT EXTRACT

Pumpkin (Cucurbita moschata Duch) is a food rich in vitamin A, vitamin C, minerals, carbohydrates, and flavonoid compounds. Flavonoids have several pharmacological activities, including as antioxidants to ward off free radicals. This study aims to determine the total flavonoid content and antioxidant activity of pumpkin fruit. The extraction of pumpkin fruit was done by the maceration method in a 70% ethanol solvent. The total flavonoid test used the colorimetric method with a 10% AlCl3 reagent and quercetin as a positive control. Antioxidant activity was tested using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The results obtained for the total flavonoid content of the ethanol extract of pumpkin fruit amounted to 1.741 mgQE/g ± 0.2438 and an IC50 value of 379.44 ppm, including the category of weak antioxidant, compared with the positive control.

Physicochemical, Antioxidant, Antimicrobial, and Sensory Characteristics of Selected Kinds of Edible Oils

The aim of this study was to determine the peroxide values, acid numbers, oxidative stability (Rancimat method), antioxidant activity (DPPH method), antimicrobial activity (disc diffusion method), sensory properties (9-point hedonic scale), and fatty acid profiles (FAME) of five edible oils purchased from local Slovakian producers—grape seed oil, flax seed oil, walnut oil, poppy seed oil, and milk thistle seed oil. The peroxide value ranged from 2.27 (milk thistle oil) to 8.51 (flax seed oil) mmol O2/kg. All these values were in accordance with regulations (upper limit of 20 mmol O2/kg). The values of the acid number ranged from 0.11 (walnut oil) to 2.49 (milk thistle oil) mg KOH/g, and were in accordance with regulations as they did not exceed the value of 4 mg KOH/g. The oxidation stability was the lowest in flax seed oil (0.18 h) and the highest in grape seed oil (2.05 h). In milk thistle oil, the highest amounts of oleic and behenic acids, in flax seed oil, the highest amount of α-linolenic acid, and in grape seed oil, the highest amount of linolic acid were determined. Antioxidant activity was the strongest in the sample of grape seed oil—65.53 mg TEAC/L (Trolox equivalent antioxidant capacity). Samples of flax seed oil showed the strongest inhibition of Candida albicans CCM 8186 (4.58 mm) and Bacillus subtilis CCM 2010 (0.31 mm). Poppy seed oil was determined to be the most inhibiting towards Klebsiella pneumoniae CCM 2318 (3.68 mm). Milk thistle oil showed the strongest inhibition of Clostridium perfringens CCM 4435 (6.31 mm). Grape seed oil was the most inhibitory towards Staphylococcus aureus subs. aureus CCM 2461 (5.32 mm). Walnut oil showed the strongest activity towards Yersinia enterocolitica CCM 5671 (6.33 mm). The sensory analysis resulted in the samples of walnut and grape seed oil being awarded the highest scores for smell, taste, and overall acceptability. The tested edible oils are rich in biologically active compounds with antioxidant and antimicrobial activities. Their consumption can have a positive effect on the functioning of the human body and its health. Proper storage conditions are, however, necessary because of the susceptibility of these oils to oxidation.

Exploring the potential of Beta Vulgaris L. Against thrombocytopenia: in vitro, in silico, phytochemicals, and antioxidant analysis

The purpose of this study was to assess anti- thrombocytopenia of beetroot extract using both in vitro and in silico methods. Additionally, antioxidant capacity, phenolic content, and flavonoid content of beetroot were determined. The extraction procedure was optimized by reflux method, the extracts obtained were examined to determine the Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) using the Folin-Ciocalteu colorimetric and aluminum chloride methods, respectively. Furthermore, antioxidant capacity was assessed using the DPPH method, while betanin concentration was determined by thin-layer chromatography. This research approach encompasses the binding acticity of ligands and target proteins, the process of docking thrombopoietin receptor (TPOr) and betanin compound using Swissdock, and the examination of docking data using the USCF Chimera software. The studies revealed that the reflux-extracted beetroot extract had a total phenol concentration of 39.72 ± 2.56 mgGAE/g. The flavonoid concentration of beetroot extract obtained using reflux extraction was 5.47 ± 0.39 mg QE/g. The qualitative test conducted using thin layer chromatography yielded data indicating that the reflux-extracted extract tested positive for betanin. The reflux approach yielded an extract with antioxidant activity (IC50) of 95.71 μg/ml. The results of the molecular docking simulation showed that the betanin compound had a ΔG value of -8.1 Kcal/mol. It interacts with multiple amino acid residues, including LEU62, PRO63, ALA64, VAL65, ASP66, ARG138, THR139, THR140, ALA141, HIS142, ALA147, ILE148, LEU150, SER151, HIS154, PRO70, ARG71, ARG102, PHE104, PHE105, PRO106, and PHE126. An in vitro study demonstrated that the extract of Beta vulgaris L. has the ability to induce blood coagulation, indicating its potential as a haemostatic agent. Additionally, in silico investigations suggest that the betanin chemicals found in beetroot serve as TpoR agonists, and it can be concluded that betanin has antithrombocytopenia potential.

Optimization of Pressurized Liquid Extraction (PLE) Parameters for Extraction of Bioactive Compounds from Moringa oleifera Leaves and Bioactivity Assessment.

Moringa oleifera leaves are rich sources of bioactive compounds with potential health benefits, including antioxidants and anti-inflammatory agents. Pressurized liquid extraction (PLE) stands out as a promising technique for effectively extracting valuable compounds from natural sources. In this study, we aimed to optimize PLE parameters, such as temperature, extraction duration, and pressure, to maximize bioactive compound (polyphenols, flavonoids, and ascorbic acid) yield from M. oleifera leaves and evaluate their antioxidant and anti-inflammatory activities. According to the outcomes of this research, the maximum achieved total polyphenol content was 24.10 mg gallic acid equivalents (GAE)/g of dry weight (dw), and the total flavonoid content was increased up to 19.89 mg rutin equivalents (RtE)/g dw. Moreover, after HPLC-DAD analysis, neochlorogenic and chlorogenic acids, catechin and epicatechin, rutin, and narirutin were identified and quantified. As far as the optimum ascorbic acid content is concerned, it was found to be 4.77 mg/g dw. The antioxidant activity was evaluated by three different methods: ferric reducing antioxidant power (FRAP), the DPPH method, and the anti-hydrogen peroxide activity (AHPA) method, resulting in 124.29 μmol ascorbic acid equivalent (AAE)/g dw, 131.28 μmol AAE/g dw, and 229.38 μmol AAE/g dw values, respectively. Lastly, the albumin denaturation inhibition was found to be 37.54%. These findings underscore the potential of PLE as an efficient extraction method for preparing extracts from M. oleifera leaves with the maximum content of bioactive compounds.

Optimization of the Effect of Temperature, Concentration and pH on Antioxidant Capacity by Gallic Acid by Response Surface Methodology (RSM)

The antioxidant capacity of gallic acid (GA) is affected by temperature and pH. Aim: To understand this phenomenon, we evaluated the optimization of conditions between temperature (2°C, -20 °C, 40 °C), pH (3,7,10) and concentrations (1 mM, 4 mM and 7 mM) to have a better antioxidant capacity by response surface methodology (RSM). Methods: The DPPH method was used to measure the percentage inhibition (%Inh). Concentrations, 23 °C and pH 7 were evaluated, respectively. Three temperatures (2°C, -20 °C, 40 °C) were combined with the same concentrations and pH in a Box-Behnken design model. Results: The combination of the three factors significantly influenced the %Inh. The factor levels that resulted in higher %Inh were 2 °C, acidic pH and 4 mM concentration. The RSM showed that the optimum conditions had %Inh values of DPPH of 87.66%, 87.11% and 88.29%, respectively. Conclusion: the antioxidant capacity of GA. at 2 °C and pH 2 creates highest antioxidant capacity of GA.

PENGARUH LAMA PERENDAMAN TEMU KUNCI TERHADAP AKTIVITAS PENGHAMBATAN RADIKAL

Fingerroot is a type of rhizome that is usually added in cooking a dish. The purpose of this study was to determine the effect of soaking time on the total phenolic compounds and radical scavenging activity of the fingerroot soaking time. Fingerroots were washed, chopped, then soaked in distilled water for 0, 10, and 20 minutes at 95°C. Afterwards, screening was carried out followed by testing for radical scavenging activity using the DPPH and ABTS methods, as well as testing for total phenolic compounds. From the results, it was obtained that zero-minute immersion time produced the highest total phenolic compounds and radical scavenging activity (DPPH method), namely 0.70 mg GAE/100g and 6.53%, respectively. Meanwhile, the radical scavenging activity using the ABTS method resulted in the highest value reaching 88.98% for 20 minutes of immersion.

Chemical analyses and antioxidant activity of the essential oils from baccharis dracunculifolia DC. In Southern Brazil

ABSTRACT Baccharis dracunculifolia DC. is a Brazilian native plant species that produce essential oil with several biological activities and cosmetic applications. This study aimed to evaluate the effect of seasonality on the yield, chemical composition and antioxidant activity of B. dracunculifolia essential oils during four seasons in Southern Brazil. The extraction of the volatile compounds was carried out by hydrodistillation and the analyses of chemical composition of the species were performed by GC-FID and GC-MS, while antioxidant activity was evaluated by the DPPH method. The samples were separated into two main groups: I) winter and spring: high levels β-pinene (15.58–16.15%) and II) summer and autumn: high levels of (E)-nerolidol (17.81–21.68%). These results suggest that B. dracunculifolia essential oil presents higher levels of (E)-nerolidol during the summer and autumn and β-pinene during winter and spring. The highest antioxidant activity (88.89%) was observed during the summer with a positive correlation with limonene (r = 0.977).