The certification of major components and major elements in five food reference materials

Summary The development of five food reference materials (whole milk powder, pork muscle, rye and wheat flour, and haricot beans) is described. Homogeneity and stability of three categories of nutrients, major components, major elements and vitamins, proved to be adequate. Certification of Kjeldahl nitrogen, total fat, lactose, total dietary fibre (AOAC method), ash, Na, K, Mg, Ca, and Cl contents was successful. In contrast, only indicative values could be given for starch and sugars, nonstarch polysaccharides and P because of insufficient agreement between laboratories. The measurement of these components and elements need further study to obtain the improvement needed. Indicative values for retinol, -carotene, -tocopherol, vitamin B₁, vitamin C, and niacin in some of these materials could be given. Prospects for future certification of vitamins are favourable.     

Reactions of superoxide anion radical with antioxidants and their use in voltammetry

Kinetic parameters were calculated for the electrochemical reduction of oxygen at a glassy-carbon electrode with the generation of superoxide radical anions in a 0.05 M solution of (C₂H₅)₄NI in dimethylformamide in the presence of fat-soluble antioxidants, retinol and -tocopherol. A procedure based on the protonation of the radical anion with antioxidant molecules is proposed for the voltammetric determination of antioxidants to determine milligram amounts of retinol and -tocopherol in model solutions (RSD = 1–2%). The calibration graphs for retinol and -tocopherol are linear in the concentration ranges 9.7 × 10^–5–2.3 × 10^–3 and 6.2 × 10^–4–3.1 × 10^–3 M, respectively. The detection limits for retinol and -tocopherol are 4.8 × 10^–5 and 4.1 × 10 ^–4 M, respectively. The procedure was applied to the determination of the active component (retinol and -tocopherol) in pharmaceuticals.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 1, 2005, pp. 56–59.Original Russian Text Copyright © 2005 by Ziyatdinova, Gilmetdinova, Budnikov.     

Triterpene glycosides of alfalfa. III. Medicoside I

On the basis of chemical transformations and with the aid of physicochemical results, the structure of glycoside I isolated from the roots of the plantMedicago sativa has been established as hederagin 3-O-[O--L-arabinopyranosyl-(1 2)--D-glucopyranosyl-(1 2)--L-arabinopyranoside] 28-O--D-glucopyranoside. Compound (I), C₅₂H₈₄O₂₂, mp 210–212°C, [] _D ²¹ +38.4° (c 1.48; methanol). Acid hydrolysis of (I) led to hederogenin (II) — C₃₀H₄₈O₄, mp 326–330°C, [] _D ²³ +84.2° (c 0.19; pyridine. The Hakomorimethylation of glycoside (I) yielded the permethylate (IV) — C₆₅H₁₁O₂₂ [] _D ²³ +41.6° (c 1.79; methanol). The GLC analysis of the products of the methanolysis of compound (IV) showed the presence of 3,4,6-tri-O-methyl-D-glucopyranose, 2,3,4,6-tetra-O-methyl-D-glucopyranose, 3,4-di-O-methyl-L-O-arabinopyranose, and 2,3,4-tri-o-methyl-L-arabinopyranose. The alkaline hydrolysis of glycoside I gave compound (III) with mp 230–233°C, [] _D ²¹ +35.2° (c 0.21; methanol), which was identified as medicoside C. Details of the PMR spectrum are given for compound (IV) and of the IR spectrum for compound (I).Institute of the Chemistry of Plant Substances of the Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 607–610, September–October, 1986.     

Determination of Some Liposoluble Antioxidants by Coulometry and Voltammetry

It is found that the interaction of retinol, ergocalciferol, and cholecalciferol with electrochemically generated bromine proceeds rapidly and quantitatively. The stoichiometric coefficients of the reaction are 1 : 2, 1 : 7, and 1 : 3, respectively. A coulometric determination of microgram amounts of individual liposoluble antioxidants in model solutions was performed with RSD = 1–5%. The voltammetric response of retinol and -tocopherol was studied at a stationary platinum microelectrode in 0.1 M HClO₄ and 0.1 M CH₃COONa in acetonitrile. The quantification limit for -tocopherol is 2.7 × 10^–4 M in 0.1 M HClO₄, and the quantification limits for retinol are 4.1 × 10^–5 M in 0.1 M HClO₄ and 2.1 × 10^–5 M in 0.1 M CH₃COONa. A procedure for the coulometric determination of total free liposoluble antioxidants in human blood serum is proposed.     

Some problems associated with the use of boron carbide neutron filters for reactor epithermal neutron activation analysis (ENAA)

The radiation heating caused by the¹⁰B(n, )⁷Li-reaction in boron carbide (B₄ C) neutron filters used for epithermal neutron activation analysis has been examined by measuring rates of temperature rise and steady-state temperatures of sintered and powdered B₄C filters placed in dry air and reactor pool-water during irradiation, respectively. Maximum equilibrium temperatures of 195°C for air-cooled sintered, and 50°C for water-cooled powdered B₄C were observed, confirming the necessity for efficient cooling of the filter during irradiation. It is noted that the accumulation of the¹⁰B(n, )⁷Li-reaction products in B₄C and other boron compounds may severely limit the reuse of the filters in subsequent irradiations.     

A chemical investigation ofAchillea nobilis

From the flower heads and leaves ofAchillea nobilis collected in the flowering phase close to Balytkykol, Egindybulak region, Karaganda Province, Kazakh SSR, by extraction with chloroform and chromatography of the combined substances on a column of silica gel we have isolated a new sesquiterpene lactone anobin C₁₅H₂₀O₅, mp 175.5–177.5°C and have identified for the first time estafiatin, C₁₅H₁₈O₃, mp 102–104°C []²⁰ –10.3° (chloroform); hanphyllin, C₁₅H₂₀O₃, mp 189°C (decomp), [] _D ²⁰ + 58.6° (c 0.39; chloroform), and 3,5-dihydroxy-6,7,8-trimethoxyflavone, C₁₈H₁₆O₇, mp 148–150°C. On the basis of chemical and spectral characteristics it has been established that anobin has the structure of 4,10-dihydroxy-2,3-epoxy-5,7(H),6(H)-guai-11(13)-en-6,12-olide. It has been established that estafiatin possesses a pronounced growth regulating activity.Deceased.Chemical and Metallurgical Institute, Academy of Sciences of the Kazakh SSR, Karaganda. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 603–607, September–October, 1984.     

Enthalpy of solution of carbohydrates using a modified differential scanning calorimeter

A differential scanning calorimeter (DSC) was modified for the determination of enthalpies of solution. The measurements were performed on aqueous solutions of the deoxy- and fluoro-deoxy derivatives of D-glucopyranose (Glu) where the OH group on the C1, C2, C3, and C6 is replaced by H (1HGlu, 2HGlu, 3HGlu, and 6HGlu) and by F (1FGlu, 2FGlu, 3FGlu, and 6FGlu), 4-deoxy 4-fluoro--D-glucopyranoside (4FGlu), 1-methoxy--D-glucopyranoside (MeOGlu), 1-phenoxy--D-glucopyranoside (PheOGlu), D-mannopyranose (Man), and 3-methoxy--D-glucopyranoside (3MeOGlu), at 15.1, 25.0, 35.0, and 45.1°C. The enthalpies of solution _sH⁰(T) ranged from 1.00±0.25 kJ-mol^–1 for 6HGlu at 15.1°C to 20.4±1.4 for PhOGlu at 45.1°C and were in good agreement with literature values for Man, Glu, MeOGlu, and 3MeOGlu at 25.0 and 35.0°C and for MeOMan and 2HGlu at 35.0°C. _sH⁰(T) for the derivatives were then extrapolated up to the melting temperature T_m and compared with their enthalpies of fusion, _fH also determined from DSC measurements. If the agreement between _sH⁰(T_m) and _fH was within the 95% confidence level, then it was concluded that intermolecular interactions between the carbohydrate molecules in the liquid phase were the same as between the carbohydrate and water molecules in the solution phase. This agreement was observed for aqueous solutions of Man, Glu, MeOGlu, 3HGlu, 3FGlu, and 6FGlu.     

Protonation of pyrrolo [1,2-α] Pyrimidine derivatives

The protonation of pyrrolo [1,2-] pyrimidine and 6, 7, 8, 9-tetrahydropyrimido [1, 2-] indole derivatives in CF₃COOH (at –15 to +25° C) and in CF₃COOH/H₂SO₄ (at 25°) was studied by PMR spectroscopy. The investigated compounds form monocations, the structure of which corresponds to the addition of a proton to the carbon atom of th pyrrole fragment in the position to the bridge nitrogen atom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 686–692, May, 1976.     

Cardiac glycosides ofAcokanthera venenata

Six cardenolides have been isolated from the leaves ofAcokanthera venenata G. Don: AV-1, mp 252–255°C, [] _D ²⁰ +39.4° (MeOH); AV-2, mp 199–208°C, [] _D ²⁰ -59.3° (MeOH); AV-3, mp 269–275°C/300–304°C, [] _D ²¹ –69.8° (MeOH); AV-4, mp 279–289°C; AV-5, mp 222–225°, [] _D ²⁰ -64.3° (MeOH); and AV-6, mp 193–196°C [] _D ²⁰ –23.8° (MeOH — CHCl₃). AV-5 has been identified as acovenoside A. AV-3 is a new cardiac glycoside: it is 1-acetoxy-3-(4-O--D-glucosyl-3-O-methyl--L-talomethylosyloxy)-14-hydroxy-5, 14-card-20(22)-enolide (glucoacovenoside B).Khar'kov State Pharmaceutical Institute. All-Union Scientific Research Institute of Drug, Chemistry and Technology, Khar'kov. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 372–376, May–June, 1987.     

Formation of α-Alumina Around 500°C in Alkoxy-Derived Alumina Gels Under Ambient Pressure—Effects of Starting Solution Composition and Seeding

The hydrolysis of aluminum-sec-butoxide (ASB) in the ASB-H₂O-C₂H₅OH-HCl solutions at 0°C for 18 h and subsequent aging of the sol for 30 days at 5°C provided an alumina gel which was partially (20–30 wt%) transformed to -Al₂O₃ when heat-treated at 500°–600°C under ambient pressure. In addition to the hydrolysis and aging conditions, the amounts of water and HCl in the starting solution were found to be very important factors for the low temperature formation of -Al₂O₃ in the resultant gel. Some difference in the chemical environment of involved OH groups was found between the alumina gel forming -Al₂O₃ at 500°–600°C and the conventional gel. Corundum seeding was found to be effective; thus, 1 wt% seeding brought about an increase in the fraction of -Al₂O₃ formed at 600°C to 40–50 wt%.     

Volumes of mixing of pyridine bases withn-alkanes: Comparison with the prigogine-flory-patterson theory

The excess molar volumes of binary mixtures pyridine and -picoline + C₆–C₁₀ n-alkanes have been measured at 25°C over the whole composition range. For pyridine + n-hexane and + n-heptane and also -picoline + n-hexane and n-heptane V ^E has an S-shaped behavior and is positive at low concentrations of the base. For the systems pyridine + n-octane + n-nonane + n-decane and -picoline + n-octane, n-nonane, and n-decane V ^E is positive. The Prigogine-Flory-Patterson theory has been fitted to our results.     

Negativer linearer thermischer Ausdehnungskoeffizient von verstrecktem Polyäthylen

Zusammenfassung Der lineare thermische Ausdehnungskoeffizient von linearem Polyäthylen hoher Dichte wurde im Temperaturbereich –20 °C bis + 40°C bestimmt. Bei isotropen Proben besteht eine lineare Beziehung zwischen Dichte bzw. Kristallisationsgrad _v und. Die gemessenen Koeffizienten liegen fürT ₀ = 20 °C im Bereich = 110 ... 130 · 10^–6 K^–1.Kalt verstreckte Proben mit Verstreckungsgraden = 8 ... 15 haben beiT ₀ = 20 °C in Verstreckrichtung den Koeffizienten _l = –24 · 10^–6 K^–1. Der negative Zahlenwert von _tl ist unabhängig von und weiteren Herstellungsparametern. Seine Ursache ist einerseits die Orientierung derc-Achsen der Kristallite in Verstreckrichtung mit _c = –12 · 10^–6 K^–1 und andererseits der negative Koeffizient _am * –50 · 10^–6 K^–1 der verspannten amorphen Phase, der auf dem gummielastischen Verhalten der tie-molecules beruht.Beim Tempern oberhalb von +40 °C schrumpfen die Proben irreversibel, wobei _| ansteigt und nach dem Aufschmelzen der Proben wieder den Wert des isotropen Materials annimmt. Nach dem Tempern wenig unterhalb der Schmelztemperatur der Kristallite wurden überhöhte Koeffizienten _| gemessen, die eine Rotation der Kristallite um dieb-Achsen erkennen lassen.

---

Summary The linear thermal coefficient of expansion,, of high density linear polyethylene has been determined in the temperature range of –20 ° ... + 40 °C. For isotropic samples a linear relationship between density or crystallinity _v and is valid. Measured values of forT ₀ = 20 °C amount to = 110 ... 130 · 10^–6 K^–1.Cold drawn samples of draw ratios = 8 ... 15 yield _| = –24 · 10^–6 K^–1 atT ₀ = 20 °C parallel to the draw axis. The negative value of _| does not depend on draw ratio or other parameters of sample processing. It is caused byc-axis orientation of the crystallites in draw direction with _c = –12 · 10^–6 K^–1 and by a negative coefficient _am * = –50 · 10^–6 K^–1 of the stressed amorphous phase, which is due to rubber elastic behaviour of the tie molecules.When annealed above 40 °C the samples shrink irreversibly and _| is augmented. After melting the samples the value of isotropic material is restored. Annealing the samples little below the melting temperature of the crystallites leads to superelevated values all which reflect| rotation of the crystallites around theb-axis.

     

The solid state and solution chemistry of dichlorobis(α-picoline)-cobalt(II)

Summary The thermal decomposition of [CoCl₂(-pic)₂] was investigated over the 108°C to 222°C range and the Intennediates CoCl₂(-pic) (s) and CoCl₂ (s) were observed, with the evolution of (-pic) (g). Quantitative thermodynamic and kinetic data were obtained by performing dynamic and isothermal studies on the complex Additional thermodynamic data were obtained by studying the CoCl₂/-pic system in acetone. The effect of the methylsubstituent on the metal-donor-N bond as well as on the thermodynamic quantities were discussed.     

Diastereoselective addition of organomanganese compounds to chiral polyalkoxyaldehydes

Organomanganese compounds RMnI (R=Me, Pr, Bu, Hex, Ph, BuCC) prepared from RLi and MnI₂ in Et₂O react with 3-O-benzyl-1,2-O-isopropylidene--D-xylo-pentodialdo-1, 4-furanose, 1,23,4-di-O-isopropylidene--D-galacto-hexodialdo-1,5-pyranose, andR-2,3-dibenzyloxypropanal to afford 4,5-threo-, 5,6-threo-, and 2,3-threo-isomeric products, respectively, with high diastereoselectivity.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1122–1126, June, 1993.     

Triterpene glycosides of Astragalus and their genins. XX. Cycloorbigenin from Astragalus orbiculatus

A new genin — cycloorbigenin (I), C₃₀H₄₈O₅, mp 217–219°C, [] _D ²⁰ +28.3° (c 1.19; ethanol) has been obtained from a glycoside isolated from the epigeal parts of the plantAstragalus orbiculatus (Leguminosae), and on the basis of chemical transformation and spectral characteristics its structure has been established as 16,23:16,24-diepoxy-23(R),24(S)cycloartane-3,7,25-triol. The acetylation of (I) with acetic anhydride in pyridine yielded its diacetate (II), C₃₄H₅₂O₇, mp 148–150°C, [] _D ²⁰ +32.6° (c 0.92; methanol) and its triacetate (III), C₃₆H₅₄O₈, mp 137–139°C, [] _D ²⁰ +75° (c 0.4; methanol). The Jones oxidation of (I) led to a diketone (IV), C₃₀H₄₄O₅, mp 155–158°C, [] _D ²⁰ -73° (c 0.63; methanol). Details of the PMR, IR, and mass spectra are given for all the compounds.Institute of The Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 455–460, July–August, 1986.     

Triterpene glycosides ofAstragalus and their genins. XII. Askendoside B fromAstragalus taschkendicus

On the basis of chemical transformations and with the aid of physicochemical characteristics it has been established that a new glycoside of the cycloartane series — askendoside B (I) — isolated from the roots ofAstragalus taschkendicus Bge., is 20S,24R-epoxycycloartane-3,6,16,25-tetraol 3-0-[0--L-arabinopyranosyl-(1 2)-(3-0-acetyl--D-xylopyranoside)] 6-0--D-xylopyranoside, C₄₇H₇₆O₁₈, mp 215–218°C, [] _D ²⁰ –45.5° (c 1.1; pyridine). The acid hydrolysis of (I) yielded cyclosiversigenin (II) with mp 239–241°C, [] _D ²⁰ +54.5° (c 1.2; MeOH), and cyclosiversigenin 3-0--D-xylopyranoside (III) with mp 262–264°C, [] _D ²⁰ +41° (c 0.4; MeOH). The periodate oxidation of glycoside (I) followed by acid hydrolysis likewise led to (II) and to D-xylose. The alkaline hydrolysis of (I) yielded askendoside D (IV), with mp 235–236°C, [] _D ²³ –8.5° (c 1.0; pyridine). The Smith degradation of (I) led to (III). The IR and PMR spectra of (I) are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 457–460, July–August, 1983.     

Phytoecdysteroids of plants of the genusSilene X. Sileneoside E — 2-Deoxy-α-ecdysone 3-O-β-D-glucopyranoside — FromSilene brahuica

A new ecdysteroid has been isolated from the epigeal organs ofSilene brahuica Boiss. — 2-deoxy--ecdysone 3-O--D-glucopyranoside (I), C₃₃H₅₄O₁₀, mp 195–196°C, [] _D ²⁰ + 44.4° (methanol). The enzymatic hydrolysis of (I) led to 2-deoxy--ecdysone. Details of the IR, UV, mass, and¹H and¹³C NMR spectra of all the compounds are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 323–326, May–June, 1986.     

Withasteroids ofPhysalis VI.1H and13C NMR spectra of withasteroids ixocarpalactone A and ixocarpanolide

The¹H and¹³C NMR spectra of two withasteroids isolated fromPhysalis ixocarpa Brot. have been studied in detail. Their spectral characteristics are discussed. A comparison of the results obtained has led to the identification of a withasteroid with the composition C₂₈H₄₀O₈, mp 291–292°C (from methanol) as ixocarpalactone A, in spite of some difference in its physical constants. The other compound, with mp 252–253°C (from methanol), had the composition C₂₈H₄₀O₆, [] _D ²⁰ +27±4°, is new and has been called ixocarpanolide. The structure of 5,20R-dihydroxy-1-oxo-6, 7-epoxy-22R-witha-2-enolide has been proposed for it.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 326–332, May–June, 1986.