Rutin Equivalents Research Articles

Determination of total flavonoid content by aluminum chloride assay: A critical evaluation

Flavonoids are important natural bioactive compounds. Quantitation of total flavonoid content (TFC) is widely performed using the aluminum chloride colorimetric assay against a flavonoid standard assuming equal responses from all flavonoids. The aim of this work was to critically evaluate the assay employing spike recovery in plant extracts and three authentic flavonoid standards (catechin, quercetin, and rutin). Due to the inherent variations in absorbance values at quantitation wavelengths between investigated flavonoids, the assay produced huge unacceptable differences in TFC. For trials involving AlCl3 alone in standard solutions, false-positive results were obtained (63–124%) when quercetin content was expressed as rutin equivalents. Conversely, false-negative results were found (26–42%) when rutin concentration was expressed as quercetin equivalents. Similarly, unacceptable spike recoveries were recorded (8–106%) when involving AlCl3 alone in standard solutions at all investigated wavelengths. For plant extracts, unacceptable differences (58–152%) in TFC were also obtained when either quercetin or rutin was used as a quantitation standard. When AlCl3 is used in conjunction with sodium nitrite, unacceptable high or low recoveries were noted depending on the quantitation standard used. The findings of this work provide conclusive evidence highlighting conceptual and methodological flaws in the AlCl3 colorimetric assay for the determination of TFC.

Qualitative and Quantitative Phytochemical Screening of Bitter and Neem Leaves and their Potential as Antimicrobial Growth Promoter in Poultry Feed

Gastrointestinal health challenges without in-feed antibiotics are a crucial concern to poultry farmers. Although, quite a few substitutes for antibiotics have emerged, phytogenics and antibiotic properties of medicinal plants cannot be overlooked with regard to control, good health and minimizing sub – clinical bacteria-induced infections by zoonotic enteropathogenic bacteria in poultry birds. Vernonia amygdalina (Bitter leaf) and Azadirachta indica (Neem) leaves were collected early in the morning and oven dried to 15% moisture content. The non-essential oil was obtained by cold maceration method using methanol. Appropriate methods were used for the qualitative and quantitative analysis of phytochemicals in the respective oils. Qualitative analysis of phytochemicals showed that, saponins and terpenoids were highly detected (+++) in V. amygdalina. Saponins and terpenoids were slightly detected (+) in A. indica. Phenolic compounds were highly detected (+++) in both plants. Flavonoids were also identified (++) in both plants, but tannins were highly detected (+++) in A. indica. Quantitative analysis revealed a rather high concentration of complete phenolic content and overall flavonoid content in V. amygdalina. Total phenolic content of 44.76 mg Gallic acid equivalent / g of extract and 57.21 mg Rutin equivalent / g of extract (total flavonoid content) was recorded in V. amygdalina and 25.77 mg Gallic acid equivalent / g of extract (total phenolic content) and 24.45 mg Rutin equivalent /g of extract (total flavonoid content) in A. indica.
 In conclusion, both plant extracts exhibited possibility as suitable substitutes to proprietary antibiotics that can be beneficial to gastrointestinal health and overall performance in animal nutrition.

Characterization of allelochemicals from Pistia stratiotes extracts and their effects on the growth and physiology of Microcystis aeruginosa.

Due to the public and environmental health impact of cyanotoxins, investigations have been focused on finding environmental friendly algaecides from aquatic plants. The present study had the objective to evaluate the population control and physiological response of Microcystis aeruginosa (Kützing) Kützing (strain BCCUSP232) exposed to Pistia stratiotes L. extracts. Aqueous and ethanolic extracts of P. stratiotes at different concentrations (10, 25, and 50 mg L-1) were submitted to M. aeruginosa and reduced significantly (p<0.05) the cyanobacterium cell density. The ethanolic extract presented the greatest growth inhibition of the strain at the highest concentration. During exposure to P. stratiotes extracts, intracellular hydrogen peroxide levels, malondialdehyde content, and antioxidant enzymes (peroxidase, catalase, and glutathione S-transferase) activities increased in M. aeruginosa, while total protein concentration decreased when compared to the control group. Superoxide dismutase (SOD) activities presented a sharp decline, suggesting superoxide radical and peroxide accumulation. This implied that SOD was a target for bioactive substance(s) from aqueous and ethanolic extracts of P. stratiotes. Phytochemical screening of the extracts revealed that the ethanolic extract presented 93.36 mg gallic acid equivalent (GAE) per gram dry weight (g-1 DW) total polyphenols and 217.33 mg rutin equivalent (RE) per gram dry weight total flavonoids, and for the aqueous extract, 5.19 mg GAE g-1 DW total polyphenols and 11.02 mg RE g-1 DW total flavonoids were detected. Gas chromatography (GC)/mass spectrometry (MS) analyses of the ethanolic and aqueous extracts presented palmitic acid ethyl ester as major allelochemical. In view of these results, it can be concluded that P. stratiotes showed potential in controlling M. aeruginosa populations.

Anticoagulant potential and total phenolic content of six species of the genus Ficus from Azad Kashmir, Pakistan

Purpose: To investigate the total phenolic and flavonoid contents of Ficus benghalensis, Ficus elasticaa, Ficus palmata, Ficus religiosa, Ficus semicordata and Ficus auriculata, and to determine their anticoagulant potential.&#x0D; Methods: Crude methanol extracts were prepared from the plant leaves, and fractionated using liquidliquid partition with n-hexane, chloroform and ethyl acetate. The total flavonoid and total phenolic contents of the extracts and their fractions were determined. The anticoagulant potential of the six Ficus species were evaluated in healthy human plasma, using activated partial thromboplastin time (APTT) and prothrombin time (PT) methods.&#x0D; Results: Phytochemical analysis showed the presence of considerable amounts of flavonoids ranging from 5.3 ± 0.7 to 11.8 ± 0.3 mg rutin equivalents (RE)/g, and phenolic compounds ranging from 8.0 ± 0.7 to 86.5 ± 1.5 mg gallic acid equivalents (GAE)/g in each fraction of the six species. Results from in vitro anticoagulant potential assays showed significant anticoagulant properties, with prothrombin time (PT) ranging from 17.7 ± 0.7 to 26.7 ± 2.2 s, and activated partial thromboplastin time (APTT) varying from 47.7 ± 3.3 to 72.3 ± 5.4 s.&#x0D; Conclusion: The results indicate that F. semicordata and F. Religiosa have higher anticoagulant potential than the other Ficus species studied.

Low pungency and phytochemicals relationship during bulb assessment in the sweet onion breeding program

This work reports the results of a four-year Italian breeding program carried out over five locations, for the selection of low pungency onion genotypes. The performances of new Italian open-pollinated (OP) lines were compared to both pungent and non-pungent commercial varieties. Pungency level was evaluated on each single bulb as pyruvic acid concentration, together with other related quality traits, namely soluble sugars (SSR), total phenols (TPC) and flavonols (TFC). All OP lines were classified as low to medium pungent onions, and only the lines 09/12, 14/12 and 15/12 slightly exceeded the limit of 3 mmol/kg for the low pungency. In the first two years of selection, OP lines showed a general decrease in pyruvic acid concentration (from 16 to 67%) in the second year, while on average SSR did not significantly change and phenolics increased. SSR appeared positively correlated with pyruvic acid concentration, TPC and TFC. A marked effect of the environmental conditions was observed over the different years and locations of experiment. Overall, 13/12 OP line distinguished for the highest reduction of pyruvic concentration, which averaged 3.0 mmol/kg, while maintaining a high level of SSR (6.6 °Brix), TPC and TFC (1.78 and 0.49 mM gallic and rutin equivalents, respectively).

Chemical composition, biological properties and bioinformatics analysis of two Caesalpina species: A new light in the road from nature to pharmacy shelf

Caesalpinia bonduc and C. decapeleta var. japonica have great importance in traditional medicine systems but scientific information’s are still lacking for their potentials. To explore their bioactivity, we assessed the antioxidant, enzyme inhibitory abilities of the dichloromethane (DCM), ethyl acetate, methanol, and water extracts prepared from the leaves and bark. The cytotoxicity and anticancer properties of the extracts were also assessed in vitro. The water extract of C. decapeleta leaves possessed highest phenolic content (108.16 mg gallic acid equivalent (GAE)/g extract), while the highest flavonoid content was recorded for the C. bonduc leaf methanolic extract (27.89 mg rutin equivalent (RE)/g extract). In general, C. decapeleta extracts possessed higher radical scavenging potential compared to C. bonduc extracts. C. decapeleta DCM leaves extract (10.20 mg galantamine equivalent (GALAE)/g extract) showed highest inhibition against butyrylcholinesterase. The cytotoxicity of the most potent methanolic and aqueous extracts were assessed against four cell lines. The chemical profiles of both species appeared to be different. C. bonduc was abundant in organic and phenolic acids as well as their esters. Flavonoid glycosides, bonducellin and its derivatives and caesalminaxins were identified. Whereas, C. decalpetala possessed many galloylated compounds. The cytotoxicity of C. bonduc and C. decapetala extracts was tested using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based assay on VERO (kidney of an adult African Green monkey cells), HeLa (human cervical adenocarcinoma cells), RKO (human colon carcinoma cells), FaDu (human hypopharyngeal squamous carcinoma cells) cell lines. C. bonduc bark water extract exhibited the highest cytotoxicity towards HeLa (50 % cytotoxic concentration (CC50): 28.5 μg/mL) cancer cell line, as compared to normal VERO cells (CC50:35.87 μg/mL). For C. decapetala, the highest cytotoxicity was found for bark methanol extract on the HeLa cells with CC50 of 46.08 μg/mL and selectivity index of 3.33. In the gene ontology analysis, prostate cancer, nuclear factor kappa B (NF-kappa B) signaling, proteoglycans in cancer pathways might support the results of the cytotoxic assays. These results showed that the tested Caesalpinia species, showing potent inhibitory action against butyrylcholinesterase, might represent novel phytotherapeutic avenues for the management of Alzheimer’s disease.

Annulohypoxylon sp. strain MUS1, an endophytic fungus isolated from Taxus wallichiana Zucc., produces taxol and other bioactive metabolites.

The online version contains supplementary material available at 10.1007/s13205-021-02693-z.

Preliminary Investigation of the Antioxidant, Anti-Diabetic, and Anti-Inflammatory Activity of Enteromorpha intestinalis Extracts

Marine algae are a promising source of potent bioactive agents against oxidative stress, diabetes, and inflammation. However, the possible therapeutic effects of many algal metabolites have not been exploited yet. In this regard, we explored the therapeutic potential of Enteromorpha intestinalis extracts obtained from methanol, ethanol, and hexane, in contrasting oxidative stress. The total phenolic (TPC) and flavonoids (TFC) content were quantified in all extracts, with ethanol yielding the best values (about 60 and 625 mg of gallic acid and rutin equivalents per gram of extract, respectively). Their antioxidant potential was also assessed through DPPH•, hydroxyl radical, hydrogen peroxide, and superoxide anion scavenging assays, showing a concentration-dependent activity which was greater in the extracts from protic and more polar solvents. The α-amylase and α-glucosidase activities were estimated for checking the antidiabetic capacity, with IC50 values of about 3.8 µg/mL for the methanolic extract, almost as low as those obtained with acarbose (about 2.8 and 3.3 µg/mL, respectively). The same extract also showed remarkable anti-inflammatory effect, as determined by hemolysis, protein denaturation, proteinase and lipoxygenase activity assays, with respectable IC50 values (about 11, 4, 6, and 5 µg/mL, respectively), also in comparison to commercially used drugs, such as acetylsalicylic acid.

Application of response surface methodology to optimize the ultrasound-assisted flavonoid-rich extraction of fish mint (Houttuynia cordata Thunb.)

Introduction: Fish mint (Houttuynia cordata Thunb.) has been widely used in both traditional and modern medicine for a long time. Its flavonoid component has a variety of pharmacological effects that have been demonstrated in previous studies. In this research, we optimized the ultrasoundassisted extraction (UAE) of flavonoid-rich content from Houttuynia cordata Thunb. using response surface methodology - central composite design (RSM-CCD). Methods: Based on the results of single-factor test , central composite design (CCD) approach-based response surface methodology (RSM) analysis was utilized to evaluate the effects of ethanol concentration, solid-liquid ratio, extraction time, and temperature on the total flavonoid content expressed as rutin equivalents. Flavonoid component from the extract under optimum conditions was then identified by using UPLC-ESI-MS. Results: The optimum conditions for obtaining the maximum TFC (53.6321 +/- 0.9474 mg RE/g) were found at 80% ethanol concentration, 1/60 g/mL solid-liquid ratio for 38 min at 60 oC. Using UPLC-ESI-MS, we determined six major flavonoid compounds in the extract: rutin, hyperin, isoquercitrin, quercitrin, afzelin, and quercetin. Conclusion: From these results, this study showed that UAE is a fast and efficient technique for flavonoids extraction from the fish mint.

Antioxidant, Anti-tyrosinase, Anti-α-amylase, and Cytotoxic Potentials of the Invasive Weed Andropogon virginicus.

Andropogon virginicus is an invasive weed that seriously threatens agricultural production and economics worldwide. In this research, dried aerial parts of A. virginicus were extracted, applying Soxhlet and liquid-liquid phase methods to acquire the total crude (T-Anvi), hexane (H-Anvi), ethyl acetate (E-Anvi), butanol (B-Anvi), and water (W-Anvi) extracts, respectively. In which, T-Anvi contains the highest total phenolic and flavonoid contents (24.80 mg gallic acid and 37.40 mg rutin equivalents per g dry weight, respectively). Via anti-radical (ABTS and DPPH), and reducing power assays, E-Anvi exhibits the most potent activities (IC50 = 13.96, 43.59 and 124.11 µg/mL, respectively), stronger than butylated hydroxytoluene (BHT), a standard antioxidant, while the lipid peroxidation inhibitory effect of E-Anvi (LPI = 90.85% at the concentration of 500 µg/mL) is close to BHT. E-Anvi shows the most substantial inhibition (IC50 = 2.58 mg/mL) on tyrosinase. Notably, α-amylase is significantly suppressed by H-Anvi (IC50 = 0.72 mg/mL), over twice stronger than the positive control, palmitic acid. In the cytotoxic assay, E-Anvi is the strongest extract inhibiting K562 cells (IC50 = 112.01 µg/mL). Meanwhile, T-Anvi shows the highest prevention on Meg-01 expansion (IC50 = 91.40 µg/mL). Dominant compounds detected in E-Anvi by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) are identified as flavonoids. However, among four major compounds identified in H-Anvi by gas chromatography-mass spectrometry (GC-MS), palmitic acid and phytol are the most abundant compounds with peak areas of 27.97% and 16.42%, respectively. In essence, this is the first report describing that A. virginicus is a potential natural source of antioxidants, tyrosinase and α-amylase inhibitors, and anti-chronic myeloid leukemia (CML) agents which may be useful in future therapeutics as promising alternative medicines.

Changes in the biochemical compounds of Vacciniummyrtillus, Vacciniumvitis-idaea, and forest litter collected from various forest types

The aim of this study was to evaluate the impact of forest clear-cutting on the phenolic compounds and antiradical activity of Vaccinium myrtillus, Vaccinium vitis-idaea, and forest litter collected during the vegetation stages in 2 forests types (Pinetum vacciniosumand Pinetum vaccinio-myrtillosum). The Folin-Ciocalteu method, aluminum trichloride colorimetric assay, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) test were applied to perform the total phenolic content (TPC), total flavonoid content (TFC), and antiradical activity analyses of the extracts of the underground and aboveground parts of the plants and forest litter. The TPC content varied from 35.87 to 229.76 mg/g (expressed as rutin equivalents) and 120.03 to 309.64 mg/g in the aboveground extracts of V. myrtillus and V. vitis-idaea, respectively. Remarkably lower amounts of phenolic compounds were determined in the underground extracts of the tested shrubs. The TPC content in the forest litter ranged from 3.12 to 11.89 mg/g. The radical scavenging activity (RSA) varied from 3.12 to 434.68 mg/g; the lowest antiradical activity was determined in the underground extracts, while the highest was in the aboveground extracts of V. myrtillus. The TFC was dependent on the vegetation phase, forest type, and clear-cutting, and varied from 7.97 to 40.18 mg/g in the aboveground extracts of the tested plants. Flavonoids were not detected in the underground extracts of the samples or in the forest litter. The chemometric analysis revealed statistically significant trends of environmental impact on V. myrtillus and V. vitis-idaea at the different vegetation stages. Hypotheses testing showed that the TPC, TFC and RSA expressed statistically significant (α ≤ 0.05) changes in 68%, 60% and 71% of the tested samples after clear-cutting, respectively.

Antioxidant Activities of Methanol Extracts of Thirteen Cameroonian Antibacterial Dietary Plants

This study falls within the search for alternative solutions to problems related to diseases associated with oxidative stress. It involved the evaluation of antioxidant activities extracts from thirteen antibacterial Cameroonian food plants, namely, P. nigrum, A. cruentus, L. sativa, S. edule, S. nigrum, V. amygdalina, A. hybridus, V. hymenolepis, L. capensis, M. esculenta, C. melo, T. occidentalis, and T. triangulare. The thirteen plant extracts with a broad spectrum of antibacterial activity all showed total reducing powers ranging between 2.41 and 27.81 AAE (mg ascorbic acid equivalents per gram of dried extract) and total phenol contents between 2.65 and 35.03 GAE (mg of gallic acid equivalents per gram of dried extract) of dry extract. Except for extracts of L. capensis, the other 12 extracts showed flavonoid contents ranging between 0.29 and 5.99 RE (rutin equivalents per gram of dried extract). All 13 plant extracts also showed free radical scavenging activity against DPPH· with IC50 ranging between 1.65 and 310.52 μg/ml, while 12 of these extracts exhibited inhibitory activity against NO· radical (IC50 ranging from 19.77 to 157.72 μg/ml). Statistically insignificant positive correlations (p&gt;0.5) were found between antibacterial activities of these plants and their antioxidant activities. The different results of this study provide scientific evidence for the use of these antibacterial food plants in the control of different conditions associated with oxidative stress.

Assessment of In Vitro Antioxidant and Anti-Inflammatory Potentials of Methanol Extract of Chrysophyllum albidum Cotyledon

Background: This study was aimed at analysing the phytochemicals in Chrysophyllum albidum cotyledon extract and their in vitro antioxidant and anti-inflammatory effects. Methods: The Chrysophyllum albidum cotyledon methanol extract (CCME) was phytochemically screened, and flavonoids and phenol contents, antioxidant and anti-inflammatory assays were carried out on the extract using standard procedures. Results: Phytochemicals analysis revealed the presence of steroids, tannins, flavonoid, saponin, triterpenes and xanthoproteins. The phenolic concentration, total flavonoids concentration and sugar concentration were found to be 26.720.048 μg of Tannic Acid Equivalent (TAE /mg, 23.121.92 μg of Rutin Equivalent (RTE)/mg (10.491.12 μg of Quercetin Equivalent (QE)/mg) and 778.3812.82 μg of glucose/ml respectively. The extract demonstrated significant (P&lt;0.05) inhibitory effect compared with the standards as potent antioxidant with DPPH IC50 of 550.52 ± 82.83 μg/ml, lipid peroxidation (45.85 % – 65.85 %), Ferric reducing power showed linear correlation to the standard and the anti-inflammatory potential with (22.06 % – 26.37 %) percentage protection of the human red blood membrane stability and the percentage inhibition of denaturation of albumin (3.42 % – 7.32 %). Conclusion: The study showed that C. albidum cotyledon methanol extract is a potent antioxidant and anti-inflammatory agent to oxidative stress and pathological disease caused by reactive species.

Effect of grape pomace on some biological assays of experimental rat

This study is carried out to reduce the environmental impact of grape proceeding wastes through study the effect of the grape pomace (GP) utilization on some biological parameters which reflect the health status of rats fed on high fat diets. It was carried out via an experimental biological study, where adult healthy male albino rats, weighing 1855g, were fed on high-fat diets supplemented with 5, 10, and 15% of GP. The proceeding results showed that the protein amount in GP was up to 8.75%, lipids content was 7.38% and the total dietary fiber was 46.63%. K, Mg, Ca, Na, P and S were found in higher concentrations. The lipids of GP contained 85.75% unsaturated fatty acids (19.14% monounsaturated and 66.60% polyunsaturated fatty acid).The predominant fatty acid was linoleic acid (65.29%). Total phenolic (TP) compounds (expressed as mg gallic acid equivalent (GAE) per g sample) were about 50.35mg GAE/g, total flavonoids (expressed as mg rutin equivalent (RE) per g sample) were 22.25 mg RE/g and the DPPH radical scavenging activity was 51.92%. Gallic acid was the most abundant polyphenols, (9.76 mg/100g). Catechin was the most abundant flavonoid compound (52.5 mg/100g). Resveratrol as stilbenes content was 14.11 mg/100g. Supplementation of the high-fat diet with GP resulted in a significant reduction in cholesterol, triglycerides, LDL-C and vLDL-C levels of the tested rat groups. Treated rats had higher mean values of HDL-C than that fed on HFD only. The best result for estimation of specific studied parameters (AST, ALT, urea, uric acid and creatinine) revealed that the rat groups fed on the high fat diet containing 15% GP was the healthiest. It was found that a non-significant alteration in the levels of AST, ALT, uric acid and creatinine, compared with the negative control rat group was detected. Consequently, it could be concluded that GP could be considered as a source of healthy compounds that could be applied in animal feed, pharmaceutical, cosmetic or food industries.

Ultrasound assisted extraction of phytochemicals from Coccinia indica fruits and its characterization

Ultrasound assisted extraction (UAE) technique was employed for the extraction of phytochemicals from Coccinia indica fruit. Twenty-two compounds were identified post extraction process by GCMS analysis. Temperature, time of extraction, solvent concentration and solid-solvent (SS) ratio were considered as important process parameters for UAE. Response surface method was applied for optimizing the extraction process. The study focussed on the yield of extract, antioxidant activity (DPPH and ABTS), total phenolic content and total flavonoid content as the dependent variables. The optimum values of process parameters were obtained to be 30 °C temperature, 42 min of extraction time, 63% solvent (ethanol) concentration and SS ratio of 1:60. At these optimum conditions, the extract yield was 18.58%. The DPPH activity of 83.42%, 27.18% ABTS radical scavenging ability, 12.82 mg Gallic acid equivalent (GAE)/g of phenolic content and 79.81 mg Rutin equivalent (RE)/g of flavonoid content were obtained. Major compounds identified by GCMS were rutin, naringenin, apigenin and kaempferol. Resveratrol was also identified in the extract of C. indica fruits.

Antioxidant and anti-inflammatory activities of phenolic compounds extracted from lemon myrtle (Backhousia citriodora) leaves at various extraction conditions.

Lemon myrtle leaves were extracted with ethanol at different temperatures (25, 50, and 80°C) and times (2, 4, 6, and 10h) to examine the effect of extraction conditions on total polyphenol contents (TPC), total flavonoid contents (TFC), their antioxidant, anti-inflammatory activities, and amount of phenolic compounds. Under optimal extraction conditions (80°C and 6h), the values were 23.37%, 102.72mg gallic acid equivalents (GAE/g dry basis), 23.37mg rutin equivalents (RE/g dry basis), 83.31%, 60.13%, and 1.10% for yield, TPC, TFC, DPPH, ABTS radical scavenging activity, and reducing power, respectively. In addition, total amount of the phenolic compounds of extract was determined as 43.9μg/g. The anti-inflammatory effect was determined in lipopolysaccharide-stimulated RAW 264.7 cells and inhibited the production of inflammatory mediators such as nitric oxide (NO). These results indicate that extracts of lemon myrtle leaves have potential as a valuable natural product with antioxidant and anti-inflammatory.

Assessment of flavonoids and phenolic compound accumulation in invasive Solidago canadensis L. in Slovakia

Solidago canadensis L. was introduced to Europe as an ornamental plant from North America in 1645 and began to spread during the XIX-XX centuries. Nowadays the species is considered the most aggressive invasive species. On the other hand, S. canadensis is considered to be a medicinal plant. The raw material known as Herba Solidaginis includes herbs of S. canadensis, S. gigantea, and S. virgaurea. These species are known for their diuretic, anti-inflammatory, antimicrobial, antioxidant, antispasmodic properties. The purpose of our study was to analyze the chemical compounds and some biological properties of S. canadensis, growing in Slovakia, to evaluate its therapeutic potential. The total phenolic content (TPC) of the extracts from aerial parts of S. canadensis was determined by the Folin-Ciocalteu method. The evaluation of total flavonoid content (TFC) was performed by using a spectrophotometric method. The flavonoids content was expressed as rutin equivalents (mg REs) per g DW vegetal product. The phytochemical profile of S. canadensis extracts was assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The radical scavenging activity of samples was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Reducing power of extracts was determined by the phosphomolybdenum method. Total phenolic contents (TPC) and total flavonoid contents (TFC) of the extracts varied from 204.19 to 293.43 mg GAE.g-1 DW, and 64.99 – 175.25 g QE.g-1 DW, respectively; the best results were obtained for ethanol extract. Some phenolic compounds were identified by HPLC with significant amounts of rutin (211.20 µg.mL-1), quercetin (122.08 µg.mL-1), quercitrin (102.50 µg.mL-1) and chlorogenic acid (147.00 µg.mL-1). The DPPH values in the inflorescences were higher than in the leaves: the antioxidant activity of leaf extracts was in the range from 5.34 to 17.16 mg TE.g-1, for inflorescences, this parameter ranged from 6.09 to 19.87 mg TE.g-1. The high total phenolic compounds and flavonoids can be used as a valuable source of phytochemicals in herbal remedies. Our study of S. canadensis, growing in Slovakia, shows the promising potential that can be evaluated as an effective antioxidant and antimicrobial agent in herbal medicines.

Insights into effectiveness of tight ultrafiltration and frozen storage in bioactive compound retention in watermelon juice concentrate

AbstractThe aim of this study is to evaluate the potential of tight ultrafiltration for the concentration of bioactive compounds in watermelon juice and also analyze the effectiveness of frozen storage for storing the juice concentrate. The concentration of the juice was performed at two different temperatures of 30 ± 2°C and 23 ± 2°C and at pressures of 2 and 3 bar for concentration factors of 1.5, 2, and 3. Total phenolic content in the concentrate was determined in terms of gallic acid and flavonoid concentration was analyzed in terms of rutin equivalent. Lycopene was determined spectrophotometrically using the hexane extraction method. The ultrafiltration (UF) process was successful in retaining a high percentage of bioactive compounds in the watermelon juice concentrate. Flavonoids showed the highest levels of concentration among the four important bioactive compounds. The ultrafiltration experimental set of T = 23 ± 2°C, P = 3 bar and volumetric concentration factor = 1.5 was found to be most feasible. Frozen storage at −18°C was successful in retaining a high percentage of bioactives in the concentrate after 1 month although vitamin C loss was on the higher side. Lycopene was highly preserved in the concentrate juice after frozen storage with retention of 93%.Practical ApplicationsOne of the major ways to reduce the amount of postharvest losses in watermelon is to convert it to juice by postharvest value addition. To make it available all through the year, the juice has to be processed in order to store it for longer periods. Membrane technology provides the best option to treat the juice in a nonthermal manner to retain its nutritional and sensorial characteristics after processing. Tight ultrafiltration can be a great tool for obtaining a juice concentrate that is rich in bioactive compounds. Watermelon has a significant amount of vitamin C, polyphenols, and also contains lycopene, a carotenoid with potential cancer preventive properties. Tight ultrafiltration can be useful in retaining these important components in the concentrated juice simultaneously reducing the water content, thereby increasing its shelf life. By optimizing different parameters associated with ultrafiltration, it can be possible to industrially scale up this process to make the juice available throughout the year.

Phenolics from Scorzonera tomentosa L.: Exploring the potential use in industrial applications via an integrated approach

Scorzonera tomentosa L. (family Asteraceae), endemic to Turkey is reputed for its medicinal attributes in the folkloric medicine. However, only few studies on the chemical composition and pharmacological properties of this plant have been published so far. In this direction, this study aimed to shed light on the phenolic composition, antioxidant and key enzyme inhibitory properties of S. tomentosa aerial parts and roots extracts prepared using different solvents (dichloromethane, ethyl acetate, hexane, water and methanol). Overall, the methanolic extracts and the infusion of both plant parts were better sources of total polyphenolics with 40.33 and 39.30 mg gallic acid equivalent (GAE)/g, respectively, while for the aerial parts, 22.42 and 21.84 mg GAE/g were measured for methanolic extract and root infusion, respectively. Extracts of the aerial parts showed considerable amount of total flavonoid content (2.96–34.93 mg rutin equivalent (RE)/g) as compared with the root extract (0.40–2.65 mg RE/g), with highest content observed in methanolic extract. For this reason, the methanolic extract of roots and aerial parts were subjected to liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-MSn) analysis. The methanolic and aqueous extracts of both plant parts proved to be most significant radical quenchers (1.05–45.89 mg trolox equivalent (TE)/g in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; and 1.82–82.94 mg TE/g in 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay) and reducing agents (39.40–164.06 mg TE/g in cupric reducing antioxidant capacity (CUPRAC) and 15.54–79.78 mg TE/g in ferric reducing antioxidant power (FRAP)). The dichloromethane extracts were significant metal chelators (13.92 and 6.24 mg ethylenediaminetetraacetate equivalent (EDTAE)/g for aerial parts and roots). Extracts of both plant parts showed selective inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Notable anti-tyrosinase activity was observed for all the extracts (aerial part: 16.40 ± 1.30 - 64.83 ± 0.28 and roots: 6.29 ± 0.50–65.46 ± 0.31 mg kojic acid equivalent (KAE)/g), while modest inhibitory activity against α-amylase (0.08−0.61 mmol acarbose equivalent (ACAE)/g) and α-glucosidase (0.09−0.83 mmol ACAE/g) for all the tested extracts. In addition, to provide the first scientific insight on the biological and chemical profile of S. tomentosa, observations from this present study tend to identify this plant as a valuable source of biologically active molecules for possible phytopharmaceutical and cosmeceuticals exploitation.

Comparative conventional extraction methods of ethanolic extracts of Clinacanthus nutans leaves on antioxidant activity and toxicity

PurposeThe purpose of this paper is to evaluate the antioxidant activity and toxicity of Clinacanthus nutans leaves from three conventional extraction methods, i.e. maceration, Soxhlet and magnetic stirring.Design/methodology/approachTotal flavonoid content (TFC) and phenolic content (TPC) were determined using colorimetric method of aluminum chloride and Folin-Ciocalteu (FC) assay, respectively. Antioxidant property of C. nutans was evaluated using 2,2'-diphenyl-1-pierylhydrazyl (DPPH) free radical scavenging assay. Cytotoxic activity of C. nutans against brine shrimp was evaluated based on LC50 (lethality concentration) after 24 h exposure to the plant extract.FindingsThe highest TPC of C. nutans was observed with Soxhlet extraction method (98.87 ± 10.43 mg of gallic acid equivalents (GAE/g) followed by maceration (68.77 ± 2.45 mg of GAE/g) and magnetic stirring (46.75 ± 2.45 mg of GAE/g). Interestingly, remarkable highest TFC was observed with magnetic stirring (568.90 ± 4.85 mg of rutin equivalent (RE)/g) followed by maceration (249.60 ± 2.79 mg of RE/g) and Soxhlet (174.8 ± 1.74 mg of RE/g). On the other hands, the extract obtained using maceration method showed the highest antioxidant activity (IC50: 14.18 mg/mL compared to ascorbic acid 144.36 µg/mL). Cytotoxicity of C. nutans from all extraction methods showed similar LC50 values with maceration (3.81 mg/mL), Soxhlet (2.61 mg/mL) and magnetic stirring (4.56 mg/mL), respectively.Originality/valueBoth phenolic and flavonoids are responsible for the antioxidant activity, of C. nutans extracts. Based on Meyer's toxicity index, all extracts were nontoxic (LC50>1 mg/mL).