Phenolics in cereals, fruits and vegetables: Occurrence, extraction and analysis

Review on nutritional composition of orange-fleshed sweet potato and its role in management of vitamin A deficiency

A wide variety of the roots and tubers plays a major role in human diet, animal feed, and industrial raw materials. Sweet potatoes (SPs) play an immense role in human diet and considered as second staple food in developed and underdeveloped countries. Moreover, SP production and management need low inputs compared to the other staple crops. The color of SP flesh varied from white, yellow, purple, and orange. Scientific studies reported the diversity in SP flesh color and connection with nutritional and sensory acceptability. Among all, orange-fleshed sweet potato (OFSP) has been attracting food technologists and nutritionists due to its high content of carotenoids and pleasant sensory characteristics with color. Researchers reported the encouraging health effects of OFSP intervention into the staple food currently practicing in countries such as Uganda, Mozambique, Kenya, and Nigeria. Scientific reviews on the OFSP nutritional composition and role in vitamin A management (VAM) are hardly available in the published literature. So, this review is conducted to address the detailed nutritional composition (proximate, mineral, carotenoids, vitamins, phenolic acids, and antioxidant properties), role in vitamin A deficiency (VAD) management, and different food products that can be made from OFSP.

Natural antioxidants of plant origin

Interest in the content of natural antioxidants in plant-based foods can be from the human health perspective, in terms of how these compounds might help promote one's health and wellness, or from the storage point-of-view, as the endogenous antioxidant constituents aid to extend a foodstuff's shelf-life. This chapter reports essential information about the mechanism of antioxidant action and methods employed for determination of their activity, classes of phenolic compounds (phenolic acids, flavonoids, lignans, stilbenes, tannins), sources of plant antioxidants (oil seeds, cereals, legumes, plants of the Lamiaceae family, tea and coffee, tree nuts, fruits, and berries), extraction strategies of phenolic compounds from plant material, and the influence of processing and storage on the content of natural antioxidants in foods and their antioxidant activity. Thermal processing, if not releasing bound phenolics from the structural matrices of the food, tends to decrease the antioxidant potential or, in the best case scenario, has no significant negative impact. Gentler sterilization processes such as high-pressure processing tend to better retain the antioxidant potential of a foodstuff than thermal treatments such as steaming, boiling, or frying. The impact of processing can be assessed by determining the antioxidant potential of foodstuffs either at the point of formulation or after different periods of storage under specified conditions.

A Critical Review of Phenolic Compounds Extracted from the Bark of Woody Vascular Plants and Their Potential Biological Activity

Polyphenols are one of the largest and most widespread groups of secondary metabolites in the plants world. These compounds are of particular interest due to their occurrence and the properties they possess. The main sources of phenolic compounds are fruits and vegetables, but lately, more and more studies refer to woody vascular plants, especially to bark, as an important source of phenolic compounds with a potential biological effect. This study aims to bring together information on the phenolic compounds present in the bark of woody vascular plants by discussing extraction methods, the chemical composition of the extracts and potential biological effects. The literature data used in this paper were collected via PubMed (2004⁻2019). Search terms were: bark, rhytidome, woody vascular plant, polyphenols, phenolic compounds, biologic activity, antioxidant, immunostimulatory, antimutagenic, antibacterial, anti-inflammatory, and antitumoral. This paper intends to highlight the fact that the polyphenolic extracts obtained from the bark of woody vascular plants represent sources of bioactive compounds with antioxidant, immunostimulatory, antimutagenic, antibacterial properties, etc. Future research directions should be directed towards identification and isolation of bioactive compounds. Consequently, biologically active compounds obtained from the bark of woody plants could be exploited on an industrial scale.

Comparison of Phenolic Contents and Biological Potential of Different Polar Extracts of Micromeria graeca, from Algeria

Methods:

The total phenolic and flavonoid contents were determined by the Folin-Ciocalteu and aluminium chloride methods, respectively. The antioxidant capacity of the extracts was evaluated using three different assays. The antifungal capacity against the two strains Candida albicans and Aspergillus niger by using the method of diffusion on disc was also carried out.

Results:

The 50% acetonic extract gave a better rate of extraction which is 14.4% and presents the highest contents in total phenolics and flavonoids which are of 46.7 ± 2.3 mg gallic acid equivalent /g dry matter and 2.4 ± 0.1 mg quercetin equivalent/g dry matter respectively. A better antioxidant activity for the various tests was observed for 50% methanolic and acetonic extracts. The extract of 50% acetone recorded the most important antifungal activity.

Conclusion:

The findings of this study showed that the extract prepared with the 50% acetone from Micromeria graeca has the highest phenolics content and revealed the best biological activities. So, this study has allowed us to find the suitable solvent for the preparation of the M. graeca extract for several uses.

Kinetics of complex formation of Fe(III) with caffeic acid: Experimental and theoretical study

Kinetic study on the complexation of caffeic acid with ferric chloride was performed in aqueous solution at pH 9.0. The complex was characterized by IR, UV-Vis spectroscopy and FE-SEM techniques. Kinetic data were obtained and used to model the reaction kinetics for the disappearance of the caffeic acid. The operational variables have been studied in the temperature range from 25 to 45 °C, initial iron and caffeic acid concentration from 0.6 mg/100 ml (ranging from 2.0 ml to 8 ml/100 ml). The complexation reaction was found to be a first-order with rate constants for k₁ (formation) 4.7 × 10^-3 s^-1. Additionally, the effect of concentration and temperature on the complexation reaction was investigated. Apparent kinetic parameters of the complex formation of Fe(III) with caffeic acid were found as; pre-exponential factor A (-1.17 min^-1), enthalpy of activation (ΔH°)# (-2188 J mol^-1), entropy of activation, (ΔS°)# (-7.34 J mol^-1 K^-1) and Gibbs free energy of activation, (ΔG°)#(-0.68 J). The apparent activation energy of the complexation reaction was evaluated to be 289.29 J mol^-1 which is consistent with the chemistry of Fe(III) with polyphenols which are supposed to mimic the interaction of Fe(III) with transferrin in biological media. Various theoretical parameters of the studied complex such as hardness, electronegativity, softness, total energy, dipole moment and point group symmetry were calculated employing Density functional theory (DFT) and found as 0.04465, 0.2130, 22.39, 0.5201 × 10^-8 eV, 15.13 Debye, and C1, respectively.

Cold plasma treatment to improve germination and enhance the bioactive phytochemical content of germinated brown rice

The changes in the bioactive phytochemicals of six cultivars of Thai germinated brown rice (GBR) were monitored in parallel to those of cold plasma-treated GBR (PGBR). After treatment with the optimal plasma conditions, the germination percentage, root length, and seedling height measurements of the most sensitive rice cultivar increased by 84%, 57%, and 69%, respectively. For all of the rice cultivars, there were no significant differences in the antioxidant activities of the GBRs and PGBRs. Conversely, higher contents of γ-oryzanols were observed in the PGBR group than in the GBR group during the 2-day germination period. Certain cultivars in the PGBR group reached their maximum values for total phenolic compounds, total vitamin E, certain simple phenolics, phytosterols, triterpenoids, and anthocyanins one day earlier than the same values for GBR. In contrast, the concentrations of 2-acetyl-1-pyrroline in both the GBR and PGBR samples were reduced significantly with increased germination time.

Effects of simulated digestion on the phenolic composition and antioxidant activity of different cultivars of lychee pericarp

Background

Lychee pericarp is rich in phenolic and has good antioxidant activity. The effects of simulated gastric (SGF) and intestinal fluid (SIF) digestion on the contents, composition, and antioxidant activities of the phenolic substances in the pericarp of different lychee cultivars (cv Jizui, Lizhiwang, Guiwei, Yuhe, Nuomici and Guihong) were investigated.

Results

Compared with distilled water (DW) treatment, the total phenolic content (TPC) and total flavonoid content (TFC) in the pericarp of different lychee cultivars decreased after SGF digestion; especially, the TFC in "Lizhiwang" decreased by 41.5%. The TPC and TFC of lychee pericarp also decreased after SIF digestion. However, the TPC in "Jizui", "Guiwei" and "Yuhe" increased. The SGF and SIF also had different effects on the FRAP and ABTS antioxidant activities of different lychee cultivars. The SGF digestion decreased the ABTS antioxidant capacity of lychee pericarp but enhanced the FRAP value of some lychee cultivars. However, the SIF digestion decreased the FRAP antioxidant activity of different lychee cultivar pericarps but enhanced the ABTS antioxidant capacity of lychee. The HPLC results showed that lychee pericarp had relatively high contents of procyanidin B2 and procyanidin A2. After SIF digestion, caffeic acid and isoquercitrin could not be detected in any of the lychee varieties. However, quercetin-3-rutinose-7-rhamnoside and isoquercitrin were increased after SGF digestion.

Conclusions

Lychee pericarp could be used as an inexpensive functional food ingredient.

Phytochemical Content of Melissa officinalis L. Herbal Preparations Appropriate for Consumption

Melissa Officinalis L. (MOL) domestic preparations appropriate for consumption were studied by monitoring content in Na, K, Ca, Li, phenolic bioactives (total phenols, hydroxycinnamic acid derivatives and flavonols), and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl radical inhibition (DPPH) and ferric reducing ability (FRAP)). The effects of practice applied, material to solvent ratio, time of preparation, and solvent were studied. MOL decoctions and infusions, commonly prepared at home, were better or of equal nutritional value to preparations upon ultrasounds or maceration concerning the studied parameters. Aqueous MOL preparations were richer in total phenols (704–1949 mg per 250 mL) and the examined macroelements (1.1–2.9, 30.5–288.4 and 50.1–176.1 mg Na, K and Ca per 250 mL, respectively) and showed better antioxidant activity compared to ethanol counterparts. The 25% w/v hydroethanolic MOL preparations, suitable for consumption, presented a significant content in phenolic antioxidants and in the examined minerals, too. MOL infusions were significantly richer in total phenols with respective chamomile and olive leaf ones, comparatively examined. Overall acceptance scores of aqueous MOL preparations indicated that bitterness has to be masked for efficient reception by the consumers.

Effect of Solvents on Phytochemicals Content and Antioxidant Activity of Ganoderma lucidum

Introduction:

The aim of this study was to assess the induction of solvents on the total phenol and flavonoid content and also the antioxidant activity of Ganoderma lucidum extracts.

Materials & Methods:

In this study, two concentrations (100% and 75%) of diethyl ether, ethanol, butanol, chloroform, and acetone were used as extractants of Ganoderma lucidum. Total phenol and flavonoid contents were measured by spectrophotometric methods and 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Free radical scavenging assay was used for the investigation of antioxidant activity.

Results & Discussion:

Extractants significantly affected the % yield of extract, the quantity of phenol and flavonoids and antioxidant activity of Ganoderma lucidum mushroom. The highest extraction yield, around 38%, was achieved by 75% acetone, followed by 100% acetone (about 36%) and 75% chloroform (approximate 21%). Hydro-acetone extract exhibited the most significant antioxidative properties (EC50 value; 645.55 µg/mL) comprised of a higher total of phenol content. In conclusion, the total phenol content encouraged the antioxidative potential of Ganoderma lucidum mushroom.

Conclusion:

These findings indicate that the selective extraction of Ganoderma lucidum shows significant biological activities.

Impact of plant extracts upon human health: A review

With the increase in evidences directly linking diet and health, several foodstuffs, such as phenolic rich fruits and vegetables, have emerged as possessing potential health benefits. Plants, given their fiber and phenolic content (and their intrinsic biological potential), have long been considered as contributing to health promotion. Therefore, the present work aimed to review the existing evidences regarding the various potential benefits of plant extracts' and plant extract-based products' consumption, with emphasis on in vivo works and epidemiological studies whenever available. Overall, the information available supports that, while there are indications of the potential benefits of plant extracts' consumption, further human-based studies are still needed to establish a true cause-effect.

Phenolic Compounds Determined by LC-MS/MS and In Vitro Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages

The aim of this study was to investigate the free individual phenolics and the in vitro antioxidant capacity of blackberry, acerola, yellow guava, guabiju, jambolan and jabuticaba fruits in two edible stages. Of the thirty-three phenolics investigated by liquid chromatography - tandem mass spectrometry (LC-MS/MS), twenty-five were quantified and the major ones were catechin, isoquercitrin, epicatechin and gallic acid. The highest values for the total phenolic content (in dry matter) were observed for acerola (83.6 to 97.7 mg gallic acid equivalents g^-1 DM) and blackberry (18.9 to 28.3 mg gallic acid equivalents g^-1 DM); however, acerola, jabuticaba, and blackberry showed the highest antioxidant capacities (134.6 to 1120.4 mg Trolox equivalents g^-1 for 2,2-diphenyl-1-picrylhydrazyl and 43.6 to 501.8 μmol Trolox equivalents g^-1 for ferric reducing antioxidant power). For most fruits, the antioxidant capacity decreased during the ripening, possibly due to a decrease in the concentration of most of the phenolics.

Functional Redundancy in the Hydroxycinnamate Catabolism Pathways of the Salt Marsh Bacterium Sagittula stellata E-37

The hydroxycinnamates (HCAs) ferulate and p-coumarate are among the most abundant constituents of lignin, and their degradation by bacteria is an essential step in the remineralization of vascular plant material. Here, we investigate the catabolism of these two HCAs by the marine bacterium Sagittula stellata E-37, a member of the roseobacter lineage with lignolytic potential. Bacterial degradation of HCAs is often initiated by the activity of a hydroxycinnamoyl-coenzyme A (hydroxycinnamoyl-CoA) synthase. Genome analysis of S. stellata revealed the presence of two feruloyl-CoA (fcs) synthase homologs, an unusual occurrence among characterized HCA degraders. In order to elucidate the role of these homologs in HCA catabolism, fcs-1 and fcs-2 were disrupted using insertional mutagenesis, yielding both single and double fcs mutants. Growth on p-coumarate was abolished in the fcs double mutant, whereas maximum cell yield on ferulate was only 2% of that of the wild type. Interestingly, the single mutants demonstrated opposing phenotypes, where the fcs-1 mutant showed impaired growth (extended lag and ∼60% of wild-type rate) on p-coumarate, and the fcs-2 mutant showed impaired growth (extended lag and ∼20% of wild-type rate) on ferulate, pointing to distinct but overlapping roles of the encoded fcs homologs, with fcs-1 primarily dedicated to p-coumarate utilization and fcs-2 playing a dominant role in ferulate utilization. Finally, a tripartite ATP-independent periplasmic (TRAP) family transporter was found to be required for growth on both HCAs. These findings provide evidence for functional redundancy in the degradation of HCAs in S. stellata E-37 and offer important insight into the genetic complexity of aromatic compound degradation in bacteria.IMPORTANCE Hydroxycinnamates (HCAs) are essential components of lignin and are involved in various plant functions, including defense. In nature, microbial degradation of HCAs is influential to global carbon cycling. HCA degradation pathways are also of industrial relevance, as microbial transformation of the HCA, ferulate, can generate vanillin, a valuable flavoring compound. Yet, surprisingly little is known of the genetics underlying bacterial HCA degradation. Here, we make comparisons to previously characterized bacterial HCA degraders and use a genetic approach to characterize genes involved in catabolism and uptake of HCAs in the environmentally relevant marine bacterium Sagittula stellata We provide evidence of overlapping substrate specificity between HCA degradation pathways and uptake proteins. We conclude that S. stellata is uniquely poised to utilize HCAs found in the complex mixtures of plant-derived compounds in nature. This strategy may be common among marine bacteria residing in lignin-rich coastal waters and has potential relevance to biotechnology sectors.

Polymeric stationary phases based on poly(butylene terephthalate) and poly(4-vinylpirydine) in the analysis of polyphenols using supercritical fluid chromatography. Application to bee pollen

Two new polymer-based stationary phases; DCpak PBT (poly(butylene terephthalate)) and DCpak P4VP (poly(4-vinylpirydine)) were evaluated for the analysis of polyphenols using supercritical fluid chromatography (SFC). The compounds studied included phenolic acids and flavonoids. The different variables that influence the chromatographic separation, such as type and percentage of organic modifier, additive, pressure and temperature were examined. Using the DCpak P4VP column the retention was exceptionally high, obtaining better results with the DCpak PBT column. The separation of nine polyphenols was achieved using a gradient of modifier (methanol with 0.1% trifluoroacetic acid) from 5 to 50%, a pressure of 150 bar, a temperature of 35 °C and a flow-rate of 2 mL/min. The use of additives was necessary in order to obtain good peak shapes and efficiencies, achieving the best results with trifluoroacetic acid. LODs and LOQs values were lower than 5 μg/mL in all the cases; meanwhile, the %RSD values for method repeatability and inter-day reproducibility were lower than 3% and 10% respectively. Finally, the proposed method was successfully applied to the analysis of polyphenols in commercial bee pollen; four compounds, namely cinnamic acid, p-coumaric acid, catechin and quercetin were identified and quantified.

Antibacterial and antioxidant activities for natural and synthetic dual-active compounds

Antimicrobial resistance is widely recognized as a grave threat to global health in the 21st century, since the past decades have seen a dramatic increase in human-pathogenic bacteria that are resistant to one or multiple antibiotics. New antimicrobial agents are urgently required, particularly in the treatment of chronic infections such as cystic fibrosis, often associated with persistent colonization by drug-resistant pathogens and epithelial damage by pulmonary oxidative stress. In such events, it would be favourable to find agents that could have antioxidant and antibacterial activities combined in one molecule. The discovery of compounds that can show a dual-target activity considerably increased in the last years, reflecting the growing confidence that this new approach could lead to better therapeutic solutions for complex multigenic diseases. The aim of this review is to report those natural and synthetic compounds displaying significant antioxidant and antibacterial activities. In recent years there has been a growing attention on plant-derived antimicrobials as an alternative to antibiotics, for their efficacy and low tendency in developing bacterial resistance. Moreover, it was found that some natural products could enhance the activity of common antibiotics displaying a synergistic effect. We then report some selected synthetic compounds with an in-built capacity to act on two targets or with the combination in a single structure of two pharmacophores with antioxidant and antibacterial activities. Recent literature instances were screened and the most promising examples of dual-active antibacterial-antioxidant molecules were highlighted.

Effect of Processing on Bioactive Compounds, Physicochemical and Rheological Characteristics of Juçara, Banana and Strawberry Smoothie

This study aimed to evaluate the effect of processing steps on bioactive compounds and physicochemical and rheological characteristics of a juçara, banana and strawberry smoothie. The product was obtained by mixing the pulps of these fruits in previously defined proportions. The mixture was standardized in a pilot disintegrator, homogenized at 60 MPa in continuous mode and pasteurized at 90 °C for 35 s. The homogenization step increased the concentration of cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside, major anthocyanins in the smoothie. However, these anthocyanins, as well as perlagonidin-3-O-glucoside, have been reduced (p<0.05) after the pasteurization step. The pasteurization also affected the instrumental color of the smoothie, expressed by Hue angle (p<0.05). Regarding to the rheological behavior, the smoothie, in all processing steps, presented a non-Newtonian fluid behavior with pseudoplastic characteristics (n<1). After homogenization, the smoothie became more fluid and homogeneous. Thus, despite the negative impact of pasteurization on the smoothie's color, the pasteurized product preserves the bioactive compounds such as flavonoids and phenolic acids that are of great importance to human health. Furthermore, the development of this product contributes to add value to the juçara agro-chain and Atlantic Forest preservation.

Antioxidant activity of carob seeds and chemical composition of their bean gum by- products

Background The carob (Ceratonia siliqua L.) is very old edible fruit, flavorful and often used in foods and beverages. In this present study the composition of phenolic compounds, the antioxidant activity and the production locust bean gum (LBG) of seeds grown in Algeria was explored. Methods The phenolic contents (total phenolics, total tannins, total flavonoids, condensed tannins and flavonols) and the antioxidant activity of the aqueous methanolic, ethanolic and acetonic extracts (70, 80 and 80v/v, respectively) of the seeds were determined using colorimetric methods. Furthermore, the carob bean gum from seeds was extracted and its chemical composition was evaluated. Results Aqueous acetonicextract of carob seeds give the highest contents of total phenolics, total flavonoids, flavonols, total tannins and condensed tannins which were 12.24±0.02, 1.33±0.01, 2.97±0.01, 4.29±0.2 and 0.53±0.01 mg/g of dry weight, respectively. The same extract showed also the best antioxidant activity in all assays compared to other extracts.

Phytochemical composition and in vitro antioxidant activities of Citrus sinensis peel extracts

BACKGROUND

Citrus sinensis peels are usually discarded as wastes; however, they are rich sources of Vitamin C, fibre, and many nutrients, including phenolics and flavonoids which are also good antioxidant agents. This study aimed to examine phytochemical composition and antioxidant capabilities of C. sinensis peel extracted conventionally with different methanol/water, ethanol/water, and acetone/water solvents.

METHODS

C. sinensis peels were subjected to extraction with 100%, 70% and 50% of methanol, ethanol, and acetone, respectively, as well as hot water extraction. Antioxidant activities of the peel extracts were examined via the 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant power (FRAP) assay, and oxygen radical absorbance capacity (ORAC) assay. Total phenolic content and total flavonoid content of the extracts were measured via the Folin-Ciocalteau method and the aluminium chloride colorimetric method, respectively. Phenolic acid and organic acid composition of the peel extracts were further determined via high performance liquid chromatography (HPLC) while flavonoid content was identified via ultra performance liquid chromatography (UPLC).

RESULTS

DPPH radical scavenging activity of C. sinensis peel extracts varied from 8.35 to 18.20 mg TE/g, FRAP ranged from 95.00 to 296.61 mmol Fe(II)/g, while ORAC value ranged from 0.31 to 0.92 mol TE/g. Significant level of association between the assays was observed especially between TPC and FRAP (R-square = 0.95, P < 0.0001). TPC of various C. sinensis peel extracts ranged from 12.08 to 38.24 mg GAE/g, with 70% acetone/water extract (AEC) showing the highest TPC. TFC ranged from 1.90 to 5.51 mg CE/g. Extraction yield ranged from 0.33 to 0.54 g/g DW and tended to increase with increasing water concentration in the solvent. In the phytochemical investigation, five phenolic acids were identified using HPLC, including gallic acid, protocatechuic acid, 4-hydroxybenzoic acid, caffeic acid and ferulic acid. A total of five organic acids including lactic acid, citric acid, L-mallic acid, kojic acid and ascorbic acid were quantified via HPLC. In addition, concentrations of six flavonoids including catechin, epigallocatechin, vitexin, rutin, luteolin and apigenin were determined via UPLC.

DISCUSSION AND CONCLUSION

Phytochemicals including phenolics and flavonoids in C. sinensis peel extracts exhibited good antioxidant properties. Among the extracts, 70% AEC with highest TPC and high TFC content showed greatest antioxidant activity in all three assays. Different phenolic acids, organic acids and flavonoids were also identified from the extracts. This study indicated that C. sinensis peels contained potential antioxidant compounds which could be exploited as value added products in the food industry.

Metabolite profiling of "green" extracts of Corylus avellana leaves by 1H NMR spectroscopy and multivariate statistical analysis

Corylus avellana L. (Betulaceae) leaves, consumed as infusion, are used in traditional medicine, for the treatment of hemorrhoids, varicose veins, phlebitis, and edema due to their astringent, vasoprotective, and antiedema properties. In previous works we reported from the leaves of Corylus avellana cv. "Tonda di Giffoni" diarylheptanoid derivatives, a class of plant secondary metabolites with a wide variety of bioactivities. With the aim to give an interesting and economically feasible opportunity to C. avellana leaves as source of functional ingredients for pharmaceutical and cosmetic formulations, "green" extracts were prepared by employing "eco-friendly" extraction protocols as maceration, infusion and SLDE-Naviglio extraction. Metabolite profiles of the extracts were obtained by ¹H NMR experiments and data were processed by multivariate statistical analysis to highlight differences in the extracts and to evidence the extracts with the highest concentrations of bioactive metabolites. Based on the NMR data, a total of 31 compounds were identified. The metabolite variation among the extracts was evaluated using Principle Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA). Furthermore, the total phenolic content of the extracts was measured by Folin-Ciocalteu colorimetric assay and the antioxidant activity of extracts was assayed by the spectrophotometric tests DPPH^• and ABTS and by an in vitro test based on the evaluation of cellular reactive oxygen species production stimulated by pyocyanin.

Implication of the Significance of Dietary Compatibility: Based on the Antioxidant and Anti-Inflammatory Interactions with Different Ratios of Hydrophilic and Lipophilic Antioxidants among Four Daily Agricultural Crops

The hydrophilic extracts of eggplant peel (HEEP) and purple sweet potato (HEPP) and lipophilic extracts of tomato (LET) and carrot (LEC) were mixed in different ratios to assess the significance of the compatibility of aliments, based on their antioxidant and anti-inflammatory interactions in H9c2 cells. The results indicated that groups of some combinational extracts (HEPP-HEEP F1/10, LEC-HEEP F3/10, LEC-HEPP F3/10) showed stronger synergistic antioxidant and anti-inflammatory effects than individual groups. For example, the glutathione peroxidase (GPx) activity of the LEC-HEEP (F3/10) group (86.71 ± 1.88) was higher than that in the HEEP (79.97 ± 1.68) and LEC (77.31 ± 1.85) groups. The level of reactive oxygen species (ROS) was 30.37 ± 0.25 in the LEC-HEEP (F3/10) group while the levels were 34.34 ± 0.36 and 46.23 ± 0.51 in the HEEP and LEC groups, respectively. And the level of malondialdehyde (MDA) was 1.82 ± 0.24 in the LEC-HEEP (F3/10) group while the levels were 2.48 ± 0.13 and 3.01 ± 0.24 in the HEEP and LEC groups, respectively. The expressions of inflammatory mediators (IL-1β, IL-6, IL-8) and cell adhesion molecules (VCAM-1, ICAM-1) showed similar tendencies. However, some groups (LET-LEC F5/10, LET-LEC F9/10, LET-HEPP F7/10) showed antagonistic effects based on these indicators. The principal component analysis showed that samples could be defined by two principal components: PC1, the main phenolic acids and flavonoids; PC2, carotenoids. Moreover, phenolics and anthoyanins were in the majority in synergistic groups, and carotenoids were in the majority in antagonistic groups. These results indicated that there exist synergistic or antagonistic interactions of aliments on antioxidation and anti-inflammation, which implied the significance of food compatibility.

Simultaneous Preparation of Salidroside and p-Tyrosol from Rhodiola crenulata by DIAION HP-20 Macroporous Resin Chromatography Combined with Silica Gel Chromatography

The Rhodiola species have a long history of utilization in traditional medicine and have been considered as a source of adaptation to environmental challenges; salidroside and p-tyrosol are the major responsible compounds. Here we propose a novel UPLC-guided two-step method consisting of a DIAION HP-20 adsorption and silica gel column chromatographies, which can simultaneously prepare high purities of salidroside and p-tyrosol with noticeable yields from the rhizome of Rhodiola crenulata. Results demonstrated that DIAION HP-20 could successfully remove all impurities except crenulatin during a gradient elution with 5–20% ethanol, which could achieve an optimal purification of salidroside and p-tyrosol with increasing rates of 29.19% and 33.44%, respectively. Furthermore, chloroform was selected as an ideal solvent for separating p-tyrosol with salidroside, and thus crenulatin was subsequently applied in the silica gel chromatography, and the separation of salidroside with crenulatin could be achieved using silica gel chromatography with a mixture of chloroform and methanol at a volume ratio of 4:1. High purity rates of 94.17% and 97.29% and overall yields of 39.09% and 43.73% for salidroside and p-tyrosol were simultaneously achieved. Our method provides a new way to simultaneously obtain salidroside and p-tyrosol from R. Crenulata, as well as other related plant species.

Enhanced yield of oleuropein from olive leaves using ultrasound-assisted extraction

The aim of this study was to optimize the extraction of oleuropein from olive leaves through a systematic study of the effects of different parameters of ultrasound-assisted extraction (USAE) on the oleuropein yield, in comparison with conventional maceration extraction. A range of operational parameters were investigated for both conventional maceration extraction and USAE: solvent type, olive leaf mass-to-solvent volume ratio, and extraction time and temperature. Oleuropein yield was determined using high-performance liquid chromatography, with total phenolics content also determined. The optimized conditions (water-ethanol, 30:70 [v/v]; leaf-to-solvent ratio, 1:5 [w/v]; 2 hr; 25°C) provided ~30% greater oleuropein extraction yield compared to conventional maceration extraction. The total phenolics content obtained using the optimized USAE conditions was greater than reported in other studies. USAE is shown to be an efficient alternative to conventional maceration extraction techniques, as not only can it offer increased oleuropein extraction yield, but it also shows a number of particular advantages, such as the possibility of lower volumes of solvent and lower extraction times, with the extraction carried out at lower temperatures.

A simple ultrasensitive electrochemical sensor for simultaneous determination of gallic acid and uric acid in human urine and fruit juices based on zirconia-choline chloride-gold nanoparticles-modified carbon paste electrode

The determination of gallic acid (GA) and uric acid (UA) is essential due to their biological properties. Numerous methods have been reported for the analysis of GA and UA in various real samples. However, the development of a simple, rapid and practical sensor still remains a great challenge. Here, a carbon paste electrode (CPE) was modified by nanocomposite containing zirconia nanoparticles (ZrO₂NPs), Choline chloride (ChCl) and gold nanoparticles (AuNPs) to construct ZrO₂-ChCl-AuNPs/CPE as electrochemical sensor for the simultaneous electro-oxidation of GA and UA. Characterization was performed by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The modified electrode was investigated by different methods including electrochemical impedance spectroscopy and cyclic voltammetry. Kinetic parameters such as charge transfer coefficient, standard heterogeneous electron transfer rate constant and other parameters were calculated via voltammetry techniques. Differential pulse voltammetry was used for simultaneous determination of GA and UA applying the ZrO₂-ChCl-AuNPs/CPE electrode. At the optimum conditions, this sensor showed a linear response in the ranges 0.22- 55 and 0.12-55 µM for GA and UA, respectively. In addition, low detection limits of 25 and 15 nM were obtained for GA and UA, respectively. Furthermore, ZrO₂-ChCl-AuNPs/CPE was successfully applied for the independent determination of GA in green tea and fruit juice as well as the simultaneous determination of GA and UA in human urine samples.

HPLC-ED Analysis of Phenolic Compounds in Three Bosnian Crataegus Species

The aim of this work was the qualitative and quantitative determination of selected phenolic compounds in three Crataegus species grown in Bosnia. Crataegus plants are consumed for medicinal purposes and as foodstuff in the form of canned fruit, jam, jelly, tea, and wine. Two samples of plant material, dry leaves with flowers, and berries of three Crataegus species—Crataegus rhipidophylla Gand., Crataegus x subsphaericea Gand., and Crataegus x macrocarpa Hegetschw.—were analyzed. Twelve ethanolic extracts were isolated from the selected plant material using Soxhlet and ultrasound extraction, respectively. Soxhlet extraction proved to be more effective than ultrasound extraction. A simple and sensitive method, high-performance liquid chromatography with electrochemical detection, HPLC-ED, was used for the simultaneous determination of phenolic acids and flavonoids in Crataegus species. The content of gallic acid in the extracts ranged from 0.001 to 0.082 mg/g dry weight (DW), chlorogenic acid from 0.19 to 8.70 mg/g DW, and rutin from 0.03 to 13.49 mg/g DW. Two flavonoids, vitexin and hyperoside, commonly found in chemotaxonomic investigations of Crataegus species, were not detected in the examined extracts. In general, leaves with flowers samples are richer in gallic acid and rutin, whereas the berries samples are richer in chlorogenic acid. Distinct similarities were found in the relative distribution of gallic acid among the three species. Extracts of C. x macrocarpa had the highest content of all detected compounds, while significant differences were found in rutin content, depending on the plant organ. To the best of our knowledge, this is the first study reporting content of phenolic compounds in Crataegus rhipidophylla Gand., Crataegus x subsphaericea, and Crataegusxmacrocarpa from Bosnia.

HPLC-DAD identification of polyphenols from ethyl acetate extract of Amaranthus spinosus leaves and determination of their antioxidant and antinociceptive effects

Amaranthus spinosus has been consumed traditionally to prevent various diseases including abdominal pain. In this study, the phytochemical composition, antioxidant and analgesic activities of an ethyl acetate extract of A. spinosus leaves (ASEA) were evaluated. The ASEA had the highest concentrations of total phenols (462.2 mg GAE/g DW), condensed tannin (5.01 mg CE/g DW) and total flavonoid contents (30.07 mg CE/g DW) compared to the chloroform, n-hexane, n-butanol and water extracts. Similarly, ASEA showed the most effective total antioxidant activity (45.45 µg/mL), DPPH scavenging activity (27.32 µg/mL) and hydrogen peroxide scavenging activity (30.60 µg/mL). ASEA with the doses of 200-600 mg/kg (p.o.) clearly demonstrated antinociceptive effects by reducing acetic acid-induced abdominal contortions with a maximal inhibition of 79.57% at 600 mg/kg and increasing latencies of the hot-plate paw-licking response. The tested doses also significantly (p < 0.001) decreased the reaction time in the formalin test at the neurogenic and inflammatory phases. ASEA contained ten polyphenols with caffeic acid being the predominant polyphenol. Overall, this study gave evidence that A. spinosus is a new antioxidant and analgesic agent, and justified its traditional use for the treatment of pain.

Evaluation of Volatile Profile, Fatty Acids Composition and in vitro Bioactivity of Tagetes minuta Growing Wild in Northern Iran

Purpose: The aim of the present study was to investigate the chemical properties of wild Tagetes minuta L. (family Astreacea) collected from Northern Iran during the flowering period concerning the chemical combination of the essential oil along with its antioxidant properties and composition of fatty acids.

Methods: The essential oil of the plant was extracted by a Clevenger approach and analyzed using gas chromatography-mass spectroscopy (Capillary HP-5ms GC/MS Column). Fatty acid contents of this species as a result of hexane extraction were analyzed by means of gas chromatography (GC-FID) while their phenolic contents were analyzed by high performance liquid chromatography (HPLC-UV). In this research also the total polyphenolic (TPC) and total flavonoid (TFC) content was determined spectrophotometrically while the antioxidant activity was evaluated using the DPPH (2,2'-diphenyl-1-picrylhydrazyl) bleaching method.

Results: GC/MS analysis of the essential oil identified monoterpenoid fractions (52.13%) as the main components and among them dihydrotagetone (23.44%) and spathulenol (10.56%) were the predominant compounds. The evaluation of fatty acid content revealed that saturated acids were prevailing compounds and the major components are: palmitic (30.74±0.4%) and capric (24.15±0.5%) acids. Chromatographic separation of its phenolic contents indicated that this herb contain sinapic acid derivatives rather than hydroxybenzoic acid derivatives. Also the essential oil showed an effective antioxidant capacity (TPC=153.27±0.9 mg/g, TFC=63.79±0.1 mg/g, IC₅₀ = 29.31±0.8 µg/ml).

Conclusion: The results proved that the plant could be used for nutritional and pharmaceutical purposes.

In vitro Antioxidant Potentials of Cyperus rotundus L. Rhizome Extracts and Their Phytochemical Analysis

Background:

Cyperus rotundus L. (family Cyperaceae), native to India, is a multivalent medicinal plant widely used in conventional medicine. The research reports on bioactive components from C. rotundus L. are scanty.

Objective:

The objective of the study was to optimize the best solvent system and bioprospect the possible phytochemicals in C. rotundus L. rhizome (CRR).

Materials and Methods:

The phytochemicals were extracted from the rhizomes of C. rotundus L. by successive Soxhlet technique with solvents of increasing polarity. The resultant extracts were analyzed for their total flavonoid content (TFC), total phenolic content (TPC), total proanthocyanidin content (TPAC), in vitro antioxidant potential, and inhibition of lipid peroxidation. The 70% acetone extract of CRR was analyzed using gas chromatography–mass spectrometry (GC-MS) for probable phytochemicals.

Results and Discussion:

The TPC, TFC, and TPAC estimates ranged from 0.036 ± 0.002 to 118.924 ± 5.946 μg/mg extract, 7.196 ± 0.359 to 200.654 ± 10.032 μg/mg extract, and 13.115 ± 0.656 to 45.901 ± 2.295 μg/mg extract, respectively. The quantities of TPC, TFC, and TPAC were found to be the highest in 70% acetone extract. The 70% acetone and 70% methanol extracts revealed best radical scavenging effect. GC-MS analysis of CRR extract revealed the presence of a novel compound 1 (2)-acetyl-3 (5)-styryl-5 (3)-methylthiopyrazole.

Conclusion:

The study indicated that 70% acetone and 70% methanol extracts of CRRs can be a potential source of antioxidants.

SUMMARY

The studies suggest 70% methanol and acetone as the suitable solvents for the extraction of phytochemicals

Novel compound 1(2)-Acetyl-3(5)-styryl-5(3)-methylthiopyrazole was detected in 70% acetone extract.

Abbreviations used: ACRE: Acetone C. rotundus L. rhizome extract; AlCl₃: Aluminum chloride; AQRE: Aqueous C. rotundus L. rhizome extract; CE: Catechin Equivalent; CHRE: Chloroform C. rotundus L. rhizome extract; CRR: C. rotundus L. rhizome; DPPH: 2,2 diphenyl-1-picrylhydrazyl; ETRE: Ethanolic C. rotundus L. rhizome extract; EARE: Ethyl acetate C. rotundus L. rhizome extract; FRP: Ferric reducing power; GAE: Gallic acid equivalent; GC-MS: Gas chromatography-mass spectrometry; HERE: Hexane C. rotundus L. rhizome extract; MERE: Methanolic C. rotundus L. rhizome extract; PERE: Petroleum ether C. rotundus L. rhizome extract; QE: Quercetin equivalent; RNS: Reactive nitrogen species; ROS: Reactive oxygen species; TFC: Total flavonoid content; TPC: Total phenolic content; TPAC: Total proanthocyanidin content.

Antioxidant activity and Hypolipidemic effect of Ficus carica leaf and twig extracts in Triton WR-1339-induced hyperlipidemic mice

BACKGROUND/AIM: The hypolipidemic potential of both leaf and twig extracts of Ficus carica on experimental hyperlipidaemia induced by Triton WR-1339, in Swiss albino mice was investigated. In addition, the phenolic, flavonoid and anthocyanin contents of these extracts and their antioxidant activities were determined. These properties may have a synergistic effect on hyperlipidaemia. MATERIALS AND METHODS: Leaf and twig samples of F. carica were harvested and collected. The study of antioxidant activity of phenolic compounds was determined by the radical DPPH*, ABTS*+ and FRAP assays. The experimental design was carried out using acute oral toxicity study and Triton model hyperlipidaemia on Swiss albino adult male mice. The animals were observed continuously during the 14 days of the study for any physical signs of toxicity. On the 15th day, the animals were sacrificed by decapitation under anesthesia and the organs were observed for macroscopic pathological lesions. Hyperlipidaemia was induced in the mice by a single intravenous (iv) injection of Triton WR 1339 (300 mg/kg body weight), and the antihyperlipidemic effect of each extract, studied at 150 and 300 mg, was tested by gavage. After 24 hours of administration, serum from blood samples was used to estimate the various parameters of the lipid profile namely TC, TG, LDL and HDL. RESULTS: The results of the phenolic and flavonoid compounds of Ficus carica leaves and twigs varied from 12.84 to 19.78 mg gallic acid equivalents (GAE) and 5.02 to 9.72 mg EQ/g dry matter, respectively. The scavenging activity (IC50) against the radical DPPH* and ABTS*+ varied from 346.2 to 461.38 μg/mL and 288.3 to 369.01 μg/mL for twigs and leaves respectively, and from 50.82 to 54.2 μg/mL for FRAP assay. The acute toxicity study showed no mortality and clinical signs of toxicity in the tested doses. The LD50 value of extracts of twigs and leaves of Ficus carica is greater than 5000 mg/kg. The results revealed that the administration of Ficus carica (FC) leaf and twig extracts resulted in a significant (p < 0.05) decline in levels of serum triglycerides, total cholesterol, LDL-c, and VLDL-c, while the serum high-density lipoprotein cholesterol was significantly increased. The decrease rate of the lipid parameters differs significantly (p < 0.05) from the leaf and twig extracts and depends also on the administered dose. CONCLUSION: Ficus carica leaf and twig extracts may contain compounds able to lower plasma lipid concentrations, could contribute significantly to the total antioxidant properties and be beneficial in the treatment of hyperlipidaemia.