Selenium and vitamin E concentrations in human milk and formula milk from Hungary

The metabolic roles of vitamin E and selenium are closely related, and to a very great extent, each can compensate for the deficiency of the other. The aim of the study was to determine and compare the Se and vitamin E (α- and γ-tocopherol) contents of breast milk and commercially available infant formulas in Hungary. The Se content was measured by instrumental neutron activation analysis (INAA), while the α-, and γ-tocopherol concentrations were determined by high performance liquid chromatography (HPLC). The mean Se concentration was 17.4±2.8 μg/L in transitional and 13.8±2.3 μg/L in mature milk. It was found that, all of the starter (ST), the follow-on (FO) and the specialized formulas (SF) had lower Se content than breast milk. Transitional breast milk resulted in a higher Se intake (14 μg/day) than mature milk (11 μg/day). The daily Se intakes in Hungarian infants were within the Recommended Dietary Allowance (RDA) range. The natural vitamin E contents of human milk were similar during the early and late lactation. Mature breast milk had 3.30±1.13 mg/L α-TE concentration and this was significantly higher than that of in ST (1.98±1.57), and FO (1.77±0.78), or in SF ready to feed preparations (1.03±0.74). The present study suggests that the formulas for the optimal development of young infants, should contain concentrations of these antioxidants on a level which is comparable to that of the human milk.     

Suitability of ultra-high performance liquid chromatography for the determination of fat-soluble nutritional status (vitamins A, E, D, and individual carotenoids)

Our aim was to assess the suitability of ultra-high performance liquid chromatography (UHPLC) for the simultaneous determination of biomarkers of vitamins A (retinol, retinyl esters), E (α- and γ-tocopherol), D (25-OH-vitamin D), and the major carotenoids in human serum to be used in clinical practice. UHPLC analysis was performed on HSS T3 column (2.1 × 100 mm; 1.8 μm) using gradient elution and UV–VIS detection. The system allows the simultaneous determination of retinol, retinyl palmitate, 25-OH-vitamin D, α- and γ-tocopherol, lutein plus zeaxanthin, α-carotene, β-carotene, α- and β-cryptoxanthin and lycopene. The method showed a good linearity over the physiological range with an adequate accuracy in samples from quality control programs. Suitability of the method in clinical practice was tested by analyzing samples (n = 286) from patients. In conclusion, UHPLC constitutes a reliable approach for nutrient/biomarker profiling allowing the rapid, simultaneous and low-cost determination of vitamins A, E, and D (including vitamers and ester forms) and the major carotenoids in clinical practice.     

β Phase transformations in the Cu–11mass%Al alloy with Ag additions

In the Cu–Al system, due to the sluggishness of the β ↔ (α + γ₁) eutectoid reaction, the β phase can be retained metastably. During quenching, metastable β alloys undergo a martensitic transformation to a β′ phase at Al low content. The ordering reaction β ↔ β₁ precedes the martensitic transformation. The influence of Ag additions on the reactions containing the β phase in the Cu–11mass%Al alloy was studied using differential scanning calorimetry and in situ X-ray diffractometry. The results indicated that, on cooling, two reactions are occurring in the same temperature range, the β → (α + γ₁) decomposition reaction and the β → β₁ reaction, with different reaction mechanisms (diffusive for the former and ordering for the latter) and, consequently, with different reaction rates. For lower cooling rates, the dominant is the decomposition reaction and for higher cooling rates the ordering reaction prevails. On heating, the (α + γ₁) → β reverse eutectoid reaction occurs with a resulting β phase saturated with α. The increase of Ag concentration retards the β → (α + γ₁) decomposition reaction and the β → β₁ ordering reaction, which occurs in the same temperature range, becomes the predominant process.     

Use of NIRS technology with a remote reflectance fibre-optic probe for predicting mineral composition (Ca,K, P,Fe, Mn,Na, Zn), protein and moisture in alfalfa

In the present work we study the use of near-infrared spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe for the analysis of major (Ca, K, P) and minor (Fe, Mn, Na, Zn) elements, protein and moisture in alfalfa. The method allows immediate analysis of the alfalfa without prior sample treatment or destruction through direct application of the fibre-optic probe on ground samples in the case of the mineral composition and on-ground and compacted (baled) samples in the case of protein and humidity. The regression method employed was modified partial least-squares (MPLS). The calibration results obtained using samples of alfalfa allowed the determination of Ca, K, P, Fe, Mn, Na and Zn, with a standard error of prediction (SEP(C)) and a correlation coefficient (RSQ) expressed in mg/kg of alfalfa of 1.37 × 10³ and 0.878 for Ca, 1.10 × 10³ and 0.899 for K, 227 and 0.909 for P, 103 and 0.948 for Fe, 5.1 and 0.843 for Mn, 86.2 and 0.979 for Na, and of 1.9 and 0.853 for Zn, respectively. The SEP(C) and RSQ values (in %) for protein and moisture in ground samples were 0.548 and 0.871 and 0.150 and 0.981, respectively; while in the compacted samples they were 0.564 and 0.826 and 0.262 and 0.935, respectively. The prediction capacity of the model and the robustness of the method were checked in the external validation in alfalfa samples of unknown composition, and the results confirmed the suitability of the method.     

Analysis of vitamin E in food and phytopharmaceutical preparations by HPLC and HPLC-APCI-MS-MS

Summary The analysis of α, β, γ, δ-tocopherols, trienols, α-tocopheryl acetate and nicotinate (vitamin E) in complex matrices was carried out using a new liquid chromatographic (HPLC) method giving better separation efficiency, selectivity and sensitivity than that described in the literature. The use of normal-phase (NP)-HPLC on silica gel with issoctane-diisopropylether-1,4-dioxane as optimized mobilepphase yielded higher resolution than conventional reversed-phase (RP)-HPLC using methanol mobile phase. Identification of peaks was by UV-absorbance at 295 nm, diode array, or fluorescence detection (λ _ex = 295 nm,λ _ex = 330 nm). The latter was found to be more selective and ten times more sensitive than UV-absorbance detection. A quadrupole, ion-trap mass spectrometer with an atmospheric-pressure ionization (APCl) interface was used to detect vitamin E constituents in the femtomole range. With collision-induced dissociation (CID) in the ion source, which gave characteristic fragmentation, the identity of the investigated compounds could be confirmed. Plots of peak area versus amount injected allowed quantitation of α, β, γ, δ-tocopherols and-trienols, α-tocopheryl acetate and nicotinate in real samples such as peanut, almond, spinach, spelt grain bran, latex and tablets. The method described offers fast identification and quantitation of vitamin E constituents of complex biological origin. Dedicated to Professor Dr. Heinz Engelhardt on the occasion of his 65^th birthday.     

Thermodynamic evaluation of antibacterial activity for inclusion complexes of amoxicillin with cyclodextrins

The antibacterial action of amoxicillin (AMPC) and the inclusion complexes of AMPC with α-, β- and γ-cyclodextrins (α-CD, β-CD and γ-CD, respectively) to Escherichia coli B (E. coli) was evaluated by isothermal titration microcalorimetry and by petri-dish bioassay method. The effects of the compounds on produced heat during the exponential phase of the E. coli growing were measured and the growing rate constants of the cells was calculated from the power-time (p-t) curve before and after the treatment with AMPC. Results from the both methods showed that the antibacterial activity became stronger in the following order: AMPC-βCD > AMPC-γCD ≈ AMPC-αCD > AMPC only.     

Determination of Natural Vitamin E from Italian Hazelnut Leaves

A new potential source of natural vitamin E from thirteen samples of Corylus avellana L. leaves was screened: the major Italian cultivar — Tonda romana (collected from Latium and Sardinia localities); ten local genotypes from Sardinia — Moro seme, Suconcale, Moro, Sarda grossa, Sarda grossa seme, Sarda schiacciata, Coccoredda, Sarda lunga, Sarda piccola and Sarda tardiva; wild genotype — Selvatico from Latium. The determination was performed after optimizing the high-efficiency pressurized liquid extraction (PLE) conditions of α-tocopherol from Italian hazelnut tree green leaves. Moro from Sardinia showed the highest content of α-tocopherol (237.4±0.3 μg/g d.w). Leaves of this genotype may be considered as a potential new source for natural α-tocopherol. __________ Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 538–540, November–December, 2005.     

PRODUCTS AND RELATIVE REACTION RATES OF THE OXIDATION OF TOCOPHEROLS WITH SINGLET MOLECULAR OXYGEN

Abstract— The relative reactivity of singlet molecular oxygen, 0₂(¹Δ_g), α-,β-,Γ-and δ with -tocopherol (vitamin E) was investigated using microwave discharge generation as a uniquely clean source of singlet oxygen and using a hydrocarbon solvent to approximate the membrane environment. The relative efficiencies of the tocopherols for O₂(¹Δg) were found to decrease in the order: D-α-tocopherol > D-β-tocopheroI > D–Γ-tocopherol > D-δ-tocopherol. The reaction products in all cases were found to be mixtures of quinone and quinone epoxides apparently resulting from decomposition of the primary product, the hydroperoxydienone.     

Separation of α-tocotrienol oxidation products and eight tocochromanols by HPLC with DAD and fluorescence detection and identification of unknown peaks by DAD,PBI-EIMS,FTIR, and NMR

Tocotrienols, like tocopherols, are members of the vitamin E family. While tocopherols (T) have been studied intensively, only recently have tocotrienols (T3) received increased attention due to their special health benefits. However, these positive attributes of T3 are probably lost as a result of degradation during food storage and processing, and there is little information about their oxidation products. Of particular interest are the oxidation products of α-tocotrienol (α-T3) as this is the least thermostable T3 isomer with the highest rate of degradation. The objective of this study was therefore to develop a reliable method for the determination of the most important oxidation products of α-T3 along with other tocochromanol isomers. We developed a high-performance liquid chromatography method with diode array detection, fluorescence detection, and a particle beam interface electron impact mass spectroscopy in order to separate the most important oxidation products of α-T3 (α-T3 spirodimers/spirotrimers, α-tocotrienoldihydroxy dimer, 7-formyl-β-tocotrienol (7-FβT3), 5-formyl-γ-tocotrienol (5-FγT3), α-tocotrienolquinone (α-T3Q), and α-T3Q dimers and α-tocotrienolquinone epoxides (α-T3QE)) from eight tocochromanol isomers. Furthermore, we sought to identify the as yet unknown oxidation products 5-FγT3, 7-FβT3, α-T3Q-dimer, and α-T3QE. Of these, 5-FγT3 was fully characterized by Fourier transform infrared spectroscopy and ¹H and ¹³C nuclear magnetic resonance spectroscopy.     

Thermodynamic behavior of lipid nanoparticles upon delivery of Vitamin E derivatives into the skin: in vitro studies

This article reports the thermodynamic changes of lipid nanoparticles (LN) upon delivery of lipophilic vitamin E derivatives to the skin. Skin penetration of α-tocopherol (α-T) and α-tocopherol acetate (α-Ta) into and across porcine ear skin was investigated in vitro using tape-stripping test in modified Franz diffusion cells. Wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) have been used to characterize the polymorphism of the solid matrix of LN before and after in vitro skin penetration assay. Cetyl palmitate LN with a loading capacity of 20% of vitamin E derivatives (with regard to the lipid matrix) have shown the typical β’ modification of waxes, with a crystallinity index (%CI) between 30 and 40%. Mean particle size and shelf life stability was assessed by static (laser diffractometry, LD) and dynamic (photon correlation spectroscopy, PCS) light scattering techniques. Submicron-sized LN were produced, i.e., 99% of LN showed a size below 600 nm immediately after production. A mean size between 180 and 350 nm (polydispersity index < 0.25) was obtained for LN stored at both 8 and 22 °C, and this size range was kept constant for at least 20 days of shelf life. Quantification of α-T and α-Ta in the skin using tape-stripping provided a 3.4-fold increase in the level of actives within the stratum corneum (SC) and 1.3-fold increase in the viable epidermis (VE). LN increased skin penetration of both actives, following a cumulative release during 8 h in modified Franz diffusion cells. The differences in the distribution levels observed between α-T and α-Ta when delivered via LN was due to the different thermodynamic activity of both actives, i.e., following increased partition coefficient of α-Ta into SC and VE, in comparison to α-T.     

Detection and quantification of additives (urea, biuret and poultry litter) in alfalfas by NIR spectroscopy with fibre-optic probe

The additives (urea, biuret and poultry litter) present in alfalfa, which contribute non-proteic nitrogen, were analysed using near infrared spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe. We used 75 samples of known alfalfa without additives and 75 samples with each of the additives, urea (0.01-10%), biuret (0.01-10%) and poultry litter (1-25%). Using the discriminant partial least squares (DPLS) algorithm, the presence or absence of the additives urea, biuret and poultry litter is classified and predicted with a high prediction rate of 96.9%, 100% and 100%, obtaining the equations of discrimination for each additive. The regression method employed for the quantification was modified partial least squares (MPLS). The equations were developed using the fibre-optic probe to determine the content of urea, biuret and poultry litter with multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEP (C)) of 0.990, 0.28% for urea, 0.991, 0.29% for biuret and 0.925, 2.08% for poultry litter. The work permits the instantaneous and simultaneous prediction and determination of urea, biuret and poultry litter in alfalfas, applying the fibre-optic directly on the ground samples of alfalfa.     

Synthesis of optically active analogs of α-tocopherol based on (S)-(+)-dihydromyrcene

New optically active analogs of α-tocopherol (vitamin E) were synthesized starting from enantiomerically enriched (ee≈50%) (S)-(+)-dihydromyrcene. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1631–1634, September, 2000.     

Inclusion compounds of cystostatic active (C5H5)2VCl2 and (CH3C5H4)2VCl2 with α-, β- and γ-cyclodextrines: Synthesis, EPR study and microbiological behavior toward Escherichia coli

The inclusion of vanadocene dichloride (VDC) and 1,1′-dimethyl vanadocene dichloride (MeVDC) into cyclodextrines (α-CD, β-CD and γ-CD) was studied by EPR spectroscopy. It was found that VDC and MeVDC with β-CD and γ-CD form true inclusion compounds, but with α-CD, VDC and MeVDC gave only fine dispersion mixtures. The inclusion was validated by anisotropic EPR spectra of solid samples. In addition, the antimicrobial was validated by anisotropic EPR spectra of solid samples. In addition, the antimicrobial behavior (against E. coli) of each of the complexes was determined. It was established that not only did VDC and MeVDC cause elongation of E. coli, but also the new vanadocene inclusion complexes were effective in this regard.     

Comparison of α- and β-trifluoromethylsubstituted acrylic acids in their reactions with thiols

α-(Trifluoromethyl)acrylic acid (1) and γ,γ,γ-trifluorocrotonic acid (2) add AcSH (exothermally and at 100 °C, respectively) in the absence of a catalyst to form products of β-thiolation, which can be easily hydrolyzed to the corresponding β-mercaptoalkanoic acids. Thiols also add regiospecifically to acids1 (in the absence of a catalyst) and2 only in the presence of trifluoromethanesulfonic acid as the catalyst) when heated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1230–1232, June, 1997.     

Comparative Study of the Inclusion Complexation of Pizotifen and Ketotifen with Native and Modified Cyclodextrins

The interaction of two benzocycloheptanes namely, pizotifen (Pizo) and ketotifen (Keto), with cyclodextrins (CDs: α-, β-, γ-, and HP-β-CDs) has been investigated by several techniques including phase solubility, X-ray powder diffractometry, ¹H-nuclear magnetic resonance and molecular mechanical modeling. The effects of CD type, pH, ionic strength and temperature on complex stability were also explored. The complex formation constant (K ₁₁) values for the Pizo/CD system follows the decreasing order β-CD > γ-CD > HP-β-CD > α-CD. However, for the Keto/CD system it follows the decreasing order γ-CD > β-CD > HP-β-CD > α-CD. The tendency of Pizo and Keto to complex with β-CD is driven to the extent of 70% by the hydrophobic effect. Complex formation of Keto and Pizo was substantially driven by entropy (>100 J⋅mol⁻¹⋅K⁻¹) but slightly retarded by enthalpy (3–8 kJ⋅mol⁻¹). ¹H-NMR and MM⁺ studies indicate multimodal inclusion of the methylpiperadine, thiophene and phenyl moieties into the β-CD cavity.     

Elucidation of the Role of the Complex in Hydride Transfer Reaction between Methylene Blue and 1-Benzyl-1,4-dihydronictinamide by Effect of γ-Cyclodextrin

The kinetics of the hydride transfer reaction between Methylene Blue (MB⁺) and 1-benzyl-1,4-dihydronicotinamide (BNAH) were studied in 10% ethanol-90% water mixed solvents containing β- and γ-cyclodextrins (β-CD and γ-CD). The pseudo-first order rate constant shows kinetic saturation at high initial concentration of BNAH. This indicates the formation of a complex between MB⁺ and BNAH. The reaction was suppressed by addition of β-CD, but enhanced by addition of γ-CD. MB⁺ and BNAH were separately accommodated within the β-CD cavity and the cavity walls may protect the activity site of the reactants. On the other hand, in the MB⁺-BNAH-γ-CD system, the inclusion of the complex between MB⁺ and BNAH with γ-CD occurred. This effect of γ-CD can distinguish between the productive and non-productive nature of the complex.     

Electron paramagnetic resonance (EPR) study of γ-radiation-induced radicals in 1,3,5-trithiane and its derivatives

Radicals formed in γ-irradiated 1,3,5-trithiane (TT) and its three derivatives, α- and β-2,4,6-trimethyl-1,3,5-trithiane (α-TMT and β-TMT), and 2,4,6-trimethyl-2,4,6-triphenyl-1,3,5-trithiane (TMTPT), were studied by the electron paramagnetic resonance (EPR) method in the solid state. The sulfur radical cations (>S^+•) were identified in all compounds at 77 K. In TT and its two derivatives, α-TMT and β-TMT, the >S^+• decay via deprotonation-forming C-centered radicals. Further increase of temperature up to 293 K results in the appearance of thiyl-type radicals (RS^•). In TMTPT, the >S^+• are stable up to 250 K. They formed the intermolecularly three-electron-bonded dimeric radical cations (S∴S)⁺ while RS^• radicals were not observed. Some of the radical assignments and their EPR parameters (g and a hyperfine splittings) obtained support from the DFT calculations.     

Determination of inorganic elements in animal feeds by NIRS technology and a fibre-optic probe

In the present work we study the use of near infra-red spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe for the analysis of the mineral composition of animal feeds. The method allows immediate control of the feeds without prior sample treatment or destruction through direct application of the fibre-optic probe on the sample.The regression method employed was modified partial least squares (MPLS). The calibration results obtained using forty samples of animal feeds allowed the determination of Fe, Mn, Ca, Na, K, P, Zn and Cu, with a standard error of prediction (SEP(C)) and a correlation coefficient (RSQ) of 0.129 and 0.859 for Fe; 0.175 and 0.816 for Mn; 5.470 and 0.927 for Ca; 2.717 and 0.862 for Na; 4.397 and 0.891 for K; 2.226 and 0.881 for P; 0.153 and 0.764 for Zn, and 0.095 and 0.918 for Cu, respectively.The robustness of the method was checked by applying it to 10 animal feeds samples of unknown mineral composition in the external validation.     

(α + γ<Subscript>1</Subscript>) Complex phase formation in the Cu-10 mass% Al-6mass% Ag alloy

In this work the (α + γ₁) complex phase formation reaction in the Cu-10mass% Al-6mass% Ag alloy was studied using Differential Scanning Calorimetry (DSC), Differential Thermodilatometry (DTD), X-ray diffractometry (XRD), Optical (OM) and Scanning Electron Microscopies (SEM). The results indicated the presence of two different processes, related to a change in the Ag diffusion route from the α matrix to the (α + γ₁) complex phase.