Use of liquid chromatography with electrochemical detection for the determination of antioxidants in less common fruits

Assessment of Biochemical Composition of Fruits of Hippophae rhamnoides (Elaeagnaceae juss.), Viburnum opulus (Viburnaceae raf.) and Lonicera caerulea subsp. altaica (Caprifoliaceae juss.)

Background/Objectives: This study explores the biochemical diversity of Hippophae rhamnoides, Viburnum opulus, and Lonicera caerulea subsp. altaica to identify genotypes rich in bioactive compounds for breeding nutritionally valuable cultivars. Methods: Selected forms and cultivars of each species were evaluated for key biochemical traits. Analyses included quantification of vitamins (C, B9, B12), sugars, organic acids, carotenoids, and flavonoids using HPLC and TLC. Results: In H. rhamnoides, vitamin C content ranged widely, with 'Pamyati Baytulina Sh-9-81' reaching 156.0 mg/%, while 'Shetlastinka No. 7' showed the most favorable sugar-to-vitamin C ratio. 'Krasnoplodnaya K-14-81' had the highest carotenoids (55.3 mg/100 g), and 'Dolgozhdannaya No. 5' was notable for flavonoid richness. In V. opulus, considerable variation was observed in vitamin content, sugars, and dry matter; 'Zhemchuzhnoe Ozhele' and 'Shtambovaya' were rich in rutin and robinin. In L. caerulea subsp. altaica, forms No. 5, 7, and 9 stood out for vitamin C, sugar, and flavonoid content. Hyperoside, isorhamnetin, and myricetin were common, while kaempferol and hypolaetin were form-specific. Conclusions:H. rhamnoides demonstrated the highest variability in biochemical composition, while L. caerulea subsp. altaica showed a particularly rich flavonoid profile. These species offer valuable genetic resources for developing biofortified cultivars suited to both nutritional and adaptive breeding goals.

Phytochemical screening, HPLC fingerprinting and in vitro assessment of therapeutic potentials of different apricot cultivars against diabetes, Alzheimer's disease and cancer

Plant-based natural compounds are widely used to treat various ailments owing to their readily availability and minimal adverse effects. This study aimed to perform qualitative and quantitative biochemical profiling and assess the in vitro anti-diabetic, anti-Alzheimer, and anti-cancer activities of various apricot (Prunus armeniaca) cultivars. High-performance liquid chromatography (HPLC) was utilized to determine the concentrations of bioactive compounds across 10 distinct apricot cultivars. Initial phytochemical screening revealed a significant content of secondary metabolites. Subsequently, methanolic extracts from these cultivars were evaluated for their therapeutic potential against several human cancer cell lines, including prostate cancer (PC-3), lung cancer (A-549), breast cancer (MCF-7), cervical cancer (HELA), and kidney cancer (HEK). Notably, the breast cancer cell line MCF-7 showed a pronounced inhibition rate post-treatment with the apricot extracts. Correlation analysis exhibited phenols are highly correlated with flavonoids (r = 0.92), DPPH (r = 0.95), and alpha-amylase (%) inhibition (r = 0.96), and showed a significant correlation with other parameters. Principal Component Analysis (PCA) revealed that PC1 explained 43.31 % of the variance, while PC2 explained 12.88 %, together explaining 80.033 % of the total variance. PC1 was identified as the dominant axis, indicating the primary pattern of variation among the variables. Hierarchical Cluster Analysis (HCA) divided the cultivars into 2 main clusters, with cluster 2 further subdivided into various sub-clusters and sub-sub-clusters. This analysis highlighted distinct genetic similarities and differences among the apricot cultivars. Among the tested cultivars, 'Irani' and 'Tilton' were found to contain the highest levels of bioactive constituents. This research marks the first comprehensive examination of the impacts of these two apricot cultivars. The findings from this study provide a robust scientific foundation for the future isolation and purification of therapeutic compounds, potentially leading to their application in pharmaceuticals or dietary supplements. This research contributes significantly to the understanding of the pharmacological properties of apricot cultivars and establishes a basis for further investigation into their clinical benefits.

Botany, traditional uses, phytochemistry and pharmacological activity of Crataegus pinnatifida (Chinese hawthorn): a review

OBJECTIVES

Crataegus pinnatifida (C. pinnatifida), including C. pinnatifida Bge. and its variant C. pinnatifida Bge. var. major N, E. Br., has traditionally been used as a homologous plant for traditional medicine and food in ethnic medical systems in China. Crataegus pinnatifida, especially its fruit, has been used for more than 2000 years to treat indigestion, stagnation of meat, hyperlipidemia, blood stasis, heart tingling, sores, etc. This review aimed to provide a systematic summary on the botany, traditional uses, phytochemistry, pharmacology and clinical applications of C. pinnatifida.

KEY FINDINGS

This plant contains flavonoids, phenylpropanoids, terpenoids, organic acids, saccharides and essential oils. Experimental studies showed that it has hypolipidemic, antimyocardial, anti-ischemia, antithrombotic, anti-atherosclerotic, anti-inflammatory, antineoplastic neuroprotective activity, etc. Importantly, it has good effects in treating diseases of the digestive system and cardiovascular and cerebrovascular systems.

SUMMARY

There is convincing evidence from both in vitro and in vivo studies supporting the traditional uses of C. pinnatifida. However, multitarget network pharmacology and molecular docking technology should be used to study the interaction between the active ingredients and targets of C. pinnatifida. Furthermore, exploring the synergy of C. pinnatifida with other Chinese medicines to provide new understanding of complex diseases may be a promising strategy.

Effect of Aronia Extract on Collagen Synthesis in Human Skin Cell and Dermal Equivalent

The regulation of collagen synthesis, which occurs in fibroblasts in the dermal layer, is a key process in dermis regeneration and skin reconstruction. Herein, we investigated whether Aronia melanocarpa extract affects the human skin condition. We focused on type I collagen synthesis using two different types of model systems: a monolayer of cells and a bioprinted 3D dermal equivalent. The Aronia extract showed no cytotoxicity and increased cell proliferation in neonatal human dermal fibroblasts. Treatment with Aronia extract increased the transcription of COL1A1 mRNA in direct proportion to the extract concentration without causing a decrease in COL1A1 mRNA degradation. Additionally, the Aronia extract inhibited the expression of MMP1 and MMP3, and an increase in type I collagen was observed along with a decrease in MMP1 protein. We also fabricated dermal equivalents from type I collagen (the major component of the dermis) and dermal fibroblasts by bioprinting. In the 3D dermis model, the compressive modulus directly affected by collagen synthesis increased in direct proportion to the Aronia extract concentration, and expression levels of MMP1 and MMP3 decreased in exactly inverse proportion to its concentration. The findings that the Aronia extract increases synthesis of type I collagen and decreases MMP1 and MMP3 expression suggest that this extract may be useful for the treatment of damaged or aged skin.

Temperature Optimization by Electrochemical Method for Improving Antioxidant Compound Extraction Efficiency from Origanum vulgare L. and Its Application in a Bread Production

This study aims to evaluate the effect of extraction temperature on the electrochemical activity of antioxidant compounds in oregano extract and its application in a bread production. Temperature optimisation was performed by determining the electrochemical index (EI), calculated on the parameters of individual peaks observed on the square wave voltammograms (SWV). The highest value of EI (2.5758 µA/V) was observed at 85 °C for the oregano extract. The composition of several types of bread with oregano extract or dried oregano leaves was then proposed. To specify bread samples, both newly prepared and during their storage, their antioxidant properties were determined using FRAP (Ferric Reducing Antioxidant Power) and CUPRAC (Cupric Reducing Antioxidant Capacity) methods. The study revealed that the addition of extract from oregano or oregano leaves increased the antioxidant compounds content in the bread from 30% to more than 138% compared to the control bread samples. The performed sensory evaluation of the bread samples revealed their high acceptability. It was found that the stored bread with oregano leaves changed sensory qualities to a lesser extent compared to the bread with oregano extract.

Application of Blue Honeysuckle Powder Obtained by an Innovative Method of Low-Temperature Drying in Skincare Face Masks

Traditional technologies applied for obtaining plant raw materials for cosmetic production are based primarily on high-level processing, which is reflected in the qualitative composition of the resulting materials. By using low-temperature drying, it is possible to retain in the raw materials a range of valuable ingredients. In this study, blue honeysuckle powder was used as an ingredient of cosmetic face masks. The stability of the masks was evaluated. Dynamic viscosity, yield point and texture analysis of the cosmetics was performed. The color of the emulsions and the level of skin hydration after face mask application was determined. Emulsions were found to be stable. A decrease in dynamic viscosity of the emulsions as a function of increasing concentrations of the additive and under the conditions of rising rotational speed were observed. Similarly, an increase in the concentration of blue honeysuckle in the emulsions resulted in a decrease in the value of the yield point. Based on the results, it can be stated that the addition of blue honeysuckle caused a decrease in hardness of the masks, while the opposite trend was observed for adhesive force. It was found that an increase in the concentration of blue honeysuckle gave a reddish-yellow color to the samples. Corneometric assessment confirmed proper skin hydration after the application of the emulsions.

Evaluation of genetic diversity of edible honeysuckle monitored by RAPD in relation to bioactive substances

The aim of this study was clarifying the relation between genetic diversity of edible honeysuckle (Lonicera kamtschatica) and the major group of biologically active substances as total polyphenols content (TPC) including antioxidant activity (AO). Fruits of edible honeysuckle becomes more and more popular, especially in Europe. The current status of research on polyphenolic compounds in the berries of edible honeysuckle and their biological effects, including recommended utilization, are reviewed.The biological material including 14 cultivars of the edible honeysuckle (´Zoluška´, ´Amfora´, ´Pruhonický 44´, ´Vasilijevsky´, ´Moskovskaja´, ´Vojtek´, ´Sinoglaska´, ´Altaj´, ´Lipnická´, ´Kamčadalka´, ´Sinaja Ptica´, ´Fialka´, ´Modrý Triumf´, and ´Leningradský velikán´) originated from Czech republic (Žabcice near Brno). The content of TPC and AO were determined by location and its soil-climatic conditions and these environmental circumstances determines the RAPD profiles of analysed honeysuckle acessions, too. DPPH method was used to analyze AO and Folin-Ciocalteu method was used to determine TPC. The results of experiment showed that the highest value of AO was determined at the cultivars ´Zoluška´ (81.04 mg.L-1) and the lowest was measured in ´Kamčadalka´ (54.122 mg.L-1).  On the contrary, the highest content of TPC was determined at the cultivar ´Kamčadalka´ (51.09 mg.L-1) and the lowest value was measured at the cultivar ´Pruhonický 44´ (21.65 mg.L-1). Phylogenetic trees were similar in genetic distance. The  content of TPC and AO were  not statistically significant in relation to cultivar. The analyzed cultivars of the edible honeysuckle were separated in 4 clusters according to used primers. In both  gel images, the amplicon size ranged from 100 to 1,500 bp. We found that genetic diversity was partially related to content of total polyphenolic substances and antioxidant activity. Based on phylogenetic trees we have stated that variety ´Lipnická´, ´Sinoglaska´, ´Altaj´, ´Leningradský velikán´, ´Modrý Triumf´, ´Sinaja Ptica´ and ´Kamčadalka´ were grouped in the similar cluster. The highest genetic distance was determined at the variety ´Vasilijevskaja´ and ´Amfora´. In the same way, there were variety ´Vojtek´, ´Fialka´ and ´Zoluška´.

Fruits of Black Chokeberry Aronia melanocarpa in the Prevention of Chronic Diseases

In recent years, growing attention has been focused on the utilization of natural sources of antioxidants in the prevention of chronic diseases. Black chokeberry (Aronia melanocarpa) represents a lesser known fruit species utilized mainly as juices, purees, jams, jellies and wine, as important food colorants or nutritional supplements. The fruit is valued as a great source of antioxidants, especially polyphenols, such as phenolic acids (neochlorogenic and chlorogenic acids) and flavonoids (anthocyanins, proanthocyanidins, flavanols and flavonols), particularly cyanidin-3-galactoside and cyanidin-3-arabinoside, as well as (-)-epicatechin units. The berries of A. melanocarpa, due to the presence and the high content of these bioactive components, exhibit a wide range of positive effects, such as strong antioxidant activity and potential medicinal and therapeutic benefits (gastroprotective, hepatoprotective, antiproliferative or anti-inflammatory activities). They could be also contributory toward the prevention of chronic diseases including metabolic disorders, diabetes and cardiovascular diseases, because of supportive impacts on lipid profiles, fasting plasma glucose and blood pressure levels.

Black Crowberry (Empetrum nigrum L.) Flavonoids and Their Health Promoting Activity

Nowadays, much research attention is focused on underutilized berry crops due to the high antioxidant activity of fruits. Black crowberry (Empetrum nigrum L.) represents an important source of flavonols (quercetin, rutin, myricetin, naringenin, naringin, morin, and kaempferol) and anthocyanins. The fruit components could be utilised as natural colourants or as a part of functional foods and, because of the high antioxidant activity, the berries of black crowberry can be used in the treatment of diseases accompanied with inflammation, or as an effective antibacterial and antifungal remedy. Moreover, the reduction of lipid accumulation and total cholesterol as well as an improvement of postprandial hyperglycaemia have been proven. This review summarizes for the first time the main antioxidants (flavonoids) of black crowberry fruits, with a focus on their health promoting activity.

Quercetin and Its Anti-Allergic Immune Response

Quercetin is the great representative of polyphenols, flavonoids subgroup, flavonols. Its main natural sources in foods are vegetables such as onions, the most studied quercetin containing foods, and broccoli; fruits (apples, berry crops, and grapes); some herbs; tea; and wine. Quercetin is known for its antioxidant activity in radical scavenging and anti-allergic properties characterized by stimulation of immune system, antiviral activity, inhibition of histamine release, decrease in pro-inflammatory cytokines, leukotrienes creation, and suppresses interleukin IL-4 production. It can improve the Th1/Th2 balance, and restrain antigen-specific IgE antibody formation. It is also effective in the inhibition of enzymes such as lipoxygenase, eosinophil and peroxidase and the suppression of inflammatory mediators. All mentioned mechanisms of action contribute to the anti-inflammatory and immunomodulating properties of quercetin that can be effectively utilized in treatment of late-phase, and late-late-phase bronchial asthma responses, allergic rhinitis and restricted peanut-induced anaphylactic reactions. Plant extract of quercetin is the main ingredient of many potential anti-allergic drugs, supplements and enriched products, which is more competent in inhibiting of IL-8 than cromolyn (anti-allergic drug disodium cromoglycate) and suppresses IL-6 and cytosolic calcium level increase.

Optimization of ultrasound-assisted extraction of anthocyanins from haskap berries (Lonicera caerulea L.) using Response Surface Methodology

Haskap berries (Lonicera caerulea L.) are a rich source of bioactive molecules. As such, the extraction of anthocyanins is important for the development of many value-added products and functional food ingredients. In this paper, the ultrasound-assisted extraction (UAE) of anthocyanins from haskap berries was investigated. Significant independent variables were screened and optimized using Plackett-Burman (PB) and Box-Behnken (BB) designs, respectively. The mathematical model showed a high coefficient of determination (R(2)=0.9396) and the optimum conditions for the extraction were as follows: liquid/solid ratio 25:1 (mL/g), solvent composition of 80% ethanol, addition of 0.5% formic acid, ultrasound bath temperature of 35°C for 20 min. Under these conditions, the total anthocyanin content of 22.73 mg cyaniding 3-glucoside equivalents (C3G)/g dry weight (DW) was consistent with the predicted response of 22.45 mg C3G/g DW from the model (mean error of 1.28%). Five anthocyanins were identified in the optimized extract, namely cyanidin 3,5-diglucoside, cyanidin 3-glucoside, cyanidin 3-rutinoside, pelargonidin 3-glucoside, and peonidin 3-glucoside. Thus, UAE is a suitable technique for the extraction of anthocyanins from haskap berries.

Evaluation of antioxidant activity, polyphenolic compounds, amino acids and mineral elements of representative genotypes of Lonicera edulis

The aim of this study was to evaluate the bioactive substances in 19 berry cultivars of edible honeysuckle (Loniceraedulis). A statistical evaluation was used to determine the relationship between the content of selected bioactive substances and individual cultivars. Regarding mineral elements, the content of sodium was measured using potentiometry and spectrophotometry. The content of selected polyphenolic compounds with high antioxidant activity was determined by a HPLC–UV/ED method. The total amount of polyphenols was determined by the Folin-Ciocalteu method. The antioxidant activity was determined using five methods (DPPH, FRAP, ABTS, FR and DMPD) that differ in their principles. The content of 13 amino acids was determined by ion-exchange chromatography. The experimental results obtained for the different cultivars were evaluated and compared by statistical and bioinformatic methods. A unique feature of this study lies in the exhaustive analysis of the chosen parameters (amino acids, mineral elements, polyphenolic compounds and antioxidant activity) during one growing season.

Flavonoid profile of Saskatoon berries (Amelanchier alnifolia Nutt.) and their health promoting effects

Flavonoids are a significant group of secondary metabolites in plants. Many of these compounds are potent antioxidants, being an important part in food products derived from the plants. The current status of research on flavonoid compounds in the fruit of Saskatoon berries (Amelanchier alnifolia Nutt.) and their health promoting effects, including recommended utilization, are reviewed. The major classes of flavonoids in the fruit are flavonols (quercetin and rutin), flavanes (proanthocyanidin compounds ranging from dimers through to heptamers and even higher polymers) and finally anthocyanins. The flavonoids represented the group of polyphenols that mostly contributed to the antioxidant activity of Saskatoon berries. High content of the flavoinoids antioxidants in the fruit is responsible for the observed anti-inflammatory, antidiadiabetic and chemo-protective effects.

Polyphenolic profile and biological activity of Chinese hawthorn (Crataegus pinnatifida BUNGE) fruits

Chinese hawthorn (Crataegus pinnatifida Bge.) fruits are rich in polyphenols (e.g., epicatechin, procyanidin B2, procyanidin B5, procyanidin C1, hyperoside, isoquercitrin and chlorogenic acid)—active compounds that exert beneficial effects. This review summarizes all information available on polyphenolic content and methods for their quantification in Chinese hawthorn berries and the relationships between individual polyphenolic compounds as well. The influence of species or cultivars, the locality of cultivation, the stage of maturity, and extract preparation conditions on the polyphenolic content were discussed as well. Currently, only fruits of C. pinnatifida and C. pinnatifida var. major are included in the Chinese Pharmacopoeia. Recent trials have demonstrated the efficacy of Chinese hawthorn fruit in lowering blood cholesterol and the risk of cardiovascular diseases. The fruit has also demonstrated anti-inflammatory and anti-tumour activities. This review deals mainly with the biological activity of the fruit related to its antioxidant properties.

Evaluation of polyphenolic profile and nutritional value of non-traditional fruit species in the Czech Republic--a comparative study

Dry matter, organic acids, ascorbic acid, minerals (nitrogen, phosphorus, potassium, calcium, magnesium, sodium) and polyphenolic profile of a number of non-traditional fruit species and their genotypes, namely blue honeysuckle (Lonicera spp.), Saskatoon berry (Amelanchier alnifolia), black mulberry (Morus nigra), Tomentosa cherry (Prunus tomentosa Thunb.) and jostaberry (Ribes nigrum x Grossularia uva-crispa) were investigated. The results showed that Lonicera genotypes displayed high levels of ascorbic acid and they were rich in minerals, with the cultivar ‘Amfora’ achieving the leading position in nitrogen, phosphorus and potassium content among all lesser known fruit species. Amelanchier cultivars represented a valuable source of ascorbic acid and calcium, ‘Tišňovský’ and ‘Smoky’ together with Morus nigra ‘Jugoslavska’ accumulated the highest level of examined polyphenolic compounds. Regular consumption of studied less common fruit species can bring health benefits so they can represent a high potential value for fruit growers and in addition they can be utilised as functional foods.

Phenolic profile of edible honeysuckle berries (genus lonicera) and their biological effects

The current status of research on polyphenolic compounds in the berries of edible honeysuckle and their biological effects, including recommended utilization, are reviewed. The major classes of phenolic compounds in the blue berried honeysuckle are flavonols (quercetin, rutin, quercitrin) and flavanes (proanthocyanidins, catechins) and anthocyanins. Cyanidin-3-glucoside and cyanidin-3-rutinoside are considered as major anthocyanidins in edible honeysuckle berries. Such a high level of antioxidant activity in the berries of different species of the genus Lonicera is especially due to the high level of polyphenolic compounds, especially anthocyanins. These berries seem to be prospective sources of health-supporting phytochemicals that exhibit beneficial anti-adherence and chemo-protective activities, thus they may provide protection against a number of chronic conditions, e.g., cancer, diabetes mellitus, tumour growth or cardiovascular and neurodegenerative diseases.

Mathematical evaluation of the amino acid and polyphenol content and antioxidant activities of fruits from different apricot cultivars

Functional foods are of interest because of their significant effects on human health, which can be connected with the presence of some biologically important compounds. In this study, we carried out complex analysis of 239 apricot cultivars (Prunus armeniaca L.) cultivated in Lednice (climatic area T4), South Moravia, Czech Republic. Almost all previously published studies have focused only on analysis of certain parameters. However, we focused on detection both primary and secondary metabolites in a selection of apricot cultivars with respect to their biological activity. The contents of thirteen biogenic alpha-L-amino acids (arginine, asparagine, isoleucine, lysine, serine, threonine, valine, leucine, phenylalanine, tryptophan, tyrosine, proline and alanine) were determined using ion exchange chromatography with UV-Vis spectrometry detection. Profile of polyphenols, measured as content of ten polyphenols with significant antioxidant properties (gallic acid, procatechinic acid, p-aminobenzoic acid, chlorogenic acid, caffeic acid, vanillin, p-coumaric acid, rutin, ferrulic acid and quercetrin), was determined by high performance liquid chromatography with spectrometric/electrochemical detection. Moreover, content of total phenolics was determined spectrophotometrically using the Folin-Ciocalteu method. Antioxidant activity was determined using five independent spectrophotometric methods: DPPH assay, DMPD method, ABTS method, FRAP and Free Radicals methods. Considering the complexity of the obtained data, they were processed and correlated using bioinformatics techniques (cluster analysis, principal component analysis). The studied apricot cultivars were clustered according to their common biochemical properties, which has not been done before. The observed similarities and differences were discussed.

Comparative analysis of radical scavenging and antioxidant activity of phenolic compounds present in everyday use spice plants by means of spectrophotometric and chromatographic methods

Comparative analysis of radical scavenging and antioxidant activities of phenolic compounds present in everyday use spice plants was carried out by means of spectrophotometric and chromatographic methods. Six spice plant samples, namely onion (Allium cepa), parsley (Petroselinum crispum) roots and leaves, celery (Apium graveolens) roots and leaves and leaves of dill (Anethum graveolens) were analyzed. Total amount of phenolic compounds and radical scavenging activity (RSA) was the highest in celery leaves and dill extracts and was the lowest in celery roots. Comparing commonly used spectrophotometric analysis of 2,2-diphenyl-1-picrylhydrazyl (DPPH) RSA of extracts with the results obtained using reversed-phase chromatographic separation with on-line post-column radical scavenging reaction detection, good correlation was obtained (R(2)=0.848). Studies using HPLC system with electrochemical detector showed that bioactive phytochemicals can be separated and antioxidant activities of individual compounds evaluated without the need of a complex HPLC system with reaction detector. The results obtained using electrochemical detection correlate with the RSA assayed using spectrophotometric method (R(2)=0.893).

Fully automated spectrometric protocols for determination of antioxidant activity: advantages and disadvantages

The aim of this study was to describe behaviour, kinetics, time courses and limitations of the six different fully automated spectrometric methods - DPPH, TEAC, FRAP, DMPD, Free Radicals and Blue CrO₅. Absorption curves were measured and absorbance maxima were found. All methods were calibrated using the standard compounds Trolox^® and/or gallic acid. Calibration curves were determined (relative standard deviation was within the range from 1.5 to 2.5 %). The obtained characteristics were compared and discussed. Moreover, the data obtained were applied to optimize and to automate all mentioned protocols. Automatic analyzer allowed us to analyse simultaneously larger set of samples, to decrease the measurement time, to eliminate the errors and to provide data of higher quality in comparison to manual analysis. The total time of analysis for one sample was decreased to 10 min for all six methods. In contrary, the total time of manual spectrometric determination was approximately 120 min. The obtained data provided good correlations between studied methods (R = 0.97 – 0.99).

Content of phenolic compounds and antioxidant capacity in fruits of apricot genotypes

Research on natural compounds is increasingly focused on their effects on human health. In this study, we were interested in the evaluation of nutritional value expressed as content of total phenolic compounds and antioxidant capacity of new apricot (Prunus armeniaca L.) genotypes resistant against Plum pox virus (PPV) cultivated on Department of Fruit Growing of Mendel University in Brno. Fruits of twenty one apricot genotypes were collected at the onset of consumption ripeness. Antioxidant capacities of the genotypes were determined spectrometrically using DPPH• (1,1-diphenyl-2-picryl-hydrazyl free radicals) scavenging test, TEAC (Trolox Equivalent Antioxidant Capacity), and FRAP (Ferric Reducing Antioxidant Power)methods. The highest antioxidant capacities were determined in the genotypes LE-3228 and LE-2527, the lowest ones in the LE-985 and LE-994 genotypes. Moreover, close correlation (r = 0.964) was determined between the TEAC and DPPH assays. Based on the antioxidant capacity and total polyphenols content, a clump analysis dendrogram of the monitored apricot genotypes was constructed. In addition, we optimized high performance liquid chromatography coupled with tandem electrochemical and spectrometric detection and determined phenolic profile consisting of the following fifteen phenolic compounds: gallic acid, 4-aminobenzoic acid, chlorogenic acid, ferulic acid, caffeic acid, procatechin, salicylic acid, p-coumaric acid, the flavonols quercetin and quercitrin, the flavonol glycoside rutin, resveratrol, vanillin, and the isomers epicatechin, (-)- and (+)- catechin.

Phytohormones as important biologically active molecules--their simple simultaneous detection

Phytohormones, their functions, synthesis and effects, are of great interest. To study them in plant tissues accurate and sensitive methods are required. In the present study we aimed at optimizing experimental conditions to separate and determine not only plant hormones but also their metabolites, by liquid chromatography coupled with a UV-VIS detector. The mixture we analyzed was composed of benzyladenine, kinetin, trans-zeatin, cis-zeatin, dihydrozeatin, meta-topolin, ortho-topolin, alpha-naphthalene acetic acid, indole-3-acetic acid, trans-zeatin-7-glucoside, trans-zeatin-O-glucoside, trans-zeatin-9-riboside, meta-topolin-9-riboside and ortho-topolin-9-riboside. We measured the calibration dependences and estimated limits of detection and quantification under the optimal chromatographic conditions (column: Polaris C(18); mobile phase: gradient starting at 2:98 (methanol:0.001% TFA) and was increasing to 55:45 during twenty minutes, and then decreasing for 10 min to 35:65, flow rate: 200 microL x min(-1), temperature: 50 degrees C, wavelength: 210 nm). The detection limits for the target molecules were estimated as tens of ng per mL. We also studied the effect of flax extracts on the phytohormones' signals. Recovery of aliphatic and aromatic cytokinins, metabolites of cytokinins and auxins were within the range from 87 to 105 %. The experimental conditions were tested on a mass selective detector. In addition we analysed a commercial product used for stimulation of roots formation in cuttings of poorly rooting plants. The determined content of alpha-naphthalene acetic acid was in good agreement with that declared by the manufacturer.