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

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

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

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

Mikroinkapsuliranje bakterije Lactobacillus casei u izolatu sojinog proteina i alginata pomoću sušenja raspršivanjem

This article presents a novel formulation for preparation of Lactobacillus casei 01 encapsulated in soy protein isolate and alginate microparticles using spray drying method. A response surface methodology was used to optimise the formulation and the central composite face-centered design was applied to study the effects of critical material attributes and process parameters on viability of the probiotic after microencapsulation and in simulated gastrointestinal conditions. Spherical microparticles were produced in high yield (64 %), narrow size distribution (d50=9.7 µm, span=0.47) and favourable mucoadhesive properties, with viability of the probiotic of 11.67, 10.05, 9.47 and 9.20 log CFU/g after microencapsulation, 3 h in simulated gastric and intestinal conditions and four-month cold storage, respectively. Fourier-transform infrared spectroscopy confirmed the probiotic stability after microencapsulation, while differential scanning calorimetry and thermogravimetry pointed to high thermal stability of the soy protein isolate-alginate microparticles with encapsulated probiotic. These favourable properties of the probiotic microparticles make them suitable for incorporation into functional food or pharmaceutical products.U radu je prikazan novi način pripreme mikrokapsula bakterije Lactobacillus casei 01 u izolatu sojinog proteina i alginata pomoću sušenja raspršivanjem. Metodologijom odzivnih površina optimiran je sastav mikrokapsula, a korištenjem plošno centriranog plana ispitan je utjecaj glavnih sastojaka kapsula te parametara procesa na preživljavanje mikroinkapsuliranog probiotika u simuliranim uvjetima gastrointestinalnog trakta. Najviše je proizvedeno kuglastih mikročestica (64 %), s raspodjelom veličina od d50=9,7 μm (raspon od 0,47) i povoljnim mukoadhezivnim svojstvima. Nakon mikroenkapsulacije preživjelo je 11,67 log CFU/g probiotika, nakon 3 sata u simuliranom želučanom soku 10,50 log CFU/g, u simuliranom soku tankog crijeva 9,47 log CFU/g, a nakon četiri mjeseca hladnog skladištenja 9,20 log CFU/g. Stabilnost probiotika nakon mikroinkapsulacije potvrđena je infracrvenom spektroskopijom s Fourierovom transformacijom, a toplinska stabilnost mikrokapsula probiotika u izolatu proteina soje i alginatu diferencijalnom pretražnom kalorimetrijom i termogravimetrijom. Zaključeno je da se zbog njihovih povoljnih svojstava mikrokapsule probiotika mogu upotrijebiti u proizvodnji funkcionalne hrane i farmaceutskih proizvoda

HPLC-DAD-ESI/MS monitoring of stilbenes content in Vranec red wines produced with traditional and modern fermentation methods

Quantification of stilbenes was performed on Vranac wines (vintage 2008 and 2009) produced by traditional and modern fermentation methods, applying different enological additions (enzyme, oak chips and grape tannins). Stilbenes, trans-resveratrol and trans-resveratrol-3-glucoside were determined using the HPLC/DAD/ESI-MS and MS/MS technique. Trans-resveratrol ranged from 0.09 to 3.3 mg/L and the trans-resveratrol-3-glucoside was present in a range of 1.13 to 2.6 mg/L. The influence of vintage, fermentation tanks and enological additions was noticed on the content of stilbenes. Wines from vintage 2008 presented higher amount of stilbenes (on average: 1.89 mg/L) compared to the wines from 2009 (on average: 1.59 mg/L) probably because of the difference in the temperature and humidity in both years. Application of modern fermentation tanks (Sifa and Ganimede) followed by additions of enzyme, oak chips and grape tannins resulted in a higher amount of stilbenes. PCA presented grouping of wines according to the applied fermentation method

Development of a spectrophotometric method for assessment of the relative reactivity of monocarbonyl analogs of curcumin with 2-(dimethylamino)ethanethiol

In order to improve the bioavailability of curcumin, studies have been undertaken to prepare the so-called monocarbonyl analogs of curcumin (MACs) and assess their biological activity. These analogs contain an electrophilic α,β-unsaturated carbonyl moiety (Michael acceptor). Several key biological processes are connected/controlled with thiol alkylation (glutathione, cysteine, cysteine peptide residues). The most likely reaction is the Michael addition between the α,β-unsaturated acceptor and a corresponding thiol. 2,6-Bisarylidenecyclohexanone and 3,5-bisarylidenepiperidin-4-one scaffolds offer convenient tunability of electrophilicity and redox properties of the Michael acceptor by the introduction of various substituents. In this study, several MACs were prepared by Claisen-Schmidt condensation reaction, and their reactivity with 2-(dimethylamino)ethanethiol was evaluated. For this purpose, based on the UV-Vis spectra of the analogs and thiol(s), a proper method for spectrophotometric evaluation of their reactivity with 2-(dimethylamino)ethanethiol was optimized. The relative reactivity of the analogs was 7 > 2 > 5 > 4 > 1 ≈ 6. The developed method is simple, and it can be extended to assess the reactivity of other MACs

Assay of Urinary Excretion of Polyphenols after Ingestion of a Cup of Mountain Tea (Sideritis scardica) Measured by HPLC-DAD-ESI-MS/MS

Flavonoids and phenolic acid metabolites excreted in human urine after ingestion of Sideritis scardica decoction with characterized polyphenolic composition were studied. A feeding study was carried out with 10 human volunteers, and urine samples were collected for 24 h after ingestion of the <i>Sidertis</i> decoction. Polyphenol metabolites were identified and quantified in urine samples by HPLC with tandem mass spectrometric detection. Thirty-one different metabolites of hypolaetin, methylhypolaetin, isoscutellarein, methylisoscutellarein, and apigenin and 32 phenolic acid metabolites were detected and quantified using a method validated for this purpose. The urinary excretion of polyphenol metabolites corresponded to 5% (n/n) of the intake of polyphenols from the <i>Sideritis</i> decoction. Flavonoid metabolites were dominant in urine samples with 87–94% of total polyphenolic metabolites content. The most abundant metabolites were methylhypolaetin and methylisoscutellarein glucuronides. Urinary excretion of isoscutellarein (35.61%) was 10 times higher than that of hypolaetin (3.67%). Apigenin also showed high urinary excretion (32.46%)

Swelling properties of Lactobacillus casei loaded whey protein-Ca-alginate microparticles

New approach for microencapsulation of the probiotic Lactobacillus casei was employed in order to improve the viability of the probiotic and achieve targeted delivery in the lower intestine after oral administration. The objective of this work was to determine the swelling behaviour of the optimal formulation of microparticles in mediums with different pH values respective to simulated gastrointestinal conditions