Phenolic Composition Of Extracts Research Articles

Effect of simulated in vitro upper gut digestion of processed cowpea beans on phenolic composition, antioxidant properties and cellular protection

The effect of simulated in vitro upper gut digestion on the phenolic composition and antioxidant properties of processed cowpea beans was studied. The samples comprised four cowpea cultivars: a cream, brownish-cream and two reddish-brown cultivars. Dry cowpea seeds were soaked in water, blended into paste and deep-fried in vegetable oil. The fried samples were taken through in vitro upper gut digestion followed by freeze-drying of the supernatant. Phenolic composition of extracts from the supernatants were determined using HPLC-MS. Radical scavenging activities were documented using the TEAC, ORAC and nitric oxide (NO) assays. In vitro digestion of the processed cowpeas resulted in phenolic-peptide complexes that were identified for the first time, and decreased extractable phenolic compounds. However, the radical scavenging activities increased. The processed cowpeas and their digests inhibited cellular NO production, and oxidative DNA and cellular damage. In conclusion, deep-fried cowpeas when consumed, could potentially help alleviate oxidative stress-related conditions.

Comprehensive two-dimensional temperature-responsive × reversed phase liquid chromatography for the analysis of wine phenolics

Phenolic compounds are an interesting class of natural products because of their proposed contribution to health benefits of foods and beverages and as a bio-source of organic (aromatic) building blocks. Phenolic extracts from natural products are often highly complex and contain compounds covering a broad range in molecular properties. While many 1D-LC and mass spectrometric approaches have been proposed for the analysis of phenolics, this complexity inevitably leads to challenging identification and purification. New insights into the composition of phenolic extracts can be obtained through online comprehensive two-dimensional liquid chromatography (LC × LC) coupled to photodiode array and mass spectrometric detection. However, several practical hurdles must be overcome to achieve high peak capacities and to obtain robust methods with this technique. In many LC × LC configurations, refocusing of analytes at the head of the 2D column is hindered by the high eluotropic strength of the solvent transferred from the 1D to the 2D, leading to peak breakthrough or broadening. LC × LC combinations whereby a purely aqueous mobile phase is used in the 1D and RPLC is used in the 2D are unaffected by these phenomena, leading to more robust methods. In this contribution, the combination of temperature-responsive liquid chromatography (TRLC) with RPLC is used for the first time for the analysis of phenolic extracts of natural origin to illustrate the potential of this alternative combination for natural product analyses. The possibilities of the combination are investigated through analysis of wine extracts by TRLC × RPLC-DAD and TRLC × RPLC-ESI-MS.

The influence of extraction method on the composition and analgesic activity of Calligonum comosum phenolic extracts

Abstract The aim of this study was to evaluate the analgesic activity and the effect of extraction methods (ultra-sound: UM and maceration: MM) and solvents (ethanol: EtOH and methanol: MeOH) on the composition of phenolic extracts from Calligonum comosum. The results obtained by HPLC analysis demonstrated that the ethanol extracts have shown the highest content of total phenolic and flavonoid compounds. Also, the presence of most known phenolic compounds has been identified in all extracts, especially in the MeOH UM extract. The HPLC analysis showed the presence of ascorbic acid in methanol extracts and caffeic acid in ethanol extracts, and the maceration method shows a high concentration of phenolic compounds, the vanillin was detected in MeOH UM and the appearance of chlorogenic acid in UM extracts, finally the emergence of gallic acid, quercetin and rutin in some extracts. According to the results of the analgesic power, the methanolic extract of the maceration method induces a significant decrease in abdominal cramps compared to the control group and the values obtained are very close from those obtained with the standard anti-inflammatory drug (indomethacin). This result confirmed the beneficial effect of this Saharan plant.

Antioxidant potential and phenolic composition of extracts from Stachys tmolea: An endemic plant from Turkey

This study aims to screen bioactive compounds from Stachys tmolea an endemic plant from Turkey. The phenolic composition of the aerial parts of S. tmolea was investigated using methanol and water as solvents. Furthermore, the total antioxidant, radical scavenging, reducing power, and metal chelating activities of S. tmolea extracts were determined. Results show that S. tmolea is endowed with phenolic compounds with considerable antioxidant properties. Twenty compounds were identified and quantified in different extracts. Methanol was shown to be the most effective for the extraction of phytochemicals. The major compounds identified in the methanolic extract S. tmolea were verbascoside (3169.81 ± 14.38 μg/g dry plant), chlorogenic acid (1120.14 ± 41.24 μg/g dry plant), and apigenin 7-glucoside (146.46 ± 9.88 μg/g dry plant). Nevertheless, the antioxidant activities tested with different methods revealed no significant differences between aqueous and methanolic extracts. The current finding confirmed the importance of S. tmolea and Stachys genus in general which is used traditionally as mountain tea in Turkey and Iraq. Thus, further investigations should be done for the isolation and purification of bioactive molecules for both medicinal and industrial uses.

Composition of phenolic compounds in wild apple with multiple resistance mechanisms against postharvest blue mold decay

Several wild apple accessions (Malus sieversii) from Kazakhstan and two (Malus×soulardii, Malus sylvestris) from other parts of the world are highly resistant to blue mold decay caused by Penicillium expansum. Previous studies on the wound responses of these apples to infection by this fungus suggest multiple mechanisms of resistance including innate immunity. In this study, the phenolic composition of extracts from mature wild apples resistant (GMAL 4317.f, PI 589391, and PI 369855) and susceptible (GMAL 3623.i) to blue mold, as well as the susceptible cultivar ‘Golden Delicious’ (Malus×domestica) were investigated using ultra-high-performance liquid chromatography coupled to diode array detection and high resolution multiple stage mass spectrometry (UHPLC/DAD/HRMS). The metabolomic and quantitative results of this study support the hypothesis of the possible relationship between the phenolic content of wild apples and their resistance to P. expansum. Apple accessions resistant to P. expansum had higher concentrations of procyanidins, dihydrochalocone, flavonols, and hydroxycinnamic acids.Findings from this study may lead to development of the physiological markers of resistance that could be used by breeders in evaluating crosses for resistance to blue mold and may be helpful to further define apple defense mechanism(s) against P. expansum.

Phenolic composition and antioxidant capacity of Ugni molinae Turcz. leaves of different genotypes

Ugni molinae Turcz. is a native shrub of Chile, known for its edible berries and its leaves, which have been the focus of recent attention, as a good source of phenolic compounds to be used in cosmetics and food products. The aim of this study was to assess the differences in the phenolic composition and antioxidant capacity of the ethanolic extracts from the leaves of 10 genotypes of U. molinae, that were cultivated under the same soil, climate and agronomical management. Antioxidant activity was assessed by complementary methods (ORAC-Fl, FRAP and DPPH assay), phenolic composition of each extract was analyzed by LC–MS. Phenolic and flavonoid total contents were determined by Folin-Ciocalteu and AlCl3 methods. Significative differences were found by these methods, and ellagitannins, gallic acid derivatives and flavonols were identified as responsible for these differences, showing the influence of the genotype on the phenolic composition of U. molinae leaves.

Phenolic Assesment of Uncaria tomentosa L. (Cat's Claw): Leaves, Stem, Bark and Wood Extracts.

The phenolic composition of extracts from Uncaria tomentosa L. from different regions of Costa Rica was studied using advanced analytical techniques such as UPLC/TQ-ESI-MS and 13C-NMR. Samples from leaves, stems, bark and wood (n = 22) were subjected to extraction to obtain phenolic and alkaloid extracts, separately. Comparatively, higher values of total phenolic content were observed for leaves, stems and bark (225–494 gallic acid equivalents/g) than for wood extracts (40–167 gallic acid equivalents/g). A total of 32 non-flavonoid and flavonoid compounds were identified in the phenolic extracts: hydroxybenzoic acids (benzoic, salicylic, 4-hydroxybenzoic, prochatechuic, gallic, syringic and vanillic acids), hydroxycinnamic acids (p-coumaric, caffeic, ferulic and isoferulic acids), flavan-3-ols monomers [(+)-catechin and (−)-epicatechin)], procyanidin dimers (B1, B2, B3, B4, B5, B7 and two other of unknown structure) and trimers (C1, T2 and one of unknown structure), flavalignans (four unknown structures pertaining to the cinchonain family) and propelargonidin dimers (four unknown structures, reported for the first time in U. tomentosa). Additionally, alkaloid extracts obtained from the plant residue after phenolic extraction exhibited a content of tetracyclic and pentacyclic alkaloids ranging between 95 and 275 mg/100 g of dry material for bark extracts, and between 30 and 704 mg/100 g for leaves extracts. In addition, a minor alkaloid was isolated and characterized, namely 18,19-dehydrocorynoxinoic acid. Our results confirmed the feasibility of U. tomentosa as a suitable raw material for obtaining phenolic- and alkaloid-rich extracts of potential interest.

Drying at high temperature for a short time maximizes the recovery of olive leaf biophenols

In the current study, recovery of phenolic compounds from fresh, air-dried, freeze-dried and oven-dried (at 60°C and 105°C) olive leaves was investigated. The phenol content and antioxidant activity were assessed by gross quantitative methods such as total phenol content (Folin–Ciocalteu’s method), total flavonoid content, total o-diphenol content and total antioxidant capacity using ABTS+° and DPPH° scavenging assays. In addition, the phenolic composition of extracts was determined by high performance liquid chromatography (HPLC) equipped with diode array detection (DAD) with tandem mass (MS/MS) and the contribution of individual phenolic components to the antioxidant activity of extracts were evaluted by online ABTS scavenging assay. Extracts obtained from oven-dried leaves at 105°C showed the highest phenol recoveries and antioxidant activities, whereas extracts obtained from oven-dried leaves at 60°C had the lowest values. Oven drying of olive leaves at 105°C for three hours increased oleuropein recovery up to 38 fold as compared with fresh olive leaves. Our results stress the paramount importance of sample pre-treatment in the preparation and analysis of herbal medicines. Futhermore, we highlight the limitations of sole dependence on gross assessment of total phenolic composition and total antioxidant activity in studying plant samples.

The effect of different extraction techniques on the composition and antioxidant activity of cherry laurel (Prunus laurocerasus) leaf and fruit extracts

The effects of different extraction techniques, including microwave and ultrasound assisted, classical and Soxhlet extraction, on the extractive yield, phenolic composition and DPPH-scavenging activity of cherry laurel leaf and fruit extracts were compared. The total phenolic and flavonoid content was determined according to the Folin–Ciocalteu and aluminum chloride methods, respectively. The antioxidant activity of the methanolic extract was evaluated according to the DPPH assay, while the phenolic composition was determined using the HPLC. The results showed that the extracting techniques and nature of the plant material significantly affect the extractive yield and phenolic composition of the extracts. The different plant material showed significant differences in the total phenolic content (119.4±1.1 to 36.2±0.6mg of gallic acid/g of dry extract), the total flavonoid content (66.6±0.2 to 12.9±0.2mg of rutin/g of dry extract) and the antioxidant activity (108.1±7.7 to 271.2±7.6μg/ml) (p<0.05). The highest extractive yields for both plant materials (leaves and fruit) were obtained by the Soxhlet extraction, while the extracts obtained by microwave-assisted extraction contained the highest amount of phenolic and flavonoid compounds and exhibited the best antioxidant activity. High correlations between phenolic compositions and antioxidant activities of both analyzed extracts were observed. Independently of the plant material and technique applied, chlorogenic acid was the major phenolic compound in all the extracts. o-Coumaric acid, quercetin 3-glucoside, luteolin 7-glucoside, apigenin 7-glucoside, kaempferol 3-glucoside, and naringenin were detected in the leaf extracts for the first time, while the presence of vanilic acid, caffeic acid, and rutin was confirmed in the fruit extracts.

Comparison of phenolic composition and antioxidant properties of two native Chilean and one domestic strawberry genotypes

The phenolic composition of extracts from the forms chiloensis and patagonica of Fragaria chiloensis were compared with that of the commercial strawberry Fragaria × ananassa cv. Chandler by high performance liquid chromatography with diode-array detector (HPLC–DAD) and high performance liquid chromatography with electrospray ionization mass spectroscopy detector (HPLC–ESI–MS). The phenolic constituents in the three species were mainly proanthocyanidins, hydrolysable tannins, anthocyanins and flavonol glycosides. In both native strawberry species the main flavonol glycoside was quercetin 3- O-glucuronide and the minor anthocyanins identified were cyanidin-malonyl-glucoside and pelargonidin-malonyl-glucoside. The highest anthocyanin content was found in the commercial red strawberry while ellagic acid was the main phenolic in the native white strawberry. From the methanolic fruit extract of the native Chilean strawberry Fragaria chiloensis ssp. chiloensis f. chiloensis four known antioxidants were isolated by selective fractionation using the bleaching of the free radical scavenger 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the guiding assay. The antioxidant properties (measured as the bleaching of the DPPH radical) were determined for methanol extracts of the three fruits, for fractions of F. chiloensis ssp. chiloensis f. chiloensis, and for the isolated compounds cyanidin-3-glucoside, pelargonidin-3-glucoside, quercetin-3-glucuronide and ellagic acid. This study allows a clear chemical differentiation between the commercial strawberry and the Chilean white strawberry.

Antioxidant activities and phenolic composition of extracts from Greek oregano, Greek sage, and summer savory.

Oregano vulgare L. ssp. hirtum (Greek oregano), Salvia fruticosa (Greek sage), and Satureja hortensis (summer savory) were examined as potential sources of phenolic antioxidant compounds. The antioxidant capacities (antiradical activity by DPPH* test, phosphatidylcholine liposome oxidation, Rancimat test) and total phenol content were determined in the ethanol and acetone extracts of the dried material obtained from the botanically characterized plants. The ground material was also tested by the Rancimat test for its effect on the stability of sunflower oil. The data indicated that ground material and both ethanol and acetone extracts had antioxidant activity. Chromatographic (TLC, RP-HPLC) and NMR procedures were employed to cross-validate the presence of antioxidants in ethanol and acetone extracts. The major component of all ethanol extracts was rosmarinic acid as determined by RP-HPLC and NMR. Chromatography indicated the presence of other phenolic antioxidants, mainly found in the acetone extracts. The presence of the flavones luteolin and apigenin and the flavonol quercetin was confirmed in the majority of the extracts by the use of a novel (1)H NMR procedure, which is based on the strongly deshielded OH protons in the region of 12-13 ppm without previous chromatographic separation. This deshielding may be attributed to the strong intramolecular six-membered ring hydrogen bond of the OH(5)...CO(4) moiety.