Source Of Natural Antioxidants Research Articles

Process Optimization and Characterization of Polysaccharides with Potential Antioxidant and Hypoglycemic Activity from Cissus repens.

Ultrasound-assisted extractionof Cissus repenspolysaccharides (CRPs) was optimized through response surface methodology (RSM) based on Box-Behnken design (BBD).The maximum CRPsyield (16.18%) was achieved under the optimum extraction conditions: extraction time 72 min, extraction temperature 74 ℃, extraction power 240 W.Then three-phase partitioning (TPP) method combined with gradient alcohol precipitationwas used to obtained CRP20,CRP40, CRP60 and CRP80 from CRPs, and CRP80 has a higher purity than others.Theprimary chemical and structural characteristics of CRP80 were investigated by UV, FT-IR, high-performance liquid chromatography (HPLC) and high-performance gel-permeation chromatography (HPGPC).CRP80 is mainly composed of glucose, galactose, arabinose and mannose, with a molecularweights of approximately 2.95kDa. Furthermore, the antioxidant activity and hypoglyceamicactivity of CRP80 in vitrowere evaluated. The results showed that CRP80 had strong scavenging activities on ABTS, hydroxyl and DPPH radicals, as well as high scavenging activities on α-glucosidase andα-amylase. Our research providedan efficient method for the extraction of polysaccharidesfrom C. repensandCRP80 haspotential as a promising source of natural antioxidants and hypoglycemic agent for the functional food and medicinal industries.

Antioxidant activity of Eucheuma cottonii Seaweed Extracts from Central Mawasangka Waters

Eucheuma cottonii is one type of seaweed that has the potential to be an antioxidant. This seaweed grows and is distributed in various waters of Indonesia, especially in Southeast Sulawesi. However, information regarding the antioxidant activity and the compound content of E. cottonii in this area is still limited. Therefore, this research aims to determine the compound and antioxidant activity profile in E. cottonii. The study used laboratory experimental methods. The research stages were preparation (seaweed sampling), extraction, qualitative phytochemical screening, and antioxidant assay. The initial identification of compounds using qualitative phytochemical screening methods with three extraction solvents: ethanol, ethyl acetate, and n-hexane. Meanwhile, the antioxidant test employed the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The results of qualitative phytochemical screening revealed that the seaweed extract of E. cottonii contains saponins, tannins, and terpenoids. The antioxidant assay using the DPPH method indicated that among the three extraction solvents used, ethanol extract exhibited a very strong antioxidant activity (with an IC50 of 30,036 ppm), compared to ethyl acetate extract (IC50 of 182,179 ppm) and n-hexane extract (IC50 of 641,454 ppm). This study concluded that E. cottonii seaweed has the potential to be developed as a source of natural antioxidants or raw material for the discovery of antioxidant medicines in the future.

Utilization of Rosella as a Natural Color and Source of Antioxidants for Soybean Hull Nata

Utilization of Rosella as a Natural Color and Source of Antioxidants for Soybean Hull Nata

PHENOLIC AND ANTIOXIDANT PROFILE: FTIR AND LC-MS ANALYSES OF SERAPIAS ORIENTALIS

Objective: The objective of this study is to characterize the aerial parts of S. orientalis using Fourier Transform Infrared (FTIR) spectroscopy, evaluate the phenolic content and antioxidant activity of seeds, stems, and flowers, and conduct quantitative analysis of phenolic compounds using LC-MS/MS. Material and Method: Fourier Transform Infrared (FTIR) spectroscopy was employed to characterize the aerial parts of S. orientalis. The analysis focused on identifying various functional groups such as -OH vibrations associated with polysaccharides, C-H vibrations from lipids and lignin compounds, and C=O vibrations related to cellulose derivatives. The total phenolic, flavonoid, flavanol, tannin, and proanthocyanidin contents of S. orientalis seeds, stems, and flowers were evaluated using standard analytical methods. DPPH radical scavenging activity was determined to assess antioxidant potential, with IC50 values calculated for each plant part. Quantitative analysis of phenolic compounds in the plant extract was conducted using LC-MS/MS. The abundance of various phenolic acids including P-coumaric acid, trans-ferulic acid, caffeic acid, and vanillic acid was determined. Additionally, other phenolic compounds such as gallic acid, chlorogenic acid, salicylic acid, (+) taxifolin, rutin hydrate, ellagic acid, quercetin dihydrate, and apigenin were also detected and quantified. Result and Discussion: The evaluation of phenolic content showed differences among different plant parts, with flowers exhibiting the highest total phenolic and proanthocyanidin content. Seeds demonstrated superior DPPH radical scavenging activity. Quantitative analysis of phenolic compounds using LC-MS/MS highlighted the abundance of various phenolic acids and other phenolic compounds in S. orientalis. These findings underscore the potential of S. orientalis as a valuable source of natural antioxidants. Overall, the results suggest that S. orientalis possesses significant phenolic diversity and antioxidant activity, which could contribute to its potential applications in various industries, including pharmaceuticals and nutraceuticals.

Quantitative and Qualitative Production of Species Cucumis metuliferus and the Potential for Adaptation in the Context of Current Climate Change.

Cucumis metuliferus E. Meyer ex Naudin belongs to the family Cucurbitaceae. It is an annual vegetable species known as horned melon or kiwano. Fruits are recommended for the daily diet because they provide vitamins, minerals, and phytochemicals to alleviate malnutrition and improve human health. In this study, kiwano was cultivated in the climatic conditions of Southwestern Romania, which is characterized by warm summers, lower precipitation, and high temperatures, ensuring optimal conditions for growth and development. The fruits were harvested at three stages of consumption: immature stage (green), intermediate stage (white-yellow) or the mature stage (yellow-orange). They were also subjected to analysis on the productive yield and physical-chemical properties. The results showed that the number of fruits ranged from 13.9 to 15.3 fruits/plant, and their average weight had values from 204 g to 234 g, depending on the harvest stage. The results obtained for bioactive compounds and antioxidant activity indicated significant differences (p ≤ 0.05), depending on the harvesting stage. The highest values for the antioxidant capacity (140.90 μM TE/100g DPPH) and total polyphenols (48.78 TPC mg/100 g) were recorded in the immature fruit phase, as well as for the carbohydrate content (3.56%), total protein (1.98%), ascorbic acid (4.3 mg/100 g f.w.), and carotene (0.98 mg/100 g) in the mature fruit phase. These results may stimulate interest in the introduction of this species as a niche crop and for consumption as a source of natural antioxidants for the prevention of diseases due to oxidative stress.

Potential assessment of Chrysanthemum flowers from various cultivars as sources of natural antioxidants and bioactive compounds

Potential assessment of Chrysanthemum flowers from various cultivars as sources of natural antioxidants and bioactive compounds

Assessment and comparative analysis of the antioxidant capacity of some food waste for fish oils

The aim of the present study was to compare the antioxidant capacities of butylated hydroxyl anisole and tocopherol with polar extracts obtained from some food waste such as date seed, walnut shell, sesame hull, spent coffee and spent black tea. In pursuit of this objective, crude fish oil was employed as a control sample, with all extracts added at a concentration of 200 ppm, equivalent to BHA. The acid, peroxide, conjugated dien, viscosity, total chlorophyll and carotenoid contents in the fish oil were monitored during the storage period (60 days) at 25 °C and 35 °C. The date seed and walnut extracts presented higher antioxidants and oxidative stability than the others at the end of the storage period at both temperatures. The findings of the present study showed that the extracts obtained from food wastes/by-products could be evaluated as a natural source of antioxidants, especially for oils which are highly susceptible to oxidation.

Bioactive Compounds from Kinnow Processing Waste and their Associated Benefits: A Review.

We have explored the expansive possibilities of kinnow peel, a frequently ignored by-product of the fruit processing industry, in this thorough analysis. The production of kinnow generates a significant amount of waste, including peel, seeds, and pulp. The disposal of this waste is a major environmental issue, as it can lead to pollution and greenhouse gas emissions. Due to the presence of bioactive substances that may be used in a variety of sectors, kinnow processing waste has the potential to provide a number of advantages. In the culinary, pharmaceutical, and cosmetic industries, the peel, seeds, and pulp from kinnow can be used as natural sources of antioxidants, aromatics, pectin, and dietary fibre. Utilizing kinnow waste promotes eco-innovation, increases sustainability, and aids in waste reduction. The development of a circular economy can be sped up with more study and commercialization of kinnow waste products. This analysis emphasises how important it is to understand and utilise the unrealized potential of agricultural byproducts, like kinnow peel.

In vitro antioxidant and antibacterial activities of aqueous extract of microalgae strain MRB-1, MRB-2, and MRB-3

Abstract The awareness growth of human health encourages market demand of functional food. Microalgae are promoted as natural resources for functional food, food additives and food preservatives, considering their metabolites and nutrient-rich components with diverse pharmacological activities. This study aims to evaluate the phytochemicals, antioxidant, and antibacterial activities of aqueous extracts of microalgae strain MRB-1, MRB-2, and MRB-3. The morphological surface of microalgae cells was analyzed using Scanning Electron Microscopy (SEM). The metabolites of the extract were conducted using Liquid Chromatography-High Resolution Mass Spectroscopy (LC-HRMS) with positive and negative ion modes. In addition, the antioxidant activity was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the antibacterial activity was assessed using the agar disk-diffusion method against gram-positive bacteria (Staphylococcus aureus ATCC 25923) and gram-negative bacteria (Escherichia coli ATCC 8739). The total phenolic contents (TPC) of the extract was determined using the Folin-Ciocalteu assay. The result revealed that the aqueous extract of microalgae strain MRB-1 had the highest scavenging activity toward DPPH radicals with a value of 24.33±1.44% at 0.8 mg/mL. This data was in accordance with the TPC of the extract, whereas the highest TPC was also obtained from strain MRB-1 extract (17.73±0.64 mg GAE/g extract). Meanwhile, the MRB-2 extract had the highest inhibition activity against S. aureus, with a value of 11.78±2.06 mm at 18 mg/mL. The results of this study indicated that microalgae from the peatlands potentially benefit to human health as a natural antioxidant and antibacterial source.

Unveiling the phytochemical profile and biological potential of five Dendrobium species

Dendrobium, a genus of orchids celebrated for their ornamental, medicinal, and culinary uses, is the focus of this study, which examines the metabolite profiles and bioactivity of five species: Dendrobium officinale, Dendrobium nobile, Dendrobium crepidatum, Dendrobium chrysotoxum, and Dendrobium denneanum. Utilizing UPLC-Q-TOF-MSE analysis, we have identified 88 compounds from the stems and leaves of these species. Notably, extracts from D. denneanum and D. chrysotoxum exhibited the highest antioxidant activities as demonstrated by DPPH, ABTS radical scavenging, and FRAP assays. Additionally, D. officinale showed significant anti-hepatoma activity with an IC50 value of 104 μg/mL. Multivariate analysis, hierarchical cluster analysis, and metabolites correlation analysis further elucidated the bioactive potential of these species. This comprehensive approach revealed distinct metabolite profiles that correlate with the observed bioactivities. The antioxidant activities of D. denneanum and D. chrysotoxum were particularly noteworthy, suggesting their potential as natural sources of antioxidants for pharmaceutical and nutraceutical applications. The anti-hepatoma activity of D. officinale, with its notable IC50 value, indicates its promise as a therapeutic agent against liver cancer. The findings underscore the richness of bioactive compounds in Dendrobium species, highlighting their antioxidant and anti-hepatoma properties. These insights pave the way for further research into the medicinal utilization of Dendrobium leaves and contribute to the development of novel applications in healthcare and wellness industries. The potential health benefits identified in this research emphasize the importance of preserving and studying these valuable plant species for their diverse bioactivities.

Effect of pasteurization time and temperature on the physico-biochemical properties of soursop (Annona muricata L.) juice

This study aimed to determine the effect of pasteurization time and temperature on soursop juice characteristics. Soursop (Anonna muricata L.), a climacteric fruit, is a high source of natural antioxidants and contains polyphenol oxidase (PPO) enzyme, which causes browning and can reduce the phenol content in fruit which can reduce antioxidant activity. The pasteurization process was carried out to inactivate PPO in soursop juice production. Soursop juice was prepared from soursop fruit pulp pasteurized at temperatures (56, 62, 68, 74, and 80 oC) for various pasteurization times (5, 10, and 15 minutes). Time and temperature of pasteurization had a significant effect (ρ < 0.05) on physical characteristics (Total Soluble Solid/TSS, viscosity, pH, and colour), polyphenol oxidase enzyme activity, antioxidant activity, and microbial population. Pasteurization at 62 ˚C for 5 minutes can maintain antioxidant activity with the greatest total phenol of 85.45 ± 3.5 mg GAE/100 g, total flavonoid of 71.38 ± 6.9 mg QE/100 g, and antioxidant activity of 76.91 ± 0, 33%. Pasteurization at 80 ˚C for 15 minutes can reduce the total number of bacteria from 350 ± 24 CFU/mL to 54 ± 22 CFU/mL, which has a TSS value of 13.73 ˚brix, viscosity of 928.67 mPa, pH of 4.40, a total colour change of 0.556, and has the lowest PPO enzyme specific activity of 0.0005 U/mg with enzyme inactivation of 93%.

The potency of yellow pigment extract from the marine bacterium Pseudomonas oryzihabitans SAB E-3 as an antioxidant agent

Abstract. Putri DA, Astuti RI, Wahyudi AT. 2024. The potency of yellow pigment extract from the marine bacterium Pseudomonas oryzihabitans SAB E-3 as an antioxidant agent. Biodiversitas 25: 2565-2575. Metabolic processes in cells can produce byproducts in the form of Reactive Oxygen Species (ROS). Excessive amounts of ROS are one of the causes of oxidative stress. Antioxidants are known to act as free radical-scavenging compounds. Pigment-producing bacteria associated with sponges have been widely reported to have antioxidant compounds. In this study, the marine bacterium Pseudomonas oryzihabitans SAB E-3 produced intracellular yellow pigments with potential antioxidant activity. Therefore, this study aimed to assess the in vitro antioxidant and mitochondrial activity at the cellular level and identify chemical compounds. The intracellular pigments produced by P. oryzihabitans SAB E-3 were extracted using methanol, acetone, chloroform, and ethyl acetate. The methanol pigment extract contained the highest number of phenolic and flavonoid compounds, which may have contributed to its antioxidant activity. Furthermore, the active fraction obtained from the bioautographic TLC and harvested using preparative TLC had stronger antioxidant activity against DPPH radicals (75.71 µg/mL) than the crude pigment extract. However, the ABTS radical-reducing activity was lower (226.59 µg/mL) than the crude pigment extract. The maximum wavelength of the pigment extract was 453 nm, indicating the presence of carotenoids. In addition, the lowest concentration of the crude pigment extract (50 µg/mL) and selected active fractions (18.75 µg/mL) increased yeast Schizosaccharomyces pombe ARC039 tolerance to oxidative stress and induced mitochondrial activity. Active fraction one extract analyzed using LC-MS/MS contained piceatannol, resveratrol, isorhapontigenin, isoliquiritigenin, liquiritin, and 2-Omethylisohemigossylic acid lactone, which may contribute to its antioxidant activity. Therefore, the yellow pigment extract and the active fraction produced by P. oryzihabitans SAB E-3 are potential candidates for natural antioxidant sources.

Phytochemical, proximate analysis and antioxidant activity of the rhizome of Alpinia nigra (Gaertn.) B.L. Burtt (Zingiberaceae) in Tamulpur district, Assam

The present research examines the chemical composition, proximate characteristics and antioxidant analysis of Alpinia nigra’s rhizome extract. Results of GC-MS analysis revealed a total of 22 volatile compounds of which Tris (tert-butyldimethylsilyloxy) arsane (2.89 %), 2-ethylthiolane, S, S-dioxide (3.47 %), Ambrial (6.68 %) and Silicic acid, diethyl bis (trimethylsilyl) ester (4.59 %) were the major compounds. The rhizome was found to have variable quantities of proximate compositions such as moisture content (55.5 %), ash content (4.72 %), crude fat (52 %), crude fibre (41.25 %), crude protein (28.95 µg/g), carbohydrate (46.27 %) and dry matter (33.4 %). The crude extraction of the rhizome was done by Soxhlet apparatus. The phytochemical screening showed the presence of alkaloid, tannin, terpenoid, glycoside, steroid, carbohydrate and a considerable amount of phenol and flavonoid. Phenolic and flavonoid content in the extracts was determined by the Folin-Ciocalteu and aluminium chloride assays as gallic acid equivalent and quercetin equivalent respectively. To evaluate the antioxidant activity of rhizome extract, phosphomolybdenum assay, ferric-reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) were used. The findings indicate that the rhizome extract is rich in phenol and flavonoid content and would serve as a promising source of natural antioxidants in the food, cosmetics and pharmaceutical industries.

Comparative studies of antioxidant activity and profile of some spices

Compounds that prevent or slow down the oxidation of lipids or other molecules like free radicals are known as antioxidants. The Study evaluated the antioxidant capacity, hydrogen peroxide scavenging capacity, and total flavonoid and phenol contents of six spices. Dried samples of spices were extracted in distilled water and analyzed using spectrophotometric and titrimetric methods. TAC results ranged from 232.79 - 64.32 mg/100g, with clove and black cardamom exhibiting the highest and lowest antioxidant activity respectively. The H2O2 scavenging activities result had clove and rosemary with the highest scavenging activity. Rosemary had the highest total phenol (5060 mg/100g) and flavonoid (1339 mg/100g) contents while black cardamom had the lowest values in both. Spices could be substituted for synthetic antioxidants in the food industry and as dietary sources of natural antioxidants.

GC-MS analysis of three Diospyros species and evaluation of its in vitro rat intestinal a-glucosidase and FRAP activity

Abstract. Hariyanto NA, Ramadhan R, Raharjo Y, Firdaus YFH, Kurnia IT, Lestari DA, Suwandari S, Mahmuda NF, Nathanael J, Phontree K, Phuwapraisirisan P, Riyadi L, Rahman A, Abdulgani N. 2024. GC-MS analysis of three Diospyros species and evaluation of its in vitro rat intestinal a-glucosidase and FRAP activity. Biodiversitas 25: 2442-2453. The vast diversity of natural products has long been recognized as a potentially valuable source of bioactive compounds derived from nature. The Diospyros species, belonging to the Ebenaceae family, thrive in tropical forest regions and have been traditionally used for treating various disorders such as ischemic stroke, hypertension, and infectious diseases. This research aims to assess the phytochemical constituents, rat intestinal a-glucosidase, and Ferric-Reducing Antioxidant Power (FRAP) of non-polar (n-hexane) and semi-polar (dichloromethane) extracts from three Diospyros species, i.e., Diospyros buxifolia (Blume) Hiern; Diospyros celebica Bakh.; Diospyros confertiflora (Hiern) Bakh). Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified numerous bioactive secondary metabolites in the extracts. The study revealed that the semi-polar extracts of D. buxifolia exhibited potent rat intestinal a-glucosidase inhibitory activities, with an IC50 value of 33.31±3.23 ug/mL. The IC50 of acarbose as a positive control was 6.31±0.31 ug/mL. The FRAP test demonstrated that the non-polar and semi-polar leaf extracts of the three Diospyros species from East Kalimantan are potential sources of natural antioxidants, with the IC50 in the range of 6.48±0.38 umol Fe/g - 11.35±0.16 umol Fe/g. The results of this study confirm the therapeutic properties of leaf extracts derived from 3 Diospyros species, which align with their traditional medicinal use.

Comparison the effect of plant extracts and antibiotics on gram negative bacteria isolated from patients with urinary tract infection in Tikrit city

Background: With increasing bacterial resistance for antibiotic, there is an increasing interest in medicinal herbal as a new source of an antimicrobial agents and with less side effects than conventional drugs. Objective: Was to evaluate the potential of Syzygium aromaticum and rosemarinus officinalis extract on Proteus mirabilis isolates in vitro. Methods: Six pathogenic gram negative bacilli belonging to three different genus (E.coli, Proteus mirabilis, and Enterobacter aerogenes) and two isolates from each species were used in this study and four concentration (100%, 75%, 50%, 25% mg/ml ) from each plant extracts (aqueous and ethanolic of Syzygium aromaticum and rosemarinus officinalis extracts ) were prepared to be antibacterial agent. antibacterial activity was measured by using wells method and five antibiotics using to compare with the activity of antibacterial agent. Results: The result of the study shown that the ethanolic extracts of Syzygium aromaticum is a strong antibacterial agent (with diameter of inhibition zone 25 mm) against Proteus mirabilis. Enterobacter aerogenes with (15mm) of inhibition zon, E.coli did not show any inhibition zone also the aqueous and ethanolic of rosemarinus officinalis extracts and aqueous of Syzygium aromaticum extracts did not show any activity towards any gram negative bacilli also the results of the study show resistance isolates of E.coli and Proteus mirabilis toward several antibiotic while Enterobacter aerogenes is sensitive for more antibiotics that used in this study. Conclusions: Our study concluded that the extract of Syzygium aromaticum has high potential as antibacterial agent against UTI that caused by Proteus mirabilis, clove (syzygium aromaticum) can be used in pharmaceutical for the production of new synthetic agents. There is an increasing interest in phytochemicals as new sources of natural antioxidant and antimicrobial agents. The natural compounds which have biological activities are interest to pharmaceutical industries especially for treatment of human disease of microbial origin and several pathological disorders such as cancergenesis, coronary atherosclerosis, as well as in ageing processes.

Antioxidant Properties and Antibacterial Activity of Breadfruit (Artocarpus altilis) Bark and Leaf Extract against Staphylococcus Aureus and Escherichia Coli

This study comprehensively investigated the antioxidant properties and antibacterial activity of breadfruit (Artocarpus altilis) bark and leaf extract against two common bacterial strains, Staphylococcus aureus, and Escherichia coli. The objective was to assess the potential therapeutic applications of breadfruit extract in combating bacterial infections caused by these organisms. The researchers employed an experimental research design, utilizing controlled experiments to evaluate the effects of breadfruit extract on the target bacteria. Both the bark and leaf parts of the breadfruit plant were examined in the study. The extracts were subjected to analysis to identify and quantify the presence of beneficial compounds. The analysis revealed the presence of various compounds, including but not limited to Phenolic Acid and Flavonoids, which are known for their potential health benefits and antioxidant properties. These compounds were found to be present in relatively high concentrations, suggesting the potential of breadfruit extract as a source of natural antioxidants. In terms of antibacterial activity, the breadfruit leaf extract exhibited promising results by demonstrating significant inhibitory effects against both Staphylococcus aureus and Escherichia coli. In contrast, the bark extract showed limited effectiveness against Escherichia coli but displayed some inhibitory activity against Staphylococcus aureus. These findings suggest that breadfruit extract may have potential as a natural antimicrobial agent, particularly in combating Staphylococcus aureus infections.

Using polyphenol-rich extracts from tropical fruit byproducts to control lipid and protein oxidation in cooked chicken models

AbstractThe present work aimed to analyse the bioactive compounds and antioxidant activities of peel and seed extracts obtained from three tropical fruits: papaya, mango, and loquat, with different solvents (water, ethanol, and water:ethanol, 1:1) and evaluate their potential effects as antioxidants in a cooked chicken model under refrigerated storage. In the seed and peel extracts produced, bioactive compounds (total phenolic compounds, total flavonoids, and condensed tannins) were quantified. Additionally, antioxidant activities (ABTS, DPPH, and FRAP) were assayed spectrophotometrically. Seed extracts from the three fruits were selected for application in a cooked chicken model in which colour, lipids, and protein oxidation were evaluated during refrigerated storage. Moreover, compared with the other extracts, the mango seed extracts (MSEs), irrespective of the extraction solvent used, had the highest contents of bioactive compounds and antioxidant activities. MSEs significantly reduced the CIE L* and increased the CIE a* while effectively controlling lipid and protein oxidation in cooked chicken models during refrigerated storage. Due to their high antioxidant activity and high concentration of phenolic compounds, flavonoids, and condensed tannins, MSEs are interesting sources of natural antioxidants and bioactive compounds for use in the meat industry.

An insight into the antioxidant activities and the exploration of record high quantities of quercetin and luteolin in the plant parts of Myxopyrum smilacifolium (wall.) Blume

This study attempts to reveal antioxidants in the plant parts of Myxopyrum smilacifolium (Wall.) Blume using antioxidant assays and LC-MS/MS analysis. Methanol is the most effective solvent for collecting antioxidants. The roots-derived methanol extract demonstrates the greatest antioxidant activity, corresponding to the extremely low IC50 values of 16.39 µg/mL and 19.80 µg/mL for DPPH and ABTS radicals, respectively. The high phenolic and flavonoid contents are the primary reason for outstanding total antioxidant capacity (TAC; i.e. 247.73 ± 1.62 mg GA/g or 163.93 ± 0.83 mg AS/g) of the root extract. LC-MS/MS quantification of five phenolic compounds reveals exceptionally high amounts of quercetin and luteolin in the root extract, ranging from 238.86 ± 5.74 to 310.99 ± 1.44 µg/g and from 201.49 ± 7.84 to 234.10 ± 2.54 µg/g, respectively, in the root-derived methanol extract. The achievement highlights M. smilacifolium as a promising source of natural antioxidants for large-scale medical applications.

Extraction, analysis of antioxidant activities and structural characteristics of flavonoids in fruits of Diospyros lotus L.

Flavonoid compounds are considered important components of new sources of natural antioxidants. This study was performed to optimize the ultrasound-assisted extraction processes of flavonoids from date plum persimmon (DPP) fruits, along with the in vitro antioxidant capacities and identities of those components. First, the effects of liquid/solid ratio, ethanol concentration, extraction time, and extraction temperature on flavonoid yields were investigated by independent variables analysis. Then the response surface methodology was used to optimize the extraction process, and the maximum flavonoid content was 3.05 ± 0.03 mg/g DW under the conditions of liquid/solid ratio 27:1 (mL/g), 74 mL ethanol/100 mL, extraction time 27 min, and extraction temperature 80 °C. Moreover, by DPPH and ABTS assays, the crude extracts of flavonoids in DPP fruits exhibited robust scavenging capacities with IC50 values of 1.76 and 0.82 μg/mL, respectively. In addition, 17 bioactive compounds of DPP were isolated and identified by HPLC-ESI-QTOF-MS/MS, among which two were phenolic acid derivatives, two were flavanones, eight were flavones, four were pentacyclic triterpenoids and one was xanthone. This study provided information regarding the phytochemical composition and functional properties of DPP fruits, supporting future research to facilitate the development and utilization of DPP as a functional food.