Relative Antioxidant Activity Research Articles

Didymocarpus Pedicellate: Bioactive Constituent, Their Molecular Target in Diabetes Mellitus

Didymocarpus pedicellata (Family: Gesneriaceae), is an herbal drug traditionally used in renal disorders mainly as antiurolithiatic and do not have much data on this plant, is selected for study and hereby reviewed. This review is based on compilation of data from the various researchers on their research work and other data including anti-diabetic activity of Didymocarpus pedicellata and antioxidant activity in relation with the type 2 diabetes mellitus and its cardiovascular complications. By using various scientific studies, the evidence has been demonstrated as to the antidiabetic effect of the various extract of Didymocarpus pedicellata as well as its chemical constituents including various flavonoid like chalcones which are major bioactive constituents chiefly present in Didymocarpus pedicellata. The chalcones present in these plants have various therapeutic targets for the management of type 2 diabetes like PPARg, DPP-4, a-glucosidase, PTP1B, aldose reductase, and stimulate insulin secretion and tissue sensitivity. The Didymocarpus pedicellata has also been reported to exhibit antispasmolytic, antimalarial activity and nephroprotective activity. On the basis of given evidence, it may be concluded that Didymocarpus pedicellata could be the potential target for the treatment of type 2 diabetes mellitus and can reduce the cardiovascular complication associated with diabetes mellitus.

Callus formation, phenolics content and related antioxidant activities in tissue culture of a medicinal plant colocynth (Citrullus colocynthis)

Callus cultures from stems, leaves and roots of colocynth were initiated on MS media supplemented with various combinations of 2,4 dichlorophenoxyacetic acid (2,4-D) with kinetin (KIN) and benzyladenine (BA) with α-naphthaleneacetic acid (NAA). The highest percentage of callus formation frequency (98.9%) was obtained from stem explants grown on MS media supplemented with (1.0 mg/L) 2,4-D + (1.0 mg/L) KIN. The total phenolics and flavonoid content of the colocynth callus cultures were measured. The results showed that the MS medium supplemented with 6.0 mg/L 2,4-D + 2.0 mg/L KIN (MD3) gave the highest content of total phenolics (19.2 mg/100g d.w.) in leaf-derived calli. The highest content of flavonoids (47.3 mg/100g d.w.) was obtained in stem derived calli grown on the same medium (MD3). Antioxidant activities of extracts were determined using different assays, including DPPH radical scavenging activity, hydrogen peroxide (H2O2) scavenging activity and ferric reducing power. Leaf-derived calli cultured on MS medium + 2.0 mg/L 2,4-D + 1.0 mg/L KIN (MD1) showed the highest DPPH radical scavenging activity (85.3%). The highest percentage of H2O2 scavenging activity (61.4%) was detected in leaf explant-derived calli growing on MD1. The leaf-derived calli growing on (MD3) gave the highest ferric reducing power (22.3 μg/g d.w.), compared to the activities of stems, leaves and roots of in vitro grown seedlings (3.28, 12.9 and 2.85 μg/g d.w.), which were used as controls. On the basis of the current findings, we conclude that MS media supplemented with different combinations of 2,4-D and KIN yields higher phenolics, flavonoids contents and antioxidant activities than MS media supplemented with BA and NAA.

The Correlation of Free and Bound Phenolic Acid with Antioxidant Activity Accelerated by Germination Period and Temperature

Investigation of the free and bound phenolic acid profile in malted hulled rice and the correlation to antioxidant activity were elucidated in this study. Three of free and bound hydroxycinnamic acid (FHCAs and BHCA); p-coumaric acid (CA), ferulic acid (FA), sinapic acid (SA), and one of hydroxybenzoic acid (HBA); vanillic acid (VA) in three rice (Oryza sativa L.) cultivars (with white, red-brown, and dark-purple kernel) were germinated under warm conditions of temperature (30 °C, 35 °C and 40 °C) for 5 days and analyzed for their potential antioxidant activity. The relationship of rice cultivar, malting condition, and antioxidant activity was established by PCA bi-plot analysis. The dark-purple rice malt expressed the highest phenolic acid content and antioxidant activity. The amount of FHCA and FHBA increased with germination time, which was related to the feruloyl esterase activity assayed. Among BHCAs, BCA was the most abundant compound and correlated positively to the antioxidant activity of the bound phenolic extract of the three rice cultivars. The FVA in the dark-purple rice malt was 3 to 4 times higher than that found in white and red-brown grain and led to a strong antioxidant activity of the free form extract. This research suggests that a germination temperature of 30 °C to 35 °C improved the BCA and FVA content in the malted hulled rice cultivars and conveyed a functional property for the finished product.

Chemical analysis, antibacterial, and antioxidant activities of flavonoid‐rich extracts from four Moroccan propolis

Propolis, a resinous substance collected by honeybees from plants, is well-known worldwide for its diversified biological activities. This study was aimed to determine the chemical composition of four ethanol extracts of propolis collected from Morocco and to investigate their antibacterial and antioxidant activities. The chemical composition was determined by Ultra-High Performance Liquid Chromatography-tandem mass spectrometry. The antibacterial activity was evaluated using the well diffusion and microdilution methods. The antioxidant activity was investigated in vitro using three complementary techniques, namely reduction power, β-carotene bleaching, and DPPH scavenging assays. The identified molecules belong mainly to the flavonoid family, and interestingly, several of them were flavonoid glycosides. The four extracts showed strong antibacterial activity. The inhibitory zones varied from 10.00 ± 00 to 22.5 ± 2.12 mm, and minimal inhibitory concentration values ranged from 0.15 to >5 mg/ml, while minimal bactericidal concentration values ranged from 1.25 to >5 mg/ml. The antioxidant activity was relatively strong compared to positive controls, with IC50 varied from 67.61 to 140.04 µg/ml against DPPH free radical, and a relative antioxidant activity varied from 68.40 ± 3.90 to 100.92 ± 4.24, determined by β-carotene bleaching test. The antioxidant property was related to the chemical constituents. These results indicate that Moroccan propolis can be a valuable source of bioactive compounds for further drug discovery. Novelty impact statement More than 100 compounds have been identified in Moroccan propolis extracts. Trigonelline (an alkaloid) was identified for the first time in propolis. Propolis extracts exhibited strong antibacterial and antioxidant activity.

Kinetic study of the microwave‐induced thermal degradation of cv. Arbequina olive oils flavored with lemon verbena essential oil

AbstractThe effect of typical domestic microwave heating (0–15 min, at 800 W) on the thermal degradation of unflavored and flavored olive oils' minor bioactive compounds and related antioxidant activity was studied. Olive oils from cv. Arbequina were flavored with lemon verbena essential oil (0%, 0.2% and 0.4%, w/w) leading to a linear increase of total phenols (112–160 mg gallic acid kg−1 oil, R‐Pearson = +0.9870), total carotenoids (2.19–2.56 mg lutein kg−1 oil, R‐Pearson = +0.9611), and, to a less extent, of chlorophyll (2.32–3.19 mg pheophytin kg−1 oil, R‐Pearson = +0.8238). However, no such linear trend was observed for the oxidative stability (6.5–7.8 h) or the radical scavenging activity (inhibition rates: 40%–43%). The contents of total phenols, total carotenoids, and chlorophyll decreased with the rise of the microwave heating time, following their thermal degradation, a second‐order kinetic model (0.8784 ≤ R‐Pearson ≤ 0.9926). The essential oil addition did not influence the estimated second‐order rate reaction constants of total phenols (0.00070–0.00072 kg oil min−1 mg−1 gallic acid)and total carotenoids (0.14–0.17 kg oil min−1 mg−1 lutein), with a broader variation observed for chlorophyll (0.014–0.022 kg oil min−1 mg−1 pheophytin). Globally, total carotenoids degraded faster than total phenols and chlorophyll (half‐life of 2.3–3.4, 8.8–12.8, and 14.5–30.8 min, respectively). Moreover, except for chlorophyll, the half‐life of total phenols and carotenoids linearly decreased with the essential oil addition (R‐Pearson: −0.9999 and −0.9421, respectively), showing that flavoring did not have a protective effect against degradation when subjected to a microwave heating.

Structure–antioxidant activity relationships of gallic acid and phloroglucinol

Structure–antioxidant activity relationships of gallic acid and phloroglucinol

Bacterial Inhibition and Antioxidant Activity of Probiotic Yoghurt Developed Using Microbial Isolates from Soymilk

The aim of this study was to investigate the bacterial inhibition and antioxidant activities of probiotic yoghurts developed using microbial isolates from Soymilk. Bacterial inhibitory activity of yoghurt was evaluated against Staphyloccocus aureus, Bacillus subtillis, Escherichia coli and Pseudomonas flourescens by using the disk diffusion method. The yoghurt showed some inhibitory activities against all the organisms tested. Antioxidant activity of yoghurt was measured using three different methods- Diphenyl-1-picryl hydroxyl (DPPH) radical scavenging activity, lipid peroxidase assay and hydroxyl radical scavenging activity against Butylated hydroxyanisole (BHA) as standard. The results showed that probiotic yoghurt exhibits relative high antioxidant activities as compare to BHA. However, by implications this study suggests that probiotic yoghurt has some inhibitory activities against all the bacteria tested, also can be consider among the most promising functional foods for their antioxidant activity and ability to prevent oxidative damage and attendant ageing.

Chemical Composition, Antioxidant, Antimicrobial and Cytotoxic/Cytoprotective Activity of Non-Polar Extracts of Grape (Vitis labrusca cv. Bordeaux) and Blackberry (Rubus fruticosus) Seeds.

The aim of this study was to compare the influence of the extraction method, chemical composition, antimicrobial effects, antioxidant activity, and cytotoxicity on human cells of the non-polar extracts of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. The Soxhlet (Sox), Bligh–Dyer (BD), and ultrasound (US) methods were used for extractions. For blackberry non-polar seed extract, extraction via the BD method showed the highest mean values of total phenolic content (TPC), expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (102.37 mg GAE/100 mL), and higher antioxidant activity in relation to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (11.50 mg AAE/100 mL), if compared with the Sox and US extractions. Similar results were obtained for the non-polar grape seed extracts, where BD extraction obtained the highest values for TPC (28.61 mg GAE/100 mL) and DPPH (35.36 mg AAE/100 mL). The type of extraction method had an impact on the composition of fatty acids. Only the non-polar blackberry and grape seed extracts obtained via the Sox method showed some in vitro inhibitory effect against Escherichia coli (IAL 2064) and Staphylococcus aureus (ATCC 13565). Regardless of the extraction method used, the non-polar blackberry and grape seed extracts did not decrease the cell viability (IC50 >1000 µg/mL) of cancer and normal cell lines, thus indicating the relative safety of the extracts. All the seed extracts decreased the generation of reactive oxygen species in the cell lines. Blackberry and grape seed lipid fractions can be utilized as antioxidants, and the extraction methods used cause significant changes in relation to their bioactivity and chemical composition.

Transforming Growth Factor-β and Oxidative Stress in Cancer: A Crosstalk in Driving Tumor Transformation.

Cancer metabolism involves different changes at a cellular level, and altered metabolic pathways have been demonstrated to be heavily involved in tumorigenesis and invasiveness. A crucial role for oxidative stress in cancer initiation and progression has been demonstrated; redox imbalance, due to aberrant reactive oxygen species (ROS) production or deregulated efficacy of antioxidant systems (superoxide dismutase, catalase, GSH), contributes to tumor initiation and progression of several types of cancer. ROS may modulate cancer cell metabolism by acting as secondary messengers in the signaling pathways (NF-kB, HIF-1α) involved in cellular proliferation and metastasis. It is known that ROS mediate many of the effects of transforming growth factor β (TGF-β), a key cytokine central in tumorigenesis and cancer progression, which in turn can modulate ROS production and the related antioxidant system activity. Thus, ROS synergize with TGF-β in cancer cell metabolism by increasing the redox imbalance in cancer cells and by inducing the epithelial mesenchymal transition (EMT), a crucial event associated with tumor invasiveness and metastases. Taken as a whole, this review is addressed to better understanding this crosstalk between TGF-β and oxidative stress in cancer cell metabolism, in the attempt to improve the pharmacological and therapeutic approach against cancer.

The effects of nanographene oxide on the morpho-biochemical traits and antioxidant activity of Lepidium sativum L. under in vitro salinity stress

Nanographene oxides (NGO) have shown exclusive potential in improving plants defense system mechanisms under various environmental conditions. This study was performed to estimate the potential impact of various NGO concentrations (150, 300, and 450 μg mL−1) on the biochemical and morpho-physiological features of Lepidium sativum L. calli under control and sodium chloride-induced salinity stress conditions. Accordingly, a significant increase was observed in all of the studied biochemical traits of the salinity-treated calli (1.5% w/v NaCl). Moreover, NGO affected the callus related traits, secondary metabolites and enzymatic antioxidant activity under both non-salinity and salinity stress conditions. In this regard, at a concentration of 300 μg mL−1 NGO, the total phenolics content (TPC) (27%), total flavonoids content (TFD) (91%), phenylalanine ammonia lyase (PAL) activity (176%), 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity (140%) and relative callus fresh weight (12%) significantly increased as compared to the salinity stressed NGO-treatment. The highest increase of anthocyanins (Ant) (285%) was observed under the 450 μg mL−1 NGO treatment, as compared to the respective control under salinity stress. However, catalase (CAT) activity and callus growth rate under NGO elicitation significantly decreased as compared to the respective control under salinity stress. Our findings recommended that low to medium concentrations of NGO (150 and 300 μg mL−1) could be applied as novel elicitors to alleviate the negative effects of salinity stresses by increasing phenolics biosynthesis in plants under in vitro conditions.

Do magnetic field applications affect in vitro regeneration, growth, phenolic profiles, antioxidant potential and defense enzyme activities (SOD, CAT and PAL) in lemon balm (Melissa officinalis L.)?

Melissa officinalis L. (lemon balm) is a valuable medicinal plant used in the treatment of nervousness, cardiac failure, hypersensitivities, depression, insomnia, indigestion and colic.Objective of the first part of the study was to determine the effect of 3 different magnetic fields (MF-50 mT, 100 mT and 150 mT) with 5 different exposure times (5 min, 15 min, 30 min, 1 h and 3 h) on in vitro regeneration of explants containing preexisting meristem (axillary, shoot tip and hypocotyl buds). Regenerated shoots were also compared in terms of shoot length, root length, fresh-dry weight and % water content. In the second stage, regenerated shoots obtained from 3 different MF treatments for 1 h and no MF-treated shoots (control) were compared according to their phenolic profile, total phenol-flavonoid content, free radical scavenging activity, superoxide dismutase (SOD), catalase (CAT) and phenylalanine ammonium lyase (PAL) activities. The best regeneration was obtained with axillary buds exposed to 100 mT for 1 h (15.8 shoots at 100 % shoot frequency). Furthermore, 50 mT and 100 mT MF treatments improved the growth parameter and water contents of regenerated shoots. Comparison of 4 different sources (3 MF exposure and no exposure-control) found out that 50 mT MF treatment was the most effective for the enhancement of rosmarinic acid quantity, total phenol-flavonoid content, non-enzymatic antioxidant activity (IC50), stress related enzymatic antioxidant activity (SOD and CAT) and phenol production related PAL enzyme activity. Although 100 mT MF for 1 h treatment was found to be the most potent in regard to number of shoot formation, the most productive shoot length and fresh-dry weight was obtained with 50 mT MF exposure for 1 h. Considering the all results about growth parameters, medicinal quality (rosmarinic acid amount, total phenol-flavonoid content and antioxidant activity) and endurance capacity against stress (SOD, CAT and PAL activities), it can be concluded that exposure to 50 mT MF was the most effective treatment for in vitro culture of M. officinalis.

Target-Mimicry-Based miR167 Diminution Confers Salt-Stress Tolerance During In Vitro Organogenesis of Tobacco (Nicotiana tabacum L.)

In response to environmental and cellular cues, the spatiotemporal expression of differentially expressed miRNAs (DEmiRs) during in vitro regeneration of plants is prominent. Nevertheless, the influence of stress conditions on the functional imprints of DEmiRs during plant organogenesis is inadequately understood. Target-mimicry based constitutive diminution of miR167 genes in transgenic tobacco revealed their functional contributions in salt-stress tolerance during organogenesis. Up to 61.6% relative increment in the shoot emergence on leaf explants of miR167 mimic lines (cultured on 12.5 and 25 mM NaCl concentrations) exhibited greater magnitude of organogenesis under stress, most probably through upregulated auxin signalling. Relative expression analysis of auxin transporter genes AUX1, PIN1 and PIN2 revealed synergistic effect of percent miR167 diminution and salt-stress (up to 12.5 mM) resulting into enhanced callogenesis and reduced organogenesis. Biochemical assessment of in vitro grown miR167 mimic shoot initials revealed an increase in the relative water content, chlorophyll and antioxidant activity, which suggested a shift in the molecular equilibrium in response to miR167 diminution-associated signalling pathways. Remarkably, independent miR167 diminution lines exhibited expression variations among associated miR156, miR159, and miR394 and validated by the expression analysis of selected target genes SPL9, ARF6 and ARF8. The expression ratios of these miRNAs revealed their coordinated regulatory network in response to salt-stress during organogenesis. These results demonstrate a link between miR167 diminution and salt-stress tolerance in mimic lines, and suggest that a regulatory shift in the cellular metabolism may contribute to salt-stress tolerance in plants. These observations may create new avenues for strategic utilization of such genic resources for future crop research.

PHYTOCHEMICAL INVESTIGATION AND ANTIOXIDANT ACTIVITY OF EXTRACTS OF SOME MEDICINAL PLANTS

In current study, we accepted out a systematic record of the relative antioxidant activity in selected medicinal plant species extracts. The total phenol varied from 25.3±7 to 278.4±7 mg g-1 in the extracts. Flavonoid contents were between 56±4.4 and 80.3±3.7. 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging result of the extracts was determined spectrophotometrically. The maximum radical scavenging consequence was observed in Metha pulegiam (Lamiacea) with IC50 = 0.018 mg ml-1. The strength of radical scavenging power of Metha pulegiam extract was about 4 times better than synthetic antioxidant butylated hydroxy toluene (BHT). The superior amount of phenolic compounds leads to further potent radical scavenging result as shown by Metha pulegiam leaves extract.

DFT study of the radical scavenging activity of isoxanthohumol, humulones (α-acids), and iso-α-acids from beer

Humulones and iso-humulones are potent natural antioxidants found in beer. In this study, density functional theory (DFT) method was applied for elucidating the structure-antioxidant activity relationship and molecular mechanism of antioxidant activity of eight bioactive humulones previously identified in different beer samples: isoxanthohumol, (R)- and (S)-adhumulone, cis- and trans-iso-adhumulone, cis- and trans-iso-n-humulone, and desdimethyl-octahydro-iso-cohumulone. The calculated bond dissociation enthalpies (BDEs) suggest that desdimethyl-octahydro-iso-cohumulone was the most potent compound with BDEs 5.1 and 23.9 kJ/mol lower compared to the values for resveratrol in gas phase and water, respectively. The enolic –OH is the most reactive site for hydrogen atom transfer (HAT). The presence of β-keto group with respect to enolic –OH diminishes the HAT potency via the formation of a strong intramolecular hydrogen bond. Another common antioxidant mechanism, single electron transfer followed by proton transfer (SET-PT), is only feasible for isoxanthohumol. The results of this study indicate a strong correlation between the increased antioxidant activity of beer products and the higher content of reduced iso-α-acids.

In Silico and In Vitro Evaluation of the Antimicrobial and Antioxidant Potential of Mentha × smithiana R. GRAHAM Essential Oil from Western Romania.

This study was conducted to identify the volatile compounds of Mentha × smithiana essential oil (MSEO) and evaluate its antioxidant and antibacterial potential. The essential oil (EO) content was assessed by gas chromatography–mass spectrometry (GC-MS). Carvone (55.71%), limonene (18.83%), trans-carveol (3.54%), cis-carveol (2.72%), beta-bourbonene (1.94%), and caryophyllene oxide (1.59%) were the main identified compounds. The MSEO displayed broad-spectrum antibacterial effects and was also found to be the most effective antifungal agent against Candida albicans and Candida parapsilosis. The antioxidant activity of MSEO was tested against cold-pressed sunflower oil by peroxide, thiobarbituric acid, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and β-carotene/linoleic acid bleaching methods. The EO showed strong antioxidant effects as reflected by IC50 values of 0.83 ± 0.01 mg/mL and relative antioxidative activity of 87.32 ± 0.03% in DPPH and β-carotene/linoleic acid bleaching assays, respectively. Moreover, in the first 8 days of the incubation period, the inhibition of primary and secondary oxidation compounds induced by the MSEO (0.3 mg/mL) was significantly stronger (p < 0.05) than that of butylated hydroxyanisole. In silico molecular docking studies were conducted to highlight the underlying antimicrobial mechanism as well as the in vitro antioxidant potential. Recorded data showed that the antimicrobial activity of MSEO compounds could be exerted through the D-Alanine-d-alanine ligase (DDl) inhibition and may be attributed to a cumulative effect. The most active compounds are minor components of the MSEO. Docking results also revealed that several mint EO components could exert their in vitro antioxidant activity by employing xanthine oxidase inhibition. Consequently, MSEO could be a new natural source of antioxidants and antiseptics, with potential applications in the food and pharmaceutical industries as an alternative to the utilization of synthetic additives.

In Vitro Gastrointestinal Digestion Impact on the Bioaccessibility and Antioxidant Capacity of Bioactive Compounds from Tomato Flours Obtained after Conventional and Ohmic Heating Extraction.

In times of pandemic and when sustainability is in vogue, the use of byproducts, such as fiber-rich tomato byproducts, can be an asset. There are still no studies on the impact of extraction methodologies and the gastrointestinal tract action on bioactive properties. Thus, this study used a solid fraction obtained after the conventional method (SFCONV) and a solid fraction after the ohmic method (SFOH) to analyze the effect of the gastrointestinal tract on bioactive compounds (BC) and bioactivities. Results showed that the SFOH presents higher total fiber than SFCONV samples, 62.47 ± 1.24–59.06 ± 0.67 g/100 g DW, respectively. Both flours present high amounts of resistant protein, representing between 11 and 16% of insoluble dietary fiber. Furthermore, concerning the total and bound phenolic compounds, the related antioxidant activity measured by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolorization assay presented significantly higher values for SFCONV than SFOH samples (p < 0.05). The main phenolic compounds identified in the two flours were gallic acid, rutin, and p-coumaric acid, and carotenoids were lycopene, phytofluene, and lutein, all known as health promoters. Despite the higher initial values of SFCONV polyphenols and carotenoids, these BCs’ OH flours were more bioaccessible and presented more antioxidant capacity than SFCONV flours, throughout the simulated gastrointestinal tract. These results confirm the potential of ohmic heating to modify the bioaccessibility of tomato BC, enhancing their concentrations and improving their antioxidant capacity.

Stevia rebaudiana (Bertoni) as a Multifunctional and Sustainable Crop for the Mediterranean Climate

Stevia rebaudiana (Bertoni) is a promising medicinal and aromatic plant for Mediterranean agroecosystems given its positive agronomic attributes and interesting quality features. It has both food and pharmaceutical applications, since its leaves contain sweet-tasting steviol glycosides (SVglys) and bioactive compounds, such as phenolics, flavonoids, and vitamins. We evaluated the agronomic and qualitative performances of nine stevia genotypes cultivated, in open field conditions, for two consecutive years under the Mediterranean climate of central Italy. Growth, biomass production, and accumulation of bioactive compounds (SVglys, polyphenols, and their related antioxidant activities) were evaluated, considering the effect of harvest time and crop age (first and second year of cultivation). The results showed high variability among genotypes in terms of both morpho-productive and phytochemical characteristics. In general, greater leaf dry yields, polyphenol accumulation, and antioxidant activities were found in the second year of cultivation, harvesting the plants in full vegetative growth. On the other hand, total SVglys leaf content reached the highest values in the first year when plants were at the beginning of the reproductive phase. On the other hand, although the SVglys profile (Rubusoside, Dulcoside A, Stevioside, Rebaudioside A, C, D, E, and M) remained stable over harvest times, it differed significantly depending on the crop age and genotype. Our findings provide useful information on the influence of crop age and harvest time in defining quanti-qualitative traits in stevia, with PL, SL, BR5, and SW30 being the best performing genotypes and thus suitable for breeding programs. Our study highlighted that stevia, in the tested environment, represents a promising semi-perennial crop which offers new solutions in terms of cropping system diversification and marketing opportunities.

Probiotic Fermentation of Konjac and Carob Pods Ceratonia siliqua and Observation of Related Antioxidant Activity

Probiotic Fermentation of Konjac and Carob Pods Ceratonia siliqua and Observation of Related Antioxidant Activity

Comparative Study of Early- and Mid-Ripening Peach (Prunus persica L.) Varieties: Biological Activity, Macro-, and Micro- Nutrient Profile.

Exploring the chemical composition and biological activity of different fruit varieties is essential for the valorization of their health claims. The current study focuses on a detailed comparative analysis of three early- and two mid-ripening peach varieties: “Filina” (peach), “July Lady” (peach), “Laskava” (peach), “Gergana” (nectarine), and “Ufo 4” (flat peach). They were characterized in terms of essential nutrients such as carbohydrates (sugars and dietary fibers), amino acid content, and lipids as well as mineral content, fat-soluble vitamins, carotenoids, and chlorophyll. Polyphenolic compounds and the related antioxidant activity were also assessed. The methanolic extract of the peel seems to be richer in the studied biologically active substances compared to the fleshy part of the fruit. Anthocyanins were most abundant in “Gergana” and “July Lady” extracts (6624.8 ± 404.9 and 7133.6 ± 388.8 µg cyanidin-3-glucoside/100 g fw, resp.). The total phenol content of the samples varied from 34.11 ± 0.54 to 157.97 ± 0.67 mg gallic acid equivalents (GAE)/100 g fw. “Filina” and “July Lady” varieties possessed the highest antioxidant activity. Overall, the results of this study confirm that the studied peach varieties have satisfactory nutritional value and are potential sources of biologically active substances. Each variety represents an individual palette of nutrients that should be considered separately from the other.

QSAR Assessing the Efficiency of Antioxidants in the Termination of Radical-Chain Oxidation Processes of Organic Compounds.

Using the GUSAR 2013 program, the quantitative structure–antioxidant activity relationship has been studied for 74 phenols, aminophenols, aromatic amines and uracils having lgk7 = 0.01–6.65 (where k7 is the rate constant for the reaction of antioxidants with peroxyl radicals generated upon oxidation). Based on the atomic descriptors (Quantitative Neighborhood of Atoms (QNA) and Multilevel Neighborhoods of Atoms (MNA)) and molecular (topological length, topological volume and lipophilicity) descriptors, we have developed 9 statistically significant QSAR consensus models that demonstrate high accuracy in predicting the lgk7 values for the compounds of training sets and appropriately predict lgk7 for the test samples. Moderate predictive power of these models is demonstrated using metrics of two categories: (1) based on the determination coefficients R2 (R2TSi, R20, Q2(F1), Q2(F2), ) and based on the concordance correlation coefficient (CCC)); or (2) based on the prediction lgk7 errors (root mean square error (RMSEP), mean absolute error (MAE) and standard deviation (S.D.)) The RBF-SCR method has been used for selecting the descriptors. Our theoretical prognosis of the lgk7 for 8-PPDA, a known antioxidant, based on the consensus models well agrees with the experimental value measure in the present work. Thus, the algorithms for calculating the descriptors implemented in the GUSAR 2013 program allow simulating kinetic parameters of the reactions underling the liquid-phase oxidation of hydrocarbons.