Anthocyanins in cowpea [Vigna unguiculata (L.) Walp. ssp. unguiculata]

The aim of this study was to isolate and identify the anthocyanins in the black seed coated cowpea [Vigna unguiculata (L.) Walp. ssp. unguiculata] using reverse phase C-18 open column chromatography and high performance liquid chromatography (HPLC) with diode array detection and electro spray ionization/mass spectrometry (DAD-ESI/MS) analysis, respectively. Anthocyanins were extracted from the coat of black cowpea with 1% trifluoroacetic acid (TFA) in methanol, isolated by RP-C-18 column chromatography, and their structures elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. The isolated anthocyanins were characterized as delphinidin-3-O-glucoside (2) and cyanidin-3-O-glucoside (4). Furthermore, 5 minor anthocyanins were detected and identified as delphinidin-3-O-galactoside (1), cyanidin-3-O-galactoside (3), petunidin-3-O-glucoside (5), peonidin-3-O-glucoside (7), and malvidin-3-O-glucoside (8) based on the fragmentation patterns of HPLC-DADESI/MS analysis.     

Characterisation of phenolic phytochemicals and quality changes related to the harvest times from the leaves of Korean purple perilla (Perilla frutescens)

The objective of this study was to investigate the profiles of phenolic phytochemicals in the leaves of Korean purple perilla (cv. Bora, Perilla fructescens) using reversed-phase C₁₈ column chromatography and HPLC with DAD-ESI/MS analysis. Changes in their contents were also the first reported through eight different harvest times during two months. They were characterised as five anthocyanins and three phenolic acids including cyanidin-3,5-di-O-glucoside (1), cyanidin-3-O-glucoside (2), cyanidin-3-O-(6-O-caffeoyl)glucoside-5-O-glucoside (3), cyanidin-3-O-(6-O-coumaroyl)glucoside-5-O-glucoside (4), cyanidin-3-O-(6-O-coumaroyl)glucoside (5), caffeic acid (6), rosmarinic acid (7), and rosmarinic acid methylester (8). Significant differences were observed between individual and total phytochemical contents, especially, cyanidin-3-O-(6-O-coumaroyl)glucoside-5-O-glucoside (4) and rosmarinic acid (7) exhibited the predominant constituents. Among different harvest times, the highest content was found with 82.473 mg/g on 21st September, while the lowest was 39.000 mg/g on 17th August. These results may be useful in determining the optimal harvest time at which phenolic phytochemicals reaches a maximum level in mid-September.     

Influence of Dekkera bruxellensis on the contents of anthocyanins,organic acids and volatile phenols of Dão red wine

The anthocyanin, organic acid and volatile phenol compositions of red wine obtained from Touriga Nacional grapes growing in the Dão region (Portugal) were determined by HPLC/DAD, HPLC/UV and GC/FID, respectively. By these means, nine anthocyanic compounds (malvidin-3,5-O-diglucoside, cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, peonidin-3-O-glucoside, malvidin-3-O-glucoside, delphinidin, cyanidin, pelargonidin and malvidin), six organic acids (ketoglutaric, tartaric, malic, quinic, lactic and shikimic acids) and two volatile phenols (4-ethylguaiacol and 4-ethylphenol) were identified and quantified. Malvidin-3-O-glucoside, the pair lactic plus shikimic acids and 4-ethylguaiacol were the main anthocyanin, organic acids and volatile phenol, respectively. The effects of nine different Dekkera bruxellensis strains on these chemical parameters were also evaluated. The results obtained indicate that some strains of D. bruxellensis yeast are able to cause deterioration of red wine from the Dão region during its maturation by the production of volatile phenols, namely 4-ethylphenol.     

Identification and quantification of adulteration in Garcinia cambogia commercial products by chromatographic and spectrometric methods

Species of genus Garcinia are rich sources of bioactive constituents with antimicrobial, anticancer, anti-inflammatory, hepatoprotective and anti-HIV activities. Commercial products of Garcinia cambogia are used as anti-obesity drugs with increasing market demand. Because of the high price of its products, it can be adulterated with similar lower-priced species. This study was designed to develop and validate an accurate and efficient method for the detection of any adulteration (G. indica) in G. cambogia products. For this purpose, high performance liquid chromatography (HPLC) was used to analyse the ethanolic fruit rind extracts of G. cambogia and G. indica, their formulations of 0.5, 1, 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 95% G. indica with G. cambogia, and 11 G. cambogia commercial products. The analytical methods were validated by quality assurance parameters of linearity, sensitivity, precision and accuracy. Two marker peaks were detected in G. indica fruit extract, whereas G. cambogia did not show these peaks. The detected peaks were identified as anthocyanins; cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside. In the study to determine the effect of pH and temperature on the stability of its anthocyanin content, HPLC analysis of G. indica extract showed the highest content at pH 1 and 50°C. Using two different mobile phases, the limits of detection (LOD) for cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside were 0.036 and 0.059, and 0.022 and 0.033 mg kg^–1, respectively. Furthermore, the inter-day precision (< 3.2%) confirmed that the applied analytical method fulfils the required criteria of Association of Official Analytical Chemists (AOAC). From this study, it was found that the HPLC method used for the detection of adulteration in G. cambogia products is rapid and accurate.     

Identification and quantification of anthocyanins from the grains of black rice (Oryza sativa L.) varieties

The purpose of this research was conducted to determine anthocyanin content from the grains of 10 Korean black rice varieties. Moreover, the primary constituents including protein and oil were evaluated. Anthocyanins, cyanidin-3-O-glucoside (1) and peonidin-3-O-glucoside (2), were isolated and elucidated using reversephase C₁₈ chromatography, nuclear magnetic resonance (NMR) spectroscopy, and high performance liquid chromatography (HPLC) with diode array detection and electrospray ionization/mass spectrometry (DAD-ESI/MS). Anthocyanin showed significant differences and cyanidin-3-O-glucoside (1) (52.1±6.3-1,601.0±8.5 μg/g) exhibited a markedly higher content than peonidin-3-O-glucoside (2) (ND-82.6±1.2 μg/g). Among varieties, ‘Heugjinjubyeo’ showed the highest anthocyanin (1: 1,601.0±8.5, 2: 82.6±1.2 μg/g), whereas ‘Heughyang’ was the lowest (1: 52.1±6.3 μg/g, 2: ND). Protein and oil exhibited the minor differences and their contents ranged from 10.7±0.0 to 14.1±0.1% and from 2.1±0.0 to 2.9±0.0%. Overall results suggest that anthocyanin can be a key factor in functional property of black rice and ‘Heugjinjubyeo’ may be very important source concerning nutritional value.     

Characterisation of anthocyanins in the black soybean (Glycine max L.) by HPLC-DAD-ESI/MS analysis

The aim of this study was to isolate and identify the anthocyanins in the black seed coated soybean (cv. Cheongja 3, Glycine max (L.) Merr.) using reverse phase C-18 open column chromatography and high-performance liquid chromatography (HPLC) with diode array detection and electro spray ionization/mass spectrometry (DAD-ESI/MS) analysis, respectively. Anthocyanins were extracted from the coat of black soybeans with 1% TFA in methanol, isolated by RP-C-18 column chromatography, and their structures elucidated by 1D and 2D NMR spectroscopy. The isolated anthocyanins were characterised as delphinidin-3-O-glucoside (3), cyanidin-3-O-glucoside (5), petunidin-3-O-glucoside (6), pelargonidin-3-O-glucoside (7) and cyanidin (9). Furthermore, four minor anthocyanins were detected and identified as catechin-cyanidin-3-O-glucoside (1), delphinidin-3-O-galactoside (2), cyanidin-3-O-galactoside (4), and peonidin-3-O-glucoside (8) based on the fragmentation patterns of HPLC-DAD-ESI/MS analysis.     

First accurate profiling of antioxidant anthocyanins and flavonols of Tibouchina urvilleana and Tibouchina mollis edible flowers aided by fractionation with Amberlite XAD-7

A purification and fractionation process of the edible flowers of Tibouchina mollis and Tibouchina urvilleana followed by the first attempt to the anthocyanin and flavonol characterisation and identification by UHPLC-DAD-ESI-MS were developed. T. urvilleana exhibited a higher monomeric anthocyanin content, mainly due to the presence of the 3-O-(6′-p-coumaroyl)-glucoside derivatives of malvidin and petunidin. Quercetin-3-O-hexoside was the major flavonol identified in T. urvilleana, and the lack of myricetin derivatives was also exhibited. The anthocyanin and flavonol profile of T. mollis was more miscellaneous, characterised by the occurrence of cyanidin-3-O-glucoside followed by the 3-O-(6′-p-coumaroyl)-glucoside and 3-O-glucoside derivatives of malvidin and petunidin as anthocyanins, and myricetin, quercetin, and 3-O-hexosides of kaemperol and quercetin as flavonol compounds. Therefore, the anthocyanin and flavonol profile, through a process based on purification and fractionation, could be a useful tool to ensure the authenticity of the Tibouchina. Furthermore, the purification process made the antioxidant activity increase, which is greatly correlated to the reduction capacity.     

Identification of phenolic compounds isolated from pigmented rices and their aldose reductase inhibitory activities

Two anthocyanins (cyanidin-3-O-β-glucoside and peonidin-3-O-β-glucoside) and other phenolic (ferulic acid) were, respectively isolated from black and pigmented brown rices (Oryza sativa L. japonica) and their complete structures were determined by spectroscopic analyses (H NMR, C NMR and MALDI MASS). The HPLC profile of anthocyanins extracted from black rice showed cyanidin-3-O-β-glucoside as the first peak (85%) and peonidin 3-O-β-d-glucoside as the second (15%), while that of pigmented brown rice showed ferulic acid as the first peak (85.7%) and tocols as the second (14.3%). Several tocols were isolated and identified from the unsaponifiable fractions of both rices having some difference on their structures and amounts. The aldose reductase inhibitory activity of isolated compounds was in the following decreasing order: cyanidin-3-glucoside > quercetin > ferulic acid > peonidin-3-glucoside > tocopherol.     

Analysis of Phenolic Compounds of Dabai (Canarium odontophyllum Miq.) Fruits by High-Performance Liquid Chromatography

Dabai (Canarium odontophyllum Miq.) fruit is a popular seasonal indigenous fruit of Sarawak, Malaysia that is always appreciated as an exotic fruit by the local community. The present study was designed to identify and quantify the phenolic compounds of dabai fruits from different divisions of Sarawak. Difference between the purple and red varieties of the fruits was also investigated. Analysis of phenolic compounds was performed by reversed phase high-performance liquid chromatography coupled with diode array detector. Three detection wavelengths (280, 254 and 329 nm) were used to monitor all phenolic compounds (except for anthocyanidins) since they display absorbance maxima at different wavelengths. Characteristic spectra of eluted peaks provide useful information in confirming the identities of peaks. Hydrolysis of phenolic compounds of dabai fruits was insufficient under the milder conditions (30 °C, 2 h) employed thus resulted in unidentified peaks. Two phenolic acids (ellagic and vanillic acids), five flavonoids (catechin, epicatechin, epicatechin gallate, epigallocatechin gallate, apigenin) and ethyl gallate were detected in the fruits. Furthermore, three anthocyanidins (cyanidin, pelargonidin and delphinidin) and four anthocyanins (malvidin-3,5-di-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and peonidin-3-O-glucoside) were detected. All these phenolic compounds were reported in dabai fruits for the first time. The fruit variety affected the anthocyanidins and anthocyanins profile (p < 0.01) but had little or no effect on the phenolic acids and flavonoids profile of the fruits. Within the same variety, diversity in environmental conditions had an impact on the quantitative differences of phenolic compounds (p < 0.05).     

Chemical characterisation of anthocyanins in tamarillo (Solanum betaceum Cav.) and Andes berry (Rubus glaucus Benth.) fruits

The anthocyanin composition of tamarillo (Solanum betaceum Cav., red variety) and Andes berry (Rubus glaucus Benth.) was determined by HPLC–PDA and HPLC–ESIMS. From the anthocyanin-rich extracts (AREs), pure compounds (1–7) were obtained by MLCCC (multilayer countercurrent chromatography) and further preparative HPLC, and their unequivocal structures were obtained by 1D and 2D NMR analyses. The new anthocyanin delphinidin 3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside-3′-O-β-d-glucopyranoside, as well as the known cyanidin-3-O-rutinoside, pelargonidin-3-O-rutinoside, and delphinidin-3-O-rutinoside were identified as constituents of tamarillo fruit. Although the anthocyanin composition of Andes berry had been reported before in the literature, the unequivocal structure elucidation of the major compound, cyanidin-3-O-α-l-rhamnopyranosyl-(1 → 6)-O-β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranoside, was achieved for the first time.     

Flavonoids, sugars and fruit acids of alpine bearberry (Arctostaphylos alpina) from Finnish Lapland

Alpine bearberry (Arctostaphylos alpina L.) is a special circumpolar edible berry primarily used for household purposes but with greater potential in commercial applications than utilized thus far. In this study, the flavonoids of alpine bearberry were investigated with HPLC-DAD and HPLC-MS, and the sugars and fruit acids as trimethylsilyl derivates with GC-FID. The most abundant anthocyanin was cyanidin-3-O-galactoside accounting for over 95% of the anthocyanins. Eight other anthocyanins existed in trace amounts only, the richest of them being cyanidin-3-O-arabinoside and cyanidin-3-O-glucoside. Cyanidin accounted for over 99% of the anthocyanin aglycones. All the flavonols identified were glycosides of quercetin. Majority of the sugars were glucose and fructose while the most abundant fruit acid was quinic acid. The unique anthocyanin composition of alpine bearberry encourages advanced use of the berry as a food ingredient in private households and in industrial applications. In addition, it serves as a unique reference material for research purposes.     

In vitro evaluation of red and green lettuce (Lactuca sativa) for functional food properties

Lettuce (Lactuca sativa) is an important leafy vegetable consumed fresh or in salad mixes. We have compared the functional food properties of selected commercial red and green lettuce varieties grown under field conditions. Both lettuce cultivars were extracted with water at biological (38 °C) and room temperatures (22 °C) at pH 2. The residues from each extraction were further extracted, sequentially with methanol and ethyl acetate. The extracts were evaluated for their in vitro lipid peroxidation (LPO) and cyclooxygenase enzyme (COX) inhibitory activities. Amongst the extracts tested, all three extracts of red lettuce showed higher LPO and COX-1 and -2 enzyme inhibitory activities than did the green lettuce extracts. Red lettuce contained a single anthocyanin, cyanidin-3-O-(6″-malonyl-β-glucopyranoside) (1), which immediately converted to cyanidin-3-O-(6″-malonyl-β-glucopyranoside methyl ester) (2) and cyanidin-3-O-β-glucopyranoside (3) under laboratory conditions. Anthocyanins 1 and 2 inhibited LPO by 88% and 91.5%, respectively, at 0.25 μM concentration. Also, they inhibited COX-2 enzyme by 78.9% and 84.3% and COX-1 by 64% and 65.8%, respectively, at 5 μM. The chicoric acid (4), amongst other phenolics, such as quercetin glucoside, ferulic and caffeic acids, isolated from both green and red lettuce, showed 85.6%, 45.6% and 94% of LPO, COX-1 and -2 enzyme inhibitions at 50 μM, respectively. This is the first report of the LPO, COX-1 and -2 enzyme inhibitory activities of compounds 1, 2 and 4. The variation of phenolics in the red and green lettuces, and specifically the lack of anthocyanins in green lettuce, might account for the higher biological activity obtained with the red variety in our study.     

Identification and characterisation of anthocyanins in the antioxidant activity-containing fraction of Liriope platyphylla fruits

The objective of this study was to investigate antioxidant activities and anthocyanin profiles in the fruits of Liriope platyphylla, where these are considered functional substances in Korea. The acidic methanol extract of this species exhibited potent antioxidant activities, showing 83.9% DPPH scavenging activity and 92.5% ABTS scavenging activity at a concentration of 0.5 mg/ml. Moreover, anthocyanins were identified by reversed-phase C₁₈ column chromatography, NMR spectroscopy, and HPLC-DAD-ESI/MS analysis. Seven anthocyanins were characterised, including delphinidin-3-O-glucoside (1), delphinidin-3-O-rutinoside (2), cyanidin-3-O-glucoside (3), petunidin-3-O-glucoside (4), petunidin-3-O-rutinoside (5), malvidin-3-O-glucoside (6), and malvidin-3-O-rutinoside (7). Among these, petunidin-3-O-rutinoside (5) (7302.2 μg/g) and malvidin-3-O-rutinoside (7) (5776.1 μg/g) were the predominant anthocyanins, whereas the least prevalent anthocyanin was found to be cyanidin-3-O-glucoside (3) (64.9 μg/g). Therefore, our results suggest that strong antioxidant activities of the acidic methanol extract of L. platyphylla fruits are correlated with high anthocyanin contents, particularly the petunidin-3-O-rutinoside (5) and malvidin-3-O-rutinoside (7).     

Effect of cyclodextrins on the thermodynamic and kinetic properties of cyanidin-3-O-glucoside

In this study, the effect of α and β-cyclodextrin on cyanidin-3-O-glucoside color was investigated by UV–visible absorption techniques. The equilibrium and kinetic constants of the network of chemical reactions taking place in cyanidin-3-O-glucoside were also studied in water at 25 °C by UV–visible absorption techniques. The results showed that the addition of β-cyclodextrin resulted in the fading of anthocyanin solution, and this fading effect was greater at higher pH. This anti-copigmentation effect is caused by the selective inclusion and stabilization of the anthocyanin colorless forms into the β-cyclodextrin cavity. Oppositely, no changes were observed in the cyanidin-3-O-glucoside absorption spectra with the addition of α-cyclodextrin.Direct pH jump, from thermally equilibrated solutions at pH = 1.0 (flavylium cation, AH⁺), shows three kinetic processes: formation of the base A, hydration reaction to form the hemiketal B and the chalcone cis–trans isomerization (Cc–Ct). The results obtained clearly indicated that the equilibrium and kinetic constants of the network of chemical reactions taking place in cyanidin-3-O-glucoside were affected by the presence of β-cyclodextrin. Molecular inclusion in the β-cyclodextrin cavity resulted in the increase of the isomerization observed rate constant (k_obs) at pH 5.3 and in the increase of the hydration equilibrium constant K_h which is in agreement with the fading of the anthocyanin solution. For the macrocycle α-cyclodextrin, no significant changes were observed on the equilibrium and kinetic constants, which suggests that the inclusion of cyanidin-3-glucoside in the α-cyclodextrin's cavity is not favored.     

Positive effects of glycosylated anthocyanin isolated from an edible berry fruit (Acanthopanax sessiliflorum) on its antioxidant activity and color stability

A major chromatographic peak of anthocyanin from ogaja (Acanthopanax sessiliflorum) fruit represented 95.4% of total absorbable compounds at 518 nm. The mass-to-charge ratio (m/z) of this colorant was determined to be 581 by LC-MS, which was identical to the molecular mass of cyanidin-3-O-sambubioside. After acid hydrolysis of the purified anthocyanin fraction, it was structurally confirmed by thin layer chromatography (TLC) and high-performance anion exchange chromatography (HPAEC) analyses. As a result, the sugar moieties linked to cyanidin were glucose and xylose. The purified cyanidin-3-O-sambubioside and cyanidin had greater antioxidant activities than l-ascorbic acid by both DPPH and ABTS methods. Cyanidin-3-O-sambubioside was more stable than cyanidin in the response to heat (80 °C), and both fluorescent and UV light. l-Ascorbic acid had an adverse effect on the color stability of anthocyanin. In this study, we demonstrated that glycosylation on anthocyanidin would provide an effective protection barrier for its color stability against the exposure to various food processing conditions.     

An approach for extraction,purification, characterization and quantitation of acylated-anthocyanins from <Emphasis Type="Italic">Nitraria tangutorun</Emphasis> Bobr. fruit

In the present study, a systematic approach for extraction, purification and analysis of acylated-anthocyanins from Nitraria tangutorun Bobr. fruit was explored. Six acylated-anthocyanins in N. tangutorun fruit were identified by HPLC-MS/MS, and a rapid and efficient HPLC-DAD method was developed to analyze the acylated-anthocyanins. Ultrasonic-assisted extraction conditions of acylated-anthocyanins were optimized using response surface methodology, extraction at 70 °C for 32 min using 70% methanol solution (0.1% HCl, v/v) rendered an extract with 80.37?±?2.66 mg/100 g of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and 97.88?±?4.06 mg/100 g of total acylated-anthocyanins. Nine macroporous resins were investigated for preliminary purification of acylated-anthocyanins. According to the static/dynamic adsorption and desorption tests, XDA-6 macroporous resin exhibited the maximum potential for preparing acylated-anthocyanins. The purity of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside (43.30 mg/g) in purified acylated-anthocyanins was 201.89 times of that of the extract (0.21 mg/g), and the purity of total acylated-anthocyanins increased from 0.36 to 56.44 mg/g. Besides, the stability (t _1/2) of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and total acylated-anthocyanins increased by more than five-fold after purification using XDA-6. The established methods of analysis, extraction and purification of acylated-anthocyanins were hopefully utilized in food industry.     

Soluble phenolics and antioxidant properties of soybean (Glycine max L.) cultivars with varying seed coat colours

This research was the first to investigate nutritional components, including soluble phenolics (isoflavones and anthocyanins), protein, oil, and fatty acid as well as antioxidant activities in different coloured seed coat soybeans (yellow, black, brown, and green) for two crop years. The soluble phenolics differed significantly with cultivars, crop years, and seed coat colours, while protein, oil, and fatty acid exhibited only slight variations. Especially, malonylgenistin and cyanidin-3-O-glucoside compositions had the most remarkable variations. Green soybeans had the highest average isoflavone content (3079.42 μg/g), followed by yellow (2393.41 μg/g), and black soybeans (2373.97 μg/g), with brown soybeans showing the lowest value (1821.82 μg/g). Anthocyanins showed only in black soybeans, with the average contents of the primary anthocyanins, cyanidin-3-O-glucoside, delphinidine-3-O-glucoside, and petunidin-3-O-glucoside, quantified at 11.046, 1.971, and 0.557 mg/g, respectively. Additionally, Nogchae of green soybean and Geomjeongkong 2 of black soybean may be recommended as potential cultivars owing to the highest average isoflavone (4411.10 μg/g) and anthocyanin (21.537 mg/g) contents. The scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also differed remarkably, depending upon isoflavone and anthocyanin contents, with black soybeans exhibiting the highest antioxidant effects.     

Chemical composition and antioxidant activity of tronchuda cabbage internal leaves

A phytochemical study was undertaken on the internal leaves of tronchuda cabbage (Brassica oleracea L. var. costata DC). Seventeen phenolic compounds were characterized and quantified by reversed-phase HPLC-DAD-ESI-MS ⁿ and HPLC/DAD, respectively: quercetin 3-O-sophoroside-7-O-glucoside, 3-p-coumaroylquinic acid, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(caffeoyl)-sophoroside-7-O-glucoside, sinapoyl gluc-oside acid, kaempferol 3-O-(sinapoyl)-sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl)-sophoroside-7-O-glucoside, kaempferol 3-O-(p-coumaroyl)-sophoroside-7-O-glucoside, 4-p-coumaroylquinic acid, sinapic acid, kaempferol 3-O-sophoroside, 3 isomeric forms of 1,2-disinapoylgentiobiose, 1-sinapoyl-2-feruloylgentiobiose, 1,2,2-trisinapoylgentiobiose and 1,2′-disinapoyl-2-ferul-oylgentiobiose. Seven organic acids (aconitic, citric, ascorbic, malic, quinic, shikimic and fumaric acids) were also identified and quantified. The hot water extract of tronchuda cabbage internal leaves was investigated for its capacity to act as a scavenger of DPPH^• radical and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid), exhibiting antioxidant capacity in a concentration dependent manner against all radicals.     

Changes of anthocyanins and hydroxycinnamic acids affecting the skin colour during maturation of sweet cherries (Prunus avium L.)

The content and relative amounts of anthocyanins and hydroxycinnamic acids (HCA) were determined in local sweet cherries (cultivar Petrovka) at 7 stages of maturity, by means of high performance liquid chromatography (HPLC), and compared to instrumentally assessed skin colour of the same sweet cherries. Skin colour of harvested samples was measured using the CIE L^*,a^*,b^* system. The contents of neochlorogenic and 3′-p-coumarylquinnic acids decreased with no significant change in ratio during ripening, except for the first 4 days of maturation, when the ratio changed due to increased content of neochlorogenic acid. The linear increase of total anthocyanins during maturation was observed without the trend of stabilization in the final stages of maturity. The colour change of Petrovka during maturation was influenced by the increase of total anthocyanins, consisting mostly of cyanidin-3-rutinoside and cyanidin-3-glucoside (97-98% of the total). The chroma and L^* values appeared to be optimal indicators of anthocyanin accumulation during maturation, and better than the a^* value and hue angle. The accumulation of anthocyanins from 507.1 to 1150.9 mg of cyanidin-3-rutinoside/kg of fresh weight (FW) during the second half of maturation caused the formation of a new colour cast of Petrovka, which influenced the decrease of redness and colour intensity, as recognized by CIE L^*,a^*,b^* colour space.     

Phenolic Compounds from the Leaves of Vitis labrusca and Vitis vinifera L. as a Source of Waste Byproducts: Development and Validation of LC Method and Antichemotactic Activity

The cultivation of Vitis (Vitaceae) grape varieties is one of the most important economic activities in agribusiness in southern Brazil. Vitis varieties are rich in polyphenolic compounds with several pharmacological and biological activities, such as antioxidant action. In this context, this study analyzed qualitatively and quantitatively the anthocyans and flavonoids found in the leaves of grape varieties Vitis vinifera and Vitis labrusca. For this purpose, vine leaf extracts were prepared and the chemical profile of each was characterized by LC/MS-MS. Two high performance liquid chromatography-validated methods were performed using UV/VIS-LC-DAD detector to quantify phenolic compounds. The main anthocyanins isolated from vine leaves were cyanidin-3-O-glucoside and peonidin-3-O-glucoside. The flavonoids identified were rutin, quercetin-3-O-galactoside, quercetin-3-O-glucoside, and quercetin-3-O-glucuronide, which was the predominant compound. The Waters X-Terra® RP18 column allowed the effective separation of quercetin-3-O-glucuronide from the other flavonoids for the first time, besides the partial separation of quercetin-3-O-galactoside from quercetin-3-O-glucoside. Furthermore, another phenolic compound was confirmed by MS spectrometry, using direct infusion, as being trans-caftaric acid. The present study also investigates the antichemotactic activity in vitro of grape crude extracts, fractions, and isolated compounds. It was demonstrated that almost all fractions and isolated compounds showed increased antichemotactic effect in response to LPS with a more pronounced values of IC₅₀ for anthocyanins fraction, rutin, quercetin-3-O-galactoside, and trans-caftaric acid (0.9, 1.6, 3.7, and 5.1 ng/mL, respectively).