•Before us nobody performed the elemental analysis of quince seeds.•Six hydroxycinnamic acids were found in the extracts of quince peel and pulp.•The most abundant hydroxycinnamic acid in quince peel ...and pulp is 5-CQA.•Six flavonols were determined in the extracts of quince.•Statistics show strong negative correlation between flavonoids and toxic metals.
Six hydroxycinnamic acids were identified and determined quantitatively in methanol and acetone extracts from quince peel and pulp, namely 3-O-caffeoylquinic acid (3-CQA), 4-p-coumaroylquinic acid (HC1), 4-O-caffeoylquinic acid (4-CQA), 5-O-caffeoylquinic acid (5-CQA), derivative of p-coumaroylquinic acid (HC2) and 3,5-dicaffeoylquinic acid (3,5-diCQA). The most abundant hydroxycinnamic acid was 5-CQA (neochlorogenic acid) with 259.12–481.4mg/kgf.w. in peel and 97.33–217.36mg/kg in quince pulp. Six flavonols were determined in the extracts from quince, quercetin-3-galactoside (Q-Ga), quercetin-3-rutinoside (Q-Ru), quercetin-3-glucoside (Q-Glu), kaempferol-3-rutinoside (K-Ru), kaempferol-3-glucoside (K-Glu) and derivative of quercetin produced in the reaction between quercetin-glucoside and p-coumaric acid (Q-Glu-p-CouA). Elemental analysis of quince seeds has not been performed previously. Also, using principal component and cluster analyses, we determined a strong negative relationship between total phenols and flavonoids, and Ni and Pb, specifically higher concentrations of these compounds were associated with lower concentrations of these metals.
New twelve in silico designed coumarin-based ERα antagonists, namely 3DQ-1a to 3DQ-1е, were synthesized and confirmed as selective ERα antagonists, showing potencies ranging from single-digit ...nanomolar to picomolar. The hits were confirmed as selective estrogen receptor modulators and validated as antiproliferative agents using MCF-7 breast cancer cell lines exerting from picomolar to low nanomolar potency, at the same time showing no agonistic activity within endometrial cell lines. Their mechanism of action was inspected and revealed to be through the inhibition of the Raf-1/MAPK/ERK signal transduction pathway, preventing hormone-mediated gene expression on either genomic direct or genomic indirect level, and stopping the MCF-7 cells proliferation at G0/G1 phase. In vivo experiments, by means of the per os administration to female Wistar rats with pre-induced breast cancer, distinguished six derivatives, 3DQ-4a, 3DQ-2a, 3DQ-1a, 3DQ-1b, 3DQ-2b, and 3DQ-3b, showing remarkable potency as tumor suppressors endowed with optimal pharmacokinetic profiles and no significant histopathological profiles. The presented data indicate the new compounds as potential candidates to be submitted in clinical trials for breast cancer therapy.
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•Twelve novel coumarin-based ERα antagonists, 3DQ-1a to 3DQ-1е, were synthesized•Compounds exerted picomolar to nanomolar potency against ERα and MCF-7 cell lines•Compounds acted at Raf-1/MAPK/ERK, hERE and AP-1, and MCF-7 G0/G1 phase levels•Compounds suppressed breast cancer in vivo showing optimal pharmacokinetic profiles•3DQ-4a, 3DQ-2a, 3DQ-1a, 3DQ-1b, 3DQ-2b, and 3DQ-3b are clinical trials candidates
Xanthine oxidase (XO) is an important enzyme catalyzing the hydroxylation of hypoxanthine to xanthine and xanthine to uric acid which is excreted by kidneys. Excessive production and/or inadequate ...excretion of uric acid results in hyperuricemia. This paper presents a detailed review of methods of isolation, determination of xanthine oxidase activity, and the effect of plant extracts and their constituents on it. Determining the content and activities of XO can be used for diagnostic purposes. Testing inhibition of XO is important for detection of potentially effective compounds or extracts that can be used to treat diseases that are caused by increased activity of XO. In vitro bioassays are used to examine test material for XO inhibition, as inhibitors of XO may be potentially useful for the treatment of gout or other XO induced diseases. Several authors reported on the XO inhibitory potential of traditionally used medicinal plants.
The results of developed kinetic-spectrophotometric method for serum urea determination by modified colorimetric Berthelot procedure were presented in this paper. To obtain high sensitivity, all ...reaction rates were monitored spectrophotometrically by measuring the change of absorbance with time at 700 nm. A differential variant of the tangent method was used for the processing of the kinetic data based on linear dependence of absorbance on time. The method is valid over the 0.25–2.50 µg cm
−3
urea concentration interval with RSD range 8.33–2.02%. The limit of detection was calculated as 0.09 µg cm
−3
. The interference effects of some metal ions, anions, antibiotics, and other molecules were investigated to access the method selectivity. The method was successfully applied for the determination of urea in human quality control blood serum.
A simple, rapid, sensitive and selective kinetic spectrophotometric method for determination of Fe(III) traces was elaborated in this paper. It is based on the catalytic effect of Fe(III) ions on ...oxidation of potassium salt of disulphonated hydroquinone (K2S2Hy) by hydrogen peroxide in acidic media, at a constant ionic strength. At the working temperature of 20?C and the wavelength of 450.0 nm, optimal conditions for determination of iron were found so that iron (III) can be determined by the proposed method in the concentration range of 1.87 to 18.7 ng cm-3. Corresponding RSD values were determined to be in the range 4.22 to 10.33 %. The limit of detection (LOD) calculated in two ways was found to be 1.07 ng cm-3 i.e. 1.11 ng cm-3 Fe(III). In order to assess the selectivity of the method effects of different ions on the reaction rate were also determined. It was found that presence of oxalates and citrates in the w/w ratio to Fe(III) 1:1 under selected experimental conditions interferes with determination of iron. Then the method was applied for determination of Fe(III) traces in white radish juice. The results agreed well with those obtained by atomic absorption spectrometry.
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Peach (Prunus persica L.) is a fruit of high nutritional and economic value. Carbohydrates, dietary fibers, minerals and organic acids are among the major constituents of peach fruit, which ...contribute to the nutritional quality of both fresh fruits and juice. Polyphenolic compounds found in peach may play an important role in physiological functions related to human health. Different polyphenolics may have varied biological activities including antioxidant activity. In this study antioxidant characteristics between peel and pulp of different peach cultivars ('Radmilovcanka', 'June Gold', 'Blake', 'Hale', 'Vesna', 'Adria') and one of nectarine ('Fantasia') were investigated. The peel and pulp extracts showed a huge amount of total phenolics (TP), total flavonoids (TF), total hydroxycinnamates (TH) and total flavonols (TFL), ranging from 42.7-211.4, 11.1-128.5 mg GAE/100 g fresh weight (f.w.) (TP), 21.9 -94.9, 5.0-58.9 mg CE/100 g f.w. (TF), 28.4-389.2, 8.5-165.8 mg kg-1 f.w. (TH) and 17.3-54 mg kg-1 f.w. (TFL). High contents of phenolic compounds were significantly correlated with high antioxidant capacities. Peach pulp and peel differ significantly in their phenolic profiles: the pulp contains mainly chlorogenic, neochlorogenic and p-coumaric acids, whereas the peel possesses chlorogenic, neochlorogenic and p-coumaric acids together with several flavonol glycosides in huge amounts. Our results indicate that cultivar and extraction solvent play important roles in phenolic compositions and antioxidant properties of peach and nectarine extracts, which was shown using statistical analysis (ANOVA). There are high correlations between extracted phenolic compounds and peach and nectarine cultivars, and used solvent and part of the fruit (peel and pulp).
Blackthorn (Prunus spinosa L.) is commonly used in food industry and
phytotherapy. The contents of phenols, flavonoids, anthocyanins and
antioxidative activity in extracts of blackthorn fruit were ...determined using
spectrophotometric methods. The content of total phenol compounds varies from
15.33 to 20.94 mg GAE g-1 of fresh fruit. The content of total flavonoids is
very low, and ranges from 0.419 to 1.31 mg QE g-1 of fresh fruits.
Anthocyanins content lies between 0.112 mg cyanidin 3-glucoside/g of fresh
sample in ethanol extract and 0.265 mg of cyanidin 3-glucoside g-1 of fresh
blackthorn fruit in methanol-water 50/50 (v/v) extract. The differences in
total phenol compounds content depend on used extraction medium as a
consequence of different polarity of used organic solvents and their
mixtures, which selectively extract individual compounds. All explored
extracts exhibited strong scavenging activity against DPPH radicals, which
ranges from 32.05 to 89.10%. Phenolic acids (neochlorogenic and caffeic
acids), flavonoids (quercetin and myricetin) and anthocyanins
(cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, peonidin-3-O-glucoside)
were identified in investigated ethanol extracts by HPLC analysis. Ethanol
extract shows significant antimicrobial activity against Staphylococcus
aureus ATCC 6538, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC
9027 and Salmonella abony NCTC 6017 and antifungal activity against Candida
albicans ATCC 10231. Blackthorn fruit extract exhibits a high phenolic
content and a high antioxidant activity, and can be used as an antioxidant in
food and pharmaceutical industries.
The absorption and fluorescence emission spectra of cyanidin and cyanidin
3-O-?-glucopyranoside (Cy3Glc) at pH 5.5 in aqueous solution have been
studied. The most effective fluorescence excitations ...of cyanidin were at the
UV absorption maxima at 220 and at 230 nm and at higher wavelengths at 270
and at 280 nm. Cyanidin exhibits fluorescence emission maxima at 310 nm and
in the visible range at 615 nm. For the Cy3Glc most effective fluorescence
excitation was at 220 and at 230 nm and at higher wavelengths at 300 and at
310 nm. Cy3Glc has fluorescence emission spectra with the maximum at 380 nm
and does not show fluorescence emission in the visible range. If compare
fluorescence emission spectra of cyanidin and Cy3Glc it can be seen that
fluorescence emission intensity for cyanidin is significantly higher than
that for Cy3Glc. These results reveals the impact of 3-glucosidic
substitution at C-3 of aglycone (to form Cy3Glc) on the significantly
decrease in fluorescence emission intensity, and disappearance of the
fluorescence emission in visible wavelength range.
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