In vitro antioksidativno djelovanje nekih Teucrium vrsta (Lamiaceae)

The chemical composition and antioxidant activity of different extracts (diethyl ether, ethyl acetate and n-butanol) obtained from Teucrium species (T. chamaedrys, T. montanum, T. polium) were investigated in this work. Phytochemical screening of the plant extracts proved the presence of flavonoids: luteolin, apigenin and/or diosmetin. The chemical composition of extracts was evaluated by HPLC and spectrophotometry. Antioxidant activities of the extracts were evaluated using three complementary in vitro assays: inhibition of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, inhibition of hydroxyl radicals and protection of beta-carotene-linoleic acid model system. In the first two assays, strong inhibitory activity was shown by T. montanum and T. chamaedrys extracts. In the beta-carotene-linoleic acid model system, extracts from T. polium showed remarkable activity. These findings demonstrated that Teucrium species possess free radical and hydroxyl radical scavenging activity as well as antioxidant activity in vitro.U radu je opisan kemijski sastav i antioksidativno djelovanje različitih ekstrakata (dietil-eter, etil-acetat, n-butanol) iz Teucrium vrsta (T. chamaedrys, T. montanum, T. polium). Fitokemijska istraživanja ekstrakata HPLC metodom i spketrofotometrijom pokazala su prisutnost flavonoida luteolina, apigenina i/ili diosmetina. Antioksidativni učinci ekstrakata praćeni su in vitro pomoću tri komplementarne metode koje se temelje na inhibiciji DPPH (1,1-difenil-2-pikrilhidrazil) radikala, inhibiciji hidroksil radikala ili na zaštiti sustava -karoten-linoleinska kiselina. U prva dva modela dokazan je snažni inhibitorni učinak ekstrakata vrsta T. montanum, T. chamaedrys, dok su u trećem modelu ekstrakti iz T. polium pokazala značajni učinak. Rezulati ukazuju da Teucrium vrste imaju sposobnost vezanja slobodnih i hidroksil radikala i antioksidativni učinak in vitro

Phenolic Compounds Composition of Hypericum perforatum L. Wild-Growing Plants from the Republic of Macedonia

The aim of this study was to provide comprehensive understanding of phenolic compounds composition in roots (RO), non-flower shoots (NFS) and flower shoots (FS) of Hypericum perforatum wild-growing plants from the Republic of Macedonia. Identification of phenolic compounds in plant methanolic extracts was performed by HPLC-DAD/ESI-MS analysis. Chlorogenic acid and 3-p-coumaroylquinic acid were identified in NFS and FS, while 3-feruloylquinic acid was detected in RO and FS extracts. From the group of flavan- 3-ols, (epi)catechin and procyanidins were found in all tested samples, whereas catechin and B-type procyanidin dimer were confirmed in NFS and FS. Four flavonol glycosides (hyperoside, rutin, quercitrin and kaempferol 3-O-rutinoside) were identified in aerial parts. Guaijaverin and kaempferol 3-O-glucoside were exclusively found in NFS. Quercetin, amentoflavone and I3-II8 biapigenin as flavonoid aglycones were detected only in FS extracts. The NFS and FS extracts showed a capability for the accumulation of cyanidin 3-O-glycoside and cyanidin 3-O-rhamnoside, as well for hyperforin and adhyperforin. Naphthodianthrones were represented with pseudohypericin, hypericin and  protopseudohypericin  in  FS, while only hypericin was detected in NFS. Six xanthones, γ-mangostin, 5-O-methyl-2- deprenylrheediaxanthone B, garcinone C, 3,6-dihydroxy-1,5,7-trimethoxy-xanthone, cadensin G and cadensin C were exclusively confirmed in RO extracts. Padiaxanthone was detected in NFS, while dimethylmangiferin in FS extracts. The major finding of this study is the identification of novel xanthones in H. perforatum roots that could be potentially used as bioactive compounds in food and pharmaceutical industry

Multi-element analysis of Macedonian wines by inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma–optical emission spectrometry (IP–OES) for regional classification

Major, minor, and trace elements in wines from the Republic of Macedonia were determined in this study. Both inductively coupled plasma–mass spectrometry (ICP-MS) and inductively coupled plasma– optical emission spectrometry (ICP-OES) were used for accurate determination of the concentration of 42 elements (Ag, Al, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Ho, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, Pr, S, Sm, Tb, Ti, Tl, Tm, U, V, Yb, Zn, Zr) in 25 Macedonian white, rose, and red wines from different wine regions. By means of factor and cluster analyses, the wines were discriminated according to wine type (white vs. red) and geographical origin. The main discriminant elements were B, Ba, Ca, Fe, Mg, Mn, P, and S

In vitro antioksidativno djelovanje nekih Teucrium vrsta (Lamiaceae)

The chemical composition and antioxidant activity of different extracts (diethyl ether, ethyl acetate and n-butanol) obtained from Teucrium species (T. chamaedrys, T. montanum, T. polium) were investigated in this work. Phytochemical screening of the plant extracts proved the presence of flavonoids: luteolin, apigenin and/or diosmetin. The chemical composition of extracts was evaluated by HPLC and spectrophotometry. Antioxidant activities of the extracts were evaluated using three complementary in vitro assays: inhibition of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, inhibition of hydroxyl radicals and protection of beta-carotene-linoleic acid model system. In the first two assays, strong inhibitory activity was shown by T. montanum and T. chamaedrys extracts. In the beta-carotene-linoleic acid model system, extracts from T. polium showed remarkable activity. These findings demonstrated that Teucrium species possess free radical and hydroxyl radical scavenging activity as well as antioxidant activity in vitro.U radu je opisan kemijski sastav i antioksidativno djelovanje različitih ekstrakata (dietil-eter, etil-acetat, n-butanol) iz Teucrium vrsta (T. chamaedrys, T. montanum, T. polium). Fitokemijska istraživanja ekstrakata HPLC metodom i spketrofotometrijom pokazala su prisutnost flavonoida luteolina, apigenina i/ili diosmetina. Antioksidativni učinci ekstrakata praćeni su in vitro pomoću tri komplementarne metode koje se temelje na inhibiciji DPPH (1,1-difenil-2-pikrilhidrazil) radikala, inhibiciji hidroksil radikala ili na zaštiti sustava -karoten-linoleinska kiselina. U prva dva modela dokazan je snažni inhibitorni učinak ekstrakata vrsta T. montanum, T. chamaedrys, dok su u trećem modelu ekstrakti iz T. polium pokazala značajni učinak. Rezulati ukazuju da Teucrium vrste imaju sposobnost vezanja slobodnih i hidroksil radikala i antioksidativni učinak in vitro

QUANTIFICATION OF CAROTENOIDS IN SOME VARIETIES OF RED PEPPERS (CAPSICUM ANNUM L.) AND THEIR PROCESSED PRODUCTS

The red pepper (Capsicum annuum L.) is one of the most essential vegetable crops due to multiple ways it can be processed, as well as for the content of the nutritional phytochemicals, such as carotenoids, which are important for human health. Carotenoids are responsible for the pepper’s colour, as natural antioxidants. They are present in relatively high amounts in the ripe fruit and they play a positive role to ensure the colour stability of the final product.This research examined the carotenoids composition of the red pepper varieties: kurtovska kapija, palanechko chudo and horgosh. For each of the varieties, the following preservation technologies have been applied: pasteurization, freezing, and drying. The extraction method of carotenoids was performed by using methanol-dichloroethan and anhydrous Na2SO4. The changes in the carotenoid pigments of examined varieties during processing have been investigated quantitatively by usage of HPLC technique. The HPLC method was performed on stationary phase Nucleosil 100-3 C18, 250 x 4,6 mm, with a flow rate: 0,7 mL/min, and the gradient program with following eluents: methanol, distilled water and a mixture of isopropanol, acetonitrile and methanol. Carotenoids have been detected between 200 and 700 nm. In all of the analyzed samples, 47 peaks of carotenoids were detected, of which 5 were unknown, one was mixed, and 41 carotenoids were identified. The red pepper variety horgosh was found to contain the highest content of total carotenoids in fresh pepper fruits (690,15 µg/g), frozen pepper (587,88 µg/g), pasteurized pepper (575,76 µg/g) and dried pepper (493,94 µg/g)

Calcium Binding and Transport by Coenzyme Q

Coenzyme Q10 (CoQ10) is one of the essential components of the mitochondrial electron-transport chain (ETC) with the primary function to transfer electrons along and protons across the inner mitochondrial membrane (IMM). The concomitant proton gradient across the IMM is essential for the process of oxidative phosphorylation and consequently ATP production. Cytochrome P450 (CYP450) monoxygenase enzymes are known to induce structural changes in a variety of compounds and are expressed in the IMM. However, it is unknown if CYP450 interacts with CoQ10 and how such an interaction would affect mitochondrial function. Using voltammetry, UV�vis spectrometry, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), fluorescence microscopy and high performance liquid chromatography�mass spectrometry (HPLC�MS), we show that both CoQ10 and its analogue CoQ1, when exposed to CYP450 or alkaline media, undergo structural changes through a complex reaction pathway and form quinone structures with distinct properties. Hereby, one or both methoxy groups at positions 2 and 3 on the quinone ring are replaced by hydroxyl groups in a time-dependent manner. In comparison with the native forms, the electrochemically reduced forms of the new hydroxylated CoQs have higher antioxidative potential and are also now able to bind and transport Ca2þ across artificial biomimetic membranes. Our results open new perspectives on the physiological importance of CoQ10 and its analogues, not only as electron and proton transporters, but also as potential regulators of mitochondrial Ca2þ and redox homeostasis

Multivariate analysis discrimination of various cold-pressed lemon oils from different geographical regions.

The main objective of present study was to investigate the influence of geographical region on the flavour compounds of various cold-pressed lemon oils, i.e. Argentinean, Ivory Cost, Italian, Spanish and Uruguayan. Among the flavor compounds, the major volatile flavour compounds from different chemical classes namely monoterpene hydrocarbons (i.e. limonene, sabinene plus β-pinene, γ-terpinene, myrcene, α-pinene and α-terpinolene), esters (i.e. neryl acetate and geranyl acetate), alcohol (i.e. α-terpineol) and aldehyde compounds (i.e. geranial and neral) were composed of > 90% of total volatile flavor compounds of target cold pressed lemon oils. Uruguayan essential oil had the least concentration level of all major classes of flavor compounds except for alcohol compounds; while the highest content of all chemical classes of flavor compounds identified in this study. The principle component analysis (PCA) allowed us to discriminate various cold-pressed lemon oil based on their origin resource, thereby classify their sensorial attributes

Phenolic Profile of Dark-Grown and Photoperiod-Exposed Hypericum perforatum

Hypericum perforatum L. is a medicinal plant considered as an important natural source of secondary metabolites with a wide range of pharmacological attributes. Hairy roots (HR) were induced from root segments of in vitro grown seedlings from H. perforatum after cocultivation with Agrobacterium rhizogenes A4. Investigations have been made to study the production of phenolic compounds in dark-grown (HR1) and photoperiod-exposed (HR2) cultures. The chromatographic analysis of phenolic acids, flavonols, flavan-3-ols, and xanthones revealed marked differences between HR1 and HR2 cultures. The production of quinic acid, kaempferol, and seven identified xanthones was increased in HR2. Moreover, HR2 showed a capability for de novo biosynthesis of two phenolic acids (3-p-coumaroylquinic acid and 3-feruloylquinic acid), three flavonol glycosides (kaempferol hexoside, hyperoside, and quercetin acetylglycoside), and five xanthones (tetrahydroxy-one-methoxyxanthone, 1,3,5-trihydroxy-6-methoxyxanthone, 1,3,5,6-tetrahydroxy-2-prenylxanthone, paxanthone, and banaxanthone E). On the other side, HR1 cultures were better producers of flavan-3-ols (catechin, epicatechin, and proanthocyanidin dimers) than HR2. This is the first comparative study on phenolic profile of H. perforatum HR cultures grown under dark and photoperiod conditions

Određivanje aglikona flavonoida iz vrsta roda Sideritis (Lamiaceae) iz Makedonije pomoću HPLC UV DAD

Flavonoids obtained from Sideritis species (Lamiaceae), S. raeseri and S. scardica, grown in Macedonia were studied. Qualitative and quantitative analyses of the flavonoid aglycones were performed using high-performance liquid chromatography (HPLC) with a UV diode array detector. Extracts were prepared by acid hydrolysis in acetone, reextraction in ethyl acetate and evaporation to dryness; the residue dissolved in methanol was subjected to HPLC analysis. Isoscutellarein, chryseriol and apigenin were identified in the extracts. Also, a 4’-methyl ether derivative of isoscutellarein was found, together with hypolaetin and its methyl ether derivative, which were identified according to previously isolated glycosides and literature data. Quantitation was performed using calibration with apigenin. According to this screening analysis, the samples of the genus Sideritis from Macedonia are rich in polyhydroxy flavones and analogous with the previously studied Mediterranean Sideritis species from the Ibero-North African and Greek Sideritis species with respect to the presence of 8-OH flavones and their derivatives.U radu su proučavani flavonoidi dobiveni iz Sideritis vrsta (Lamiaceae), S. raeseri i S. scardica, porijeklom iz Makedonije. Kvalitativna i kvantitativna analiza aglikona flavonoida provedena je pomoću tekućinske kromatografije visoke učinkovitosti (HPLC) s UV detektorom. Ekstrakti su pripravljeni kiselom hidrolizom u acetonu, te ponovnom ekstrakcijom etil-acetatom. Ostatak nakon uparavanja je otopljen u metanolu i analiziran pomoću HPLC. Usporedbom s ranije izoliranim glikozidima i s literaturnim podacima u ekstraktima su identifirani izoskutelarein, krizeriol, apigenin, 4\u27-metil eterski derivat izoskutelareina, hipolaetin te njegov metil eter. Kvantifikacija je provedena pomoću kalibracijske krivulje za apigenin. Rezultati ukazuju da su uzorci Sideritis roda iz Makedonije bogati polihidroksiflavonima kao i ranije proučavane mediteranske Sideritis vrste iz sjeverne Afrike i Grčke Sideri

Hydroxylated derivatives of dimethoxy-1,4-benzoquinone as redox switchable earth-alkaline metal ligands and radical scavengers

Benzoquinones (BQ) have important functions in many biological processes. In alkaline environments, BQs can be hydroxylated at quinoid ring proton positions. Very little is known about the chemical reaction leading to these structural transformations as well as about the properties of the obtained hydroxyl benzoquinones. We analyzed the behavior of the naturally occurring 2,6-dimethoxy-1,4-benzoquinone under alkaline conditions and show that upon substitution of methoxy-groups, poly-hydroxyl-derivatives (OHBQ) are formed. The emerging compounds with one or several hydroxyl-substituents on single or fused quinone-rings exist in oxidized or reduced states and are very stable under physiological conditions. In comparison with the parent BQs, OHBQs are stronger radical scavengers and redox switchable earth-alkaline metal ligands. Considering that hydroxylated quinones appear as biosynthetic intermediates or as products of enzymatic reactions, and that BQs present in food or administered as drugs can be hydroxylated by enzymatic pathways, highlights their potential importance in biological systems