Proximate Composition,Antioxidant Properties,and Hepatoprotective Activity of Three Species of Shellfish of the Pacific Coast of Russia

The objective of the present study was to investigate the proximate composition, antiradical properties and hepatoprotective activity of three species of shellfish, Corbicula japonica, Spisula sachalinensis, and Anadara broughtonii, from the coastal areas of Far East Russia. Biologically active peptides such as taurine (3.74 g/100 g protein) and ornithine (2.12 g/100 g protein) have been found in the tissues of A. broughtonii. C. japonica contains a high amount of ornithine (5.57 g/100 g protein) and taurine (0.85 g/100 g protein). The maximum DPPH and ABTS radical scavenging activity (36.0 µg ascorbic acid/g protein and 0.68 µmol/Trolox equiv/g protein, respectively) was determined for the tissue of C. japonica. The protein and peptide molecular weight distribution of the shellfish tissue water extracts was investigated using HPLC. It was found that the amount of low molecular weight proteins and peptides were significantly and positively correlated with radical scavenging activity (Pearson’s correlation coefficient = 0.96), while the amount of high molecular weight proteins negatively correlated with radical scavenging activity (Pearson’s correlation coefficient = −0.86). Hepatoprotective activity, measured by the survival rate of HepG2 hepatocytes after cotreatment with t-BHP, was detected for C. japonica. The highest protection (95.3 ± 2.4%) was achieved by the cold water extract of C. japonica at the concentration of 200 mg/mL. Moreover, oral administration of hot water extract of C. japonica to rats before the treatment with CCl₄ exhibited a markedly protective effect by lowering serum levels of ALT and AST, inhibiting the changes in biochemical parameters of functional state of rat liver, including MDA, SOD, GSH and GST.     

Composition and Antimicrobial Activity of the Essential Oils of Two Endemic Species from Turkey: <Emphasis Type="Italic">Sideritis cilicica</Emphasis> and <Emphasis Type="Italic">Sideritis bilgerana</Emphasis>

Aerial parts of Sideritis cilicica Boiss. & Bal. and Sideritis bilgerana P.H. Davis (Lamiaceae) were hydrodistilled to obtain essential oils that were then analyzed by GC and GC/MS. β-Pinene (39%), α-pinene (28%), and β-phellandrene (20%) were the main components in the oil of S. cilicica, while β-pinene (48%), and α-pinene (32%) were the major constituents in the oil of S. bilgerana. The antimicrobial activities of the oils were evaluated by using the microdilution broth method. Both of the oils showed good inhibitory effects on C. albicans. __________ Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 559–561, November–December, 2005.     

Essential Oils of Sideritis Species of Turkey Belonging to the Section Empedoclia

The paper summarizes the work done on the essential oil content and composition of fifty Sideritis species of Turkey belonging to the section Empedoclia. The water-distilled oils were analyzed by GC/MS. The oils were characterized as having mono- and sesquiterpenoids.     

A Concise Review of Current In Vitro Chemical and Cell-Based Antioxidant Assay Methods

Antioxidants remain interesting molecules of choice for suppression of the toxic effects of free radicals in foods and human systems. The current practice involves the use of mainly synthetic molecules as potent antioxidant agents. However, due to the potential negative impact on human health, there is an intensive effort within the research community to develop natural alternatives with similar antioxidant efficacy but without the negative side effects of synthetic molecules. Still, the successful development of new molecules depends on the use of reliable chemical or cell culture assays to screen antioxidant properties. Chemical antioxidant assays include the determination of scavenging ability against free radicals such as DPPH, superoxide anion radicals, hydroxyl radicals, hydrogen peroxide, and nitric oxide. Other antioxidant tests include the ability of compounds to bind and sequester prooxidant metal cations, reduce ferric iron, and attenuate the rate of lipid oxidation. Ex vivo tests utilize cell cultures to confirm entry of the molecules into cells and the ability to quench synthetic intracellular free radicals or to stimulate the increased biosynthesis of endogenous antioxidants. In order to assist researchers in their choice of antioxidant evaluation methods, this review presents background scientific information on some of the most commonly used antioxidant assays with a comparative discussion of the relevance of published literature data to food science and human nutrition applications.     

Synthesis and Antioxidant Properties of Novel Silybin Analogues

Eight novel silybin analogues (7a-h) were synthesized and their antioxidant properties including the capability of scavenging superoxide anion free radicals and the inhibitory effect on DPPH free radicals were determined. Several synthetic compounds showed comparable antioxidative effect to that of quercetin.     

Phenolic Profiles,Antioxidant and Anti-Inflammatory Activities of Hydrodistillation Wastewaters from Five Lamiaceae Species

Distillation is the most widely used method to obtain an essential oil from plant material. The biomass used in the process is returned as a solid residue together with variable amounts of water rich in water-soluble compounds, which currently are not addressed to any further application. The scope of this work was to evaluate the phytochemical composition of wastewaters coming from hydrodistillation (DWWs) of five aromatic plants belonging to the Lamiaceae family, and to assess their in vitro antioxidant and anti-inflammatory activities. The phenolic profiles of the DWWs were determined by HPLC-DAD and HPLC-ESI/MS. Free radical scavenging ability, oxygen radical antioxidant capacity and superoxide dismutase mimetic activity of the samples under study were measured. Moreover, to investigate the anti-inflammatory activity of the DWWs, an in vitro experimental model of intestinal inflammation was used. The DWW samples’ phytochemical analysis allowed the identification of 37 phenolic compounds, all exhibiting good antioxidant and anti-inflammatory activity. Our study contributes to the knowledge on the polyphenolic composition of the DWWs of five aromatic plants of the Lamiaceae family. The results highlight the presence of compounds with proven biological activity, and therefore of great interest in the pharmaceutical and nutraceutical fields.     

Determination of the Free Radical Scavenging Activity of Lycium Extracts

Lycium species growing in Turkey have not so far been studied sufficiently. For this reason, non-polar and polar extracts obtained from the fruits of Lycium barbarum L. and L. Ruthenicum Murray (Solanaceae) were assessed both in vitro for their potential as free radical scavenger crude extracts and their phenolic composition. Fruits of Lycium species were sequentially extracted with petroleum ether, ethyl acetate, methanol, n-butanol, and water in a Soxhlet extractor. All the extracts were assessed for the scavenging of the nitrogen-centered free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH^.) by in vitro method. Furthermore, the composition of each extract was investigated both in terms of its Folin-Ciocalteau reactive components and its qualitative content. The phenolic compounds within the extracts were determined as benzoic acid and hydroxycinnamic acid derivatives, flavonoids, and anthocyanins according to their retention time and UV spectral data by HPLC-DAD system.     

Pharmacological Potential and Chemical Composition of Crocus sativus Leaf Extracts

Crocus sativus L. (saffron) has been traditionally used as a food coloring or flavoring agent, but recent research has shown its potent pharmacological activity to tackle several health-related conditions. Crocus sp. leaves, and petals are the by-products of saffron production and are not usually used in the medicine or food industries. The present study was designed to determine the chemical composition of the water and ethanolic extracts of C. sativus leaves and test their cytotoxic activity against melanoma (IGR39) and triple-negative breast cancer (MDA-MB-231) cell lines by MTT assay. We also determined their anti-allergic, anti-inflammatory, and anti-viral activities. HPLC fingerprint analysis showed the presence of 16 compounds, including hydroxycinnamic acids, xanthones, flavonoids, and isoflavonoids, which could contribute to the extracts’ biological activities. For the first time, compounds such as tectoridin, iristectorigenin B, nigricin, and irigenin were identified in Crocus leaf extracts. The results showed that mangiferin (up to 2 mg/g dry weight) and isoorientin (8.5 mg/g dry weight) were the major active ingredients in the leaf extracts. The ethanolic extract reduced the viability of IGR39 and MDA-MB-231 cancer cells with EC₅₀ = 410 ± 100 and 330 ± 40 µg/mL, respectively. It was more active than the aqueous extract. Kaempferol and quercetin were identified as the most active compounds. Our results showed that Crocus leaves contain secondary metabolites with potent cytotoxic and antioxidant activities.     

In Vitro Bioaccessibility and Antioxidant Activity of Phenolic Compounds in Coffee-Fortified Yogurt

Yogurt is considered one of the most popular and healthy dairy products, and has been exploited as a delivery matrix for phenolic compounds. In this study, coffee powder was added to yogurt as a functional ingredient to produce coffee-fortified yogurt. Total phenolic compounds, antioxidant activity and individual hydroxycinnamic acids have been identified and quantified through mass spectrometry. The results from coffee-fortified yogurt were compared with fermented coffee and plain yogurt. Coffee-fortified yogurt had higher total phenolic content and antioxidant activity compared to plain yogurt. However, the total phenolic compounds found in coffee-fortified yogurt represented only 38.9% of the original content in coffee. Caffeoylquinic acids were the most abundant phenolic compounds in coffee. Fermented coffee and coffee-fortified yogurt displayed lower amounts of individual phenolic compounds with respect to coffee (69.8% and 52.4% of recovery, respectively). A protective effect of the yogurt matrix on total and individual coffee phenolic compounds has been observed after in vitro digestion, resulting in a higher bioaccessibility in comparison with digested fermented coffee. Moreover, coffee-fortified yogurt showed the highest antioxidant values after digestion. These findings clearly demonstrate that coffee-fortified yogurt can be considered a significant source of bioaccessible hydroxycinnamic acids, besides its health benefits as a fermented dairy product.     

Synthesis and Antioxidant Activity of New Catechol Thioethers with the Methylene Linker

Novel catechol thio-ethers with different heterocyclic substituents at sulfur atom were prepared by reacting 3,5-di-tert-butyl-6-methoxymethylcatechol with functionalized thiols under acidic conditions. A common feature of compounds is a methylene bridge between the catechol ring and thioether group. Two catechols with the thio-ether group, bound directly to the catechol ring, were also considered to assess the effect of the methylene linker on the antioxidant properties. The crystal structures of thio-ethers with benzo-thiazole moieties were established by single-crystal X-ray analysis. The radical scavenging and antioxidant activities were determined using 2,2′-diphenyl-1-picrylhydrazyl radical test, ABTS^∙+, CUPRAC (TEAC) assays, the reaction with superoxide radical anion generated by xanthine oxidase (NBT assay), the oxidative damage of the DNA, and the process of lipid peroxidation of rat liver (Wistar) homogenates in vitro. Most catechol-thioethers exhibit the antioxidant effect, which varies from mild to moderate depending on the model system. The dual anti/prooxidant activity characterizes compounds with adamantyl or thio-phenol substituent at the sulfur atom. Catechol thio-ethers containing heterocyclic groups (thiazole, thiazoline, benzo-thiazole, benzo-xazole) can be considered effective antioxidants with cytoprotective properties. These compounds can protect molecules of DNA and lipids from the different radical species.     

Isobornylchalcones as Scaffold for the Synthesis of Diarylpyrazolines with Antioxidant Activity

The pyrazoline ring is defined as a “privileged structure” in medicinal chemistry. A variety of pharmacological properties of pyrazolines is associated with the nature and position of various substituents, which is especially evident in diarylpyrazolines. Compounds with a chalcone fragment show a wide range of biological properties as well as high reactivity which is primarily due to the presence of an α, β-unsaturated carbonyl system. At the same time, bicyclic monoterpenoids deserve special attention as a source of a key structural block or as one of the pharmacophore components of biologically active molecules. A series of new diarylpyrazoline derivatives based on isobornylchalcones with different substitutes (MeO, Hal, NO₂, N(Me)₂) was synthesized. Antioxidant properties of the obtained compounds were comparatively evaluated using in vitro model Fe²⁺/ascorbate-initiated lipid peroxidation in the substrate containing brain lipids of laboratory mice. It was demonstrated that the combination of the electron-donating group in the para-position of ring B and OH-group in the ring A in the structure of chalcone fragment provides significant antioxidant activity of synthesized diarylpyrazoline derivatives.     

Phytochemical Composition,Antibacterial, Antioxidant and Antidiabetic Potentials of Cydonia oblonga Bark

Cydonia oblonga is a medicinal plant that is used to treat a number of health complications in traditional medication systems. The objective of this study was to evaluate the phytochemical composition, and antibacterial, antioxidant, and ant-diabetic potentials of methanolic extracts of Cydonia oblonga bark. The Cydonia oblonga bark extraction was fractionated through HPLC and seven purified fractions labeled as F1, F2, F3, F4, F5, F6, and F7 were obtained. The HPLC-UV analysis of methanolic extract showed the presence of a number of possible compounds. The GC-MS and HPLC analysis confirmed the presence of the following bioactive compounds in the crude extract and purified fractions: malic acid, mandelic acid, quercetin, caffeic acid, catechin hydrate, as morin (HPLC analysis), BIS-(2-ethylhexyl)phthalate and diisooctyl phthalate (F1), carbamide (F2, used as fertilizer), octasiloxane and dimethylsiloxanecyclictrimer (F3), silicic acid and cyclotrisiloxane (F4), 6-AH-cAMP, 4H-cyclopropa[5′,6′]benz[1′,2′,7,8]azule, and 4-(4-chlorophenyl)-3-morpholinepyrol-2-yl)-butenedioic acid (F5), isopropyamine (F6), and 1-propylhydrazine (F7). The extract and purified fractions were then tested for biological activities. All the purified fractions and methanolic extract showed effective antibacterial activity; however, the highest activity was recorded for methanolic extract against Staphylococcus aureus and Streptococcus pneumonia. Antioxidant evaluation of methanolic extract and purified fractions against DPPH showed strong % inhibition of the synthetic free radical. The methanolic extract exhibited 87.41 ± 0.54% inhibition whereas fractions showed: F1, 85.45 ± 0.85; F2, 65.78 ± 0.68; F3, 58.61 ± 0.58; F4, 80.76 ± 0.59; F5, 571.29 ± 0.49; F6, 85.28 ± 0.94; and F7, 48.45 ± 0.62% inhibition. Ascorbic acid (standard) was used as a control with 94.88 ± 0.56% inhibition at a maximum concentration of 1000 µg/mL. The α-glucosidase inhibition assay of methanolic extract and purified fractions at a maximum concentration of 1000 µg/mL showed activities as: methanolic extract, 78.21 ± 0.67; F1, 55.01 ± 0.29; F2, 56.10 ± 0.24; F3, 62.44 ± 1.03; F4, 70.52 ± 0.15; F5, 62.18 ± 0.92; F6, 72.68 ± 0.2; and F7, 57.33 ± 0.05% inhibition. α-Amylase % inhibition of methanolic extract and purified fractions were noted as: methanolic extract, 77.98 ± 0.57; F1, 79.72 ± 0.02; F2, 79.72 ± 0.02; F3, 82.16 ± 0.48; F4, 77.37 ± 0.28; F5, 72.14 ± 0.30; F6, 74.24 ± 0.29; and F7, 56.58 ± 0.10 at the highest concentration of 1000 µg/mL. Acarbose (standard) showed 87.65 ± 0.71% inhibition of α-glucosidase and 85.99 ± 0.44% inhibition of α-amylase at the highest concentration of 1000 µg/mL. It was found that all biological activities of methanolic extract and purified fractions might be attributed to the fact that they are rich sources of phenolic and flavonoids along with other bioactive compounds. The total phenolic and flavonoid contents of methanolic extract were recorded higher as compared to purified fractions (TPC = 70% and TFC = 69%). Amongst the purified fractions, fraction 6 exhibited the highest TPC value (64%), and purified fraction 1 exhibited the highest value of TFC (58%). Recent research demonstrated that Cydonia oblonga may be considered an antibacterial medicinal plant. The result of the present study revealed that it might be utilized for the isolation of bioactive phytochemicals that can lead to new opportunities in the discovery of new antibiotics.     

Phenolic compounds from the aqueous extract of Acacia catechu

From the aqueous extract of Acacia catechu,two new phenolic compounds(3R,4R)-3-(3,4-dihydroxyphenyl)-4-hydroxycy-clohexanone (1) and(4R)-5-(1-(3,4-dihydrophenyl)-3-oxobutyl)-dihydrofuran-2(3H)-one(2) were obtained.Their structures were determined on the basis of spectroscopic analysis.Free-radical scavenging activities of them were evaluated.     

Honey and Pollen Phenolic Composition,Antioxidant Capacity,and DNA Protecting Properties

The phenolic composition, antioxidant capacity, and the dsDNA oxidative damage protecting properties, of ten honey and two pollen samples, from different countries, Portugal, Algeria, Romania, and Greece, using differential pulse voltammetry, DPPH^. spectrophotometric assay, reversed‐phase high performance liquid chromatography with electrochemical detection, and agarose gel electrophoresis, were investigated. The honey samples highest antioxidant capacity was from Multi floral from Greece and the lowest for Mono floral black locust from Romania. The pollen from Romania presented higher antioxidant capacity compared with the pollen from Portugal but both pollen samples have a greater antioxidant capacity compared with the honey samples. In the presence of honey and pollen the DNA oxidative damage, induced by hydroxyl radicals generated through the Fenton reaction, was decreased.     

Chemical Composition,Antioxidant and Antimicrobial Activity of Some Types of Honey from Banat Region,Romania

Honey is a natural product with multiple health benefits. The paper presents the chemical characterization and the antioxidant and antimicrobial potential of ten types of honey (knotweed, linden, wild cherry, acacia, honeydew, oilseed rape, sunflower, phacelia, plain polyflora and hill polyflora) from the Banat region, Romania. We studied the water content, dry matter, impurities, acidity and pH of honey. We also determined the content of reducing sugar, minerals and flavonoids and the total phenolic content. All honey samples analysed showed good nutritional characteristics according to the standard codex for honey. From the analysis of the mineral content of the honey samples, we observed a variability in the macro and microminerals, influenced by the botanical origin, ranging between 0.25% (wild cherry honey) and 0.54% (honeydew). The toxic metals’ (Cd and Pb) levels met the standard for almost all samples analysed except for knotweed. The flavonoid content of the samples ranged from 9.29 mg QE/100 g for wild cherry honey to 263.86 mg QE/100 g for linden honey, and for polyphenols between 177.6 mgGAE/100 g for acacia honey and 1159.3 mgGAE/100 g for honeydew. The best antioxidant capacity was registered in the case of linden honey (79.89%) and honeydew (79.20%) and the weakest in acacia (41.88%) and wild cherries (50.4%). All studied honey samples showed antimicrobial activity, depending on the type of honey, concentration and strain analysed. The novelty of this study is given by the complex approach of the study of honey quality, both from the perspective of chemical attributes and the evaluation of the antimicrobial potential on specific strains in correlation with the botanical and geographical origin of the analyzed area.     

Effect of Fish Bone Bioactive Peptides on Oxidative,Inflammatory and Pigmentation Processes Triggered by UVB Irradiation in Skin Cells

In the present study, we evaluated for the first time the photoprotective effect of fish bone bioactive peptides (FBBP) preparation isolated from silver carp (Hypophthalmichthys molitrix) discarded tissue using in vitro experimental models of skin cells exposed to ultraviolet B (UVB) irradiation and stressing agents. FBBP preparation was obtained by papain treatment of minced bones and centrifugal ultrafiltration, and the molecular weight (MW) distribution was characterized by size exclusion and reversed-phase high performance liquid chromatography (RP-HPLC). In vitro assessment of the effect of FBBP pretreatment in UVB-irradiated L929 fibroblasts and HaCaT keratinocytes revealed their cytoprotective activity. Their capacity to efficiently reduce reactive oxygen species (ROS) production and lipid peroxidation varied in a dose-dependent manner, and it was greater in fibroblasts. A decrease of proinflammatory cytokines secretion, in particular of tumor necrosis factor alpha (TNF-α), was found after FBBP pretreatment of THP-1-derived inflamed macrophages. Melanin production and tyrosinase activity investigated in UVB-irradiated Mel-Juso cells were lowered in direct relation to FBBP concentrations. FBBP fractions with high radical scavenging activity were separated by ion exchange chromatography, and two collagenic sequences were identified. All these results offer new scientific data on aquaculture fish bone-derived peptides confirming their ability to control the antioxidant, anti-inflammatory and pigmentation processes developed during UV irradiation of skin cells and recommend their use as valuable natural ingredients of photoprotective cosmeceutical products.     

Effects of Long-Term Storage on Radical Scavenging Properties and Phenolic Content of Kombucha from Black Tea

Kombucha is a fermented beverage. Its consumption has significantly increased during the last decades due to its perceived beneficial effects. For this reason, it has become a highly commercialized drink that is produced industrially. However, kombucha is still also a homemade beverage, and the parameters which, besides its organoleptic characteristics, define the duration of its potential beneficial properties over time, are poorly known. Therefore, this study aimed to determine the effect of 9-month storage at 4 °C with 30-day sampling on the pH, total phenolic, and flavonoid contents, free radical scavenging properties of kombucha fermented from black tea. Our results highlighted that, after four months, the phenolic content decreased significantly from the initial value of 234.1 ± 1.4 µg GAE mL⁻¹ to 202.9 ± 2.1 µg GAE mL⁻¹, as well its antioxidant capacity tested by two in vitro models, DPPH, and ABTS assays. Concomitantly, the pH value increased from 2.82 to 3.16. The novel findings of this pilot study revealed that kombucha from sugared black tea can be stored at refrigerator temperature for four months. After this period the antioxidant properties of kombucha are no longer retained.     

Polyphenolic compounds from Malus hupehensis and their free radical scavenging effects

One new 4-chromanone glycoside, 5-O-β-d-glucopyranoside-4-chromanone (1), together with 21 known polyphenols, was isolated from the leaves of Malus hupehensis. Their structures were elucidated on the basis of extensive spectroscopic methods including NMR (1D and 2D), mass (ESIMS and HRESIMS), IR, and by comparison with the data reported in the literature. Some of the isolated compounds were screened for antioxidant activity. Compounds 18 and 14 exhibited significant antioxidant activities with SC₅₀ values 2.73 and 2.91 μg/mL, respectively, while 17, 19, 11, 7, 20, 22, 12 and 13 exhibited moderate activities with SC₅₀ values ranging from 5.24–11.86 μg/mL. The HPLC fingerprint profiles of the leaves and fruits extracts were also analysed, which showed that the constituents were almost the same in both the extracts except for the content of phlorizin which was present in higher amount in the leaves.     

咪唑并[1,2-a]吡啶化合物的无溶剂合成及其抗氧化性能

无溶剂条件下,2-氨基吡啶、芳香醛和异氰基乙酸乙酯发生Groebke-Blackburn-Bienaymé三组分反应,高效合成了6个咪唑并[1,2-a]吡啶化合物,产率89%~97%,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI）确证。并通过抑制HO·和还原型谷胱甘肽自由基(GS·)引发的DNA氧化反应体系,对化合物的抗氧化活性进行了检测。结果表明：在抑制HO·引发的DNA氧化反应体系中,6个化合物相对空白硫代巴比妥酸活性物质吸光度百分数（TBARS百分数）可达32.2%~72.1%;在抑制GS·引发的DNA氧化反应体系中,6个化合物的TBARS百分数可达34.8%~81.3%。     

Antioxidant flavonol glycosides from Dorycnium hirsutum

Seven flavonol glycosides were isolated and identified from the aerial parts of Dorycnium hirsutum, together with catechin, D-pinitol, β-sitosterol, and stearic acid. The extracts and the isolated flavonol glycosides were evaluated for their antioxidant activity, using the DPPH test (radical scavenging) and the lipoxygenase assay (lipid peroxidation). Dedicated to the memory of Prof. I. Morelli. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 233–235, May–June, 2006.