Reference intervals of serum folate and vitamin B12 developed from data of healthy subjects

 In this study the reference intervals for folate and vitamin B₁₂ were estimated according to the National Committee for Clinical Laboratory Standards Approved Guideline C28-A and International Federation of Clinical Chemistry recommendations. The study included 155 women and 124 men between ages 18–40. The health status was confirmed by history, physical examination and a questionnaire. The central 95% reference intervals of serum folate and vitamin B12 for women, determined non-parametrically, were found to be 3.9–18.1 ng/ml and 101–666.7 pg/ml, respectively. The reference values of serum folate and vitamin B12 for men were also found to be 2,5–17.6 ng/ml and 100–699.57 pg/ml, respectively. We did not observe subclass differences between females and males. Received: 15 April 2000 · Accepted: 15 April 2000     

12-Epinapelline and its N-oxide fromAconitum baicalense

12-Epinapelline and its N-oxide have been isoated from the epigeal part ofAconitum baicalense Turcz. ex Rapaics (A. Czekanovskyi Steinb.). The structures of these compounds have been determined with the aid of two-dimensional¹H and¹³C NMR spectroscopy, and IR and mass spectrometry. Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 888–892. November–December, 1993.     

Povarov Reaction of Glyoxylate Imines Derived from 12-Aminodehydroabietic Acid

Glyoxylate and arylglyoxal imines based on 12-aminodehydroabietic acid undergo hetero-Diels—Alder (Povarov) reaction with ethyl vinyl ether, cyclopentadiene, and indene to give, respectively, methyl (8aR,9R,12aS)-3-aroyl-5-isopropyl–9,12a-dimethyl–7,8,8a,9,10,11,12,12a-octahydronaphtho[1,2-f]quinoline-9-carboxylates, methyl (7R,10aS,10dR,13aS)-1-aroyl–3-isopropyl–7,10a-dimethyl–2,5,6,6a,7,8,9,10,10a,10d,13,13a-dodecahydro-1H-naphtho[1,2-f]cyclopenta[c]quinoline-7-carboxylates, and methyl (6aS,11bS,11eS,15R,15aR)-6-aroyl–4-isopropyl–11e,15-dimethyl–2,5,6,6a,7,11b,11e,12,13,14,15,15a-1H-dodecahydroindeno[2,1-c]-naphtho[1,2-f]quinoline-15-carboxylates.     

Thermal analysis of the ω nanophase transformation from the metastable β Ti–12Mo alloy

In this study, the thermal analysis of the ω nanophase transformation from a quenched metastable β Ti–12Mo alloy composition (mass%) was investigated by electrical resistivity and dilatometry measurements. The activation energy was observed to be 121 ± 20 kJ mol⁻¹ (from resistivity measurements) and 114 ± 12 kJ mol⁻¹ (from dilatometry measurements) during the early stage of the transformation process. The kinetic of the ω nanophase transformation was modelized by using the classical Johnson–Mehl–Avrami (JMA) theory and a modified Avrami (MA) analysis. An Avrami exponent close to 1.5 was found at the early stage of the transformation suggesting a pure growth mechanism from pre-existing nucleation sites. Nevertheless, it was observed a decrease of the Avrami exponent to 0.5 at higher transformed fraction demonstrating a dimension loss in the growth mechanism due to the existence of the high misfit strain at the interface β/ω.     

Compounds of the [PMo12O40]3− anion with surfactant cations forming nanoperiodic structures

Phosphomolybdic acid forms compounds with surfactant cations in acid aqueous media (pH 1.0–2.5) to give compounds A₃[PMo₁₂O₄₀] or Etn₃[PMo₁₂O₄₀]₂·nEtnCl₂ (n=0−3) with various nanoperiodicity depending on the surfactant and synthesis conditions. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 34, No. 3, 184–190, May–June, 1998.     

Efficient Routes to ω-Chloroalkyl Bilirubins and C12-N22 Bridged Biliverdins

 ω-Chloroalkyl biliverdins, prepared in three steps from 8-unsubstituted dipyrrinones in 70–80% overall yields, were reduced by sodium borohydride to provide the corresponding ω-chloroalkyl bilirubins in high yields. Upon treatment of the ω-chloroalkyl biliverdins with sodium hydroxide in ethanol, C12-N22 bridged biliverdins were obtained in high yields.     

Observation of a Doppler broadening of the 4438 keV gamma-line of12C in processes12C(n,n′γ)12C and9Be(α, nγ)12C

A Doppler broadening is described of the 4438 keV spectral gamma-line observed by means of a Ge(Li) detector during the deexcitation of nuclei of¹²C in an inelastic scattering¹²C(n, n′γ)¹²C using an²⁴¹Am−Be source as well as during the reaction⁹Be(α, nγ)¹²C taking place in the Am−Be source. The FWHM of the spectral line is equal to (90±4) keV in the latter reaction and (64±8) keV in the former process. Experimental values agree well with theoretical ones. Presented at the Instrumental Activation Analysis Conference, IAA 79, June 4–8, 1979, Klučenice, Czechoslovakia.     

Efficient Routes to ω-Chloroalkyl Bilirubins and C12-N22 Bridged Biliverdins

Summary.  ω-Chloroalkyl biliverdins, prepared in three steps from 8-unsubstituted dipyrrinones in 70–80% overall yields, were reduced by sodium borohydride to provide the corresponding ω-chloroalkyl bilirubins in high yields. Upon treatment of the ω-chloroalkyl biliverdins with sodium hydroxide in ethanol, C12-N22 bridged biliverdins were obtained in high yields. Received December 13, 2000. Accepted January 15, 2001     

Chemotypical Variability of Leaf Oils in <Emphasis Type="Italic">Elephantopus scaber</Emphasis> from 12 Locations in China

The chemical constituents of leaf oils of Elephantopus scaber L. from 12 locations in Southern China, including three provinces and Hong Kong, were investigated using GC/MS. A total of 24 compounds were detected, of which 20 were identified by their mass spectra fragmentation patterns. The major compounds include hexadecanoic acid (8.19–39.22%), octadecadienoic acid (trace - 29.22%), five alkane homologues, i.e., n-tetradecane (1.19–5.26%), n-pentadecane (3.22–12.05%), n-hexadecane (2.38–16.26%), n-heptadecane (2.48–15.32%), and n-octadecane (1.39–9.59%), as well as tetramethylhexadecenol (2.06–4.31%). Hierarchical cluster analysis classified the leaf oils into two groups. Two main chemotypes of leaf oils in E. scaber were thus identified, one rich in hexadecanoic acid and octadecadienoic acid, and the other rich in the five alkane homologues. __________ Published in Kimiya Prirodnikh Soedinenii No. 5, pp. 403–404, September–October, 2005.     

Features of laser desorption/ionization mass spectrometry fragmentation of vitamin B<Subscript>12</Subscript>

A comparative analysis of the laser desorption/ionization of vitamin B₁₂ by matrix-assisted laser desorption/ionization (MALDI) and desorption/ionization on porous silicon (DIOS) was carried out. The mass spectra obtained were interpreted and the pathways for ion formation and decomposition were established. The MALDI fragmentation of the positive vitamin B₁₂ ions is more extensive than the DIOS fragmentation. The most extensive fragmentation was found using the MALDI method for negative vitamin B₁₂ ions, which are lacking when using the DIOS method. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 4, pp. 251–256, July–August, 2007.     

Temperature dependence of the ratios of the rate constants of hydroxylation of the cycloalkanes C6H12/C6D12 and C5H10/C6H12 in sulfuric acid

The temperature dependence of the ratios of the rate constants k(C₅H₁₀)/k(C₆H₁₂) and k(C₆H₁₂)/k(C₆D₁₂) for the reaction of the cycloalkanes C₅H₁₀, C₆H₁₂, and C₆D₁₂ with OH⁺ cations in the system (NH₄)₂S₂O₈ (0.1 mol/kg)-H₂SO₄ (94.4 mass %) in the 6–50 °C range has been studied. The activation energies found E(C₆H₁₂) − E(C₅H₁₀) = − 5.3 ± 0.3 and E(C₆D₁₂) − E(C₆H₁₂) = 7.9 ± 0.7 (kJ/mol) permits the comparison of OH⁺ to a group of reagents (NO₊², Pd²⁺, HSO₊³) which interact with the C-H bond via an electrophilic substitution mechanism. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 44, No. 6, pp. 354–358, November–December, 2008.     

Acylation of [B12H12]2− dianion by carboxylic acid halides

The sodium salt of [B₁₂H₁₂]²⁻ dianion reacts with carboxylic acid halides to give a mixture of B-acylated product [B₁₂H₁₁COR]²⁻ and an unstable intermediate, the latter undergoing hydrolysis to form [B₁₂H₁₁OH]²⁻. The ratio of the products formed depends on the nature of the radical R. The reaction mechanism was studied by NMR spectroscopy. A number of novel [B₁₂H₁₁COR]²⁻ compounds were synthesized; their structures were confirmed by NMR and IR spectral data. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 980–985, May, 1998.     

Efficient synthesis of onoceranediol from 12-hydroperoxy-8α,12-epoxy-11-bishomodrimane

An efficient one-step synthesis of the diacetate of the tetracyclic triterpenoid onoceranediol (4) by radical cleavage of the readily available 12-hydroperoxy-8α,12-epoxy-11-bishomodrimane is described. Drim-9(11)-en-8α-yl acetate (7) is formed in this reaction as a byproduct. Onoceranediol diacetate 4 is converted into onoceranediol on treatment with LiAlH₄, and acetate 7 is transformed into drim-9(11)-en-8α-ol on saponification. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2571–2573, November, 2005.     

Electrochemical behavior and stability of Li4Ti5O12 in a broad voltage window

Electrochemical behavior and stability of spinel Li₄Ti₅O₁₂ are investigated in a broad voltage window (0.0–5.0 V vs. Li/Li⁺). The voltage profile of the Li₄Ti₅O₁₂ electrode shows a plateau region at 1.55 V and two sloped regions below 1.55 V when the electrode is cycled between 0.0 and 2.0 V. It is found that Li₄Ti₅O₁₂ maintains high lithium storage characteristic with the increase of the current density. Moreover, Li₄Ti₅O₁₂ shows excellent rate performance in 0.0–2.0 V and good cyclic performances in 0.0–4.0 and 1.0–5.0 V. Besides, the crystal structure is kept when it is cycled between 0.0 and 5.0 V.     

Kinetics and mechanism of the reactions of C6H12, C5H10 and C6D12 cycloalkanes with peroxynitrous acid in aqueous solution and the gas phase

The c-C₆H₁₂/c-C₆D₁₂ kinetic isotope effect (KIE), the k₆/k₅ rate constant ratio (c-C₆H₁₂/c-C₅H₁₀), and the temperature dependence of these ratios in the gas-phase reactions of cycloalkanes with peroxynitrous acid and OH radicals are identical. The same result was obtained for the reactions in aqueous solution. These data are in accord with the conclusion that OH^· radicals formed in the homolysis of the HO-ONO bond are the active species in the reactions of HOONO with hydrocarbons in aqueous solution and in the gas phase. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 44, No. 2, pp. 105–110, March–April, 2008.     

Preparation and Crystal Structure of K2Ag12Te7

Summary.  Single crystals of K₂Ag₁₂Te₇ (a = 11.460(2), c = 4.660(1) ?; V = 530.01 ?³; space group: P6₃/m; Z = 1) were synthesized under hydrothermal conditions at 250°C in concentrated aqueous KOH solution from elementary silver and tellurium. The crystal structure is characterized by trigonal prismatic KTe₆ polyhedra, connected via two common faces to KTe₃ rods parallel to [001]. These rods are combined by two crystallographically independent Ag atoms, each coordinated to four Te and three Ag atoms (Ag–Te and Ag–Ag < 3.1 ?) to a framework of the formula (K₂Ag₁₂Te₆)^2 + and with channels parallel to the sixfold axis. These channels are statistically occupied by one further Te atom per unit cell, distributed over two independent positions. Received May 17, 2001. Accepted (revised) July 3, 2001     

Synthesis of 3β,20S-dihydroxydammar-24-en-12-one 3,20-di-O-β-D-glucopyranoside (chikusetsusaponin-LT8), a glycoside from Panax japonicus

A method for preparative production of 3β,20S-dihydroxydammar-24-en-12-one 3,20-di-O-β-D-glucopyranoside (1), a glycoside from Panax japonicus, chikusetsusaponin-LT₈ was developed. Chemical transformation of betulafolientriol, a component of Betula leaves extract, produced the 12-keto-20S-protopanaxadiol (3β,20S-dihydroxydammar-24-en-12-one) (2), exhaustive glycosylation of which by 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosylbromide (3) under Koenigs—Knorr reaction conditions with subsequent removal of protecting groups formed 3β,20S-dihydroxydammar-24-en-12-one 3,20-di-O-β-D-glucopyranoside (1). The principal glycosylation product was 3β,20S-dihydroxydammar-24-en-12-one 3-O-β-D-glucopyranoside if equimolar amounts of (2) and (3) were used. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 44–48, January–February, 2006.     

Synthesis of succinic acid 12α-deoxoartemisinyl ester 4′-O-demethyl-4β-(4″-nitroanilino)-4-desoxypodophyllotoxin

The succinic acid 12α-deoxoartemisinyl ester 4′-O-demethyl-4-β-(4″-nitroanilino)-4-desoxypodophyllotoxin was synthesized for the first time. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 442–443, September–October, 2007.     

Determination of vitamin B12 in pharmaceutical preparations by a highly sensitive fluorimetric method

A fluorimetric method for the determination of vitamin B₁₂ has been developed. The fluorescence emission was measured at λ_ex/λ_em275/305 nm in phosphate buffer solution (pH 7.0), and the experimental variables and possible interference were studied. The linear calibration range was 1.000 ng/mL to 100.0 ng/mL with a correlation coefficient of 0.9994 and a detection limit of 0.1 ng/mL. The method is rapid, simple and highly sensitive. It was used to determine vitamin B₁₂ in pharmaceutical preparations. The recovery was 96%–98% and the relative standard deviation was in the range of 1.8%–2.7%. The results agreed with those obtained by spectrophotometry. Received: 17 July 2000 / Revised: 4 September 2000 / Accepted: 7 September 2000     

The transition of three types of three-phase behavior in a temperature-composition space of water/C12EO6/propanol/heptane system

 The change of three-phase behavior of a water/hexaethylene-glycol dodecyl ether (C₁₂EO₆)/propanol/heptane system was studied with increasing temperature (30.0–48.9 °C). A cone-like three-phase body consisting of aqueous (W), surfactant (D_p), and oil (O) phases is formed in the composition tetrahedron at lower temperatures. The body is expanded with increasing temperature, and touches the water–C₁₂EO₆–heptane triangle (the base) at 44.8 °C. At about 45.6 °C the loci of the D_p and O phases meet and cut off at a critical double end point and the three-phase body separates into two bodies: one has a chiral shape and the other is unclosed. The unclosed body is transformed with the change of shape of the tie triangle on the base as temperature increases and leaves from the base at 48.9 °C. A closed-loop miscibility gap between middle surfactant (D^′ _p) and O phases or a cone-like three-phase body is formed inside the composition tetrahedron at higher temperatures. The roles of C₁₂EO₆ and propanol are also discussed. Received: 14 April 1998 Accepted: 15 July 1998