Polymers from 12-hydroxymethyltetrahydroabietic acid and its vinyl and acrylate esters

12-Hydroxymethyltetrahydroabietic acid has been homopolymerized by melt condensation and homopolyester has been obtained. Vinyl 12-hydroxymethyltetrahydroabietate has been prepared from 12-hydroxymethyltetrahydroabietic acid by vinyl interchange procedure with vinyl acetate, and has been homopolymerized, copolymerized with vinyl chloride, vinyl acetate, and terpolymerized with styrene and acrylonitrile. The acrylate ester of 12-hydroxymethyltetrahydroabietic acid also has been prepared from 12-hydroxymethyltetrahydroabietic acid and acrylyl chloride. The acrylate thus obtained has been homopolymerized and copolymerized with vinyl chloride and vinyl acetate. Polymers thus obtained have been characterized.     

Characterization, via ESR spectroscopy, of radical intermediates in the photooxidation of arylcarbinols by ceric ammonium nitrate

The photooxidation by ceric ammonium nitrate (CAN) of several aryl and naphthylcarbinols has been studied by means of ESR spectroscopy. For all the investigated arylcarbinols, but not for the naphthyl derivatives, it has been possible to detect radical intermediates deriving from the parent alkoxyl radicals. In particular, in the photooxidation of 1,1-diphenylethanol, a bridged-radical intermediate has been detected. The assignment has been validated through experiments with two different labeled compounds: the 1,1-[2', 3', 4', 5', 6', 2", 3", 4", 5", 6"-2H10]diphenylethanol and the 1,1-diphenyl[2, 2, 2-2H3]ethanol. A similar bridged radical has been found to be formed in the photooxidation of triphenylmethanol, while, for the 1,1-diphenylpropanol, the only detectable species has been the ethyl radical deriving from a competitive beta-scission process. Finally, for the 2-phenylpropan-2-ol (cumyl alcohol), two radical species have been identified: the methyl, deriving from the beta-scission process, and the cyanomethylene, deriving from H-abstraction of the cumyloxyl radical from the solvent. A kinetic study on the competition of the two processes has also been conducted and the parameters of the Arrhenius equation for the latter process have been estimated.     

On the electrochemical characterization of ion-selective cellulose acetate membranes with and without stigmasterol liquid membranes

Stigmasterol, a plant product, has been used as a surfactant to generate liquid membranes supported on a cellulose acetate matrix. Electrochemical characterization of the membrane has been attempted with a view to simulating its behavior with natural membranes by measuring membrane potentials and membrane conductance. The selectivity of cellulose acetate membrane kept in contact with magnesium chloride solutions of different mean concentrations has been found to change from anion to cation. Transport numbers have been estimated from membrane potential data. Permselectivity and fixed charge density values for the cellulose acetate membrane with and without stigmasterol have been determined from transport numbers. The variation of these parameters with concentration and pH has also been examined.     

A new method for studying the influence of pollution and soil nature on the radon emanation from water samples by using solid state nuclear track detectors

Radon emanation from surface water and groundwater samples has been studied by using CR-39 and LR-115 solid state nuclear track detectors (SSNTD). A calibration method for determining the thoron and radon concentrations of the water samples studied has been developed. The effect of pollution due to coal fly ashes, cement and granite dusts on the radon emanation from water samples has been investigated. The influence of the radon source on the radon emanation rates from water samples has been studied.     

Ionization probability of the hydrogen atom suddenly released from confinement

The problem of the stability of a confined atom when it is extracted from the confining cavity has been investigated, modeled by a spherical hard wall potential. The ionization probability when the atom is released from confinement has been obtained. The dependence of the ionization probability on the confinement radius and on the quantum numbers of the initial confined state has been studied. The probability density function of the ionization energy of the ejected electron has been obtained for the different cases considered. The oscillatory structure of this distribution function, with a principal maximum located in the neighborhood of the energy of the initial state and minima very close to zero has been elucidated. The sudden approximation has been applied and the analytic continuation method has been used to calculate the different stationary states.     

Pseudoisocyanine J-aggregate to optical waveguiding crystallite transition: microscopic and microspectroscopic exploration

Using fluorescent microscopy and microspectroscopy, optical properties and morphology transformations in individual pseudoisocyanine (PIC) J-aggregates in aqueous electrolyte solutions have been explored. A stringlike structure of J-aggregates with a string diameter much less than 1 microm has been observed. Photodestruction of the strings under short-wavelength excitation has been revealed. Rodlike PIC crystallites, about 1 microm in diameter, have been observed with time. The fluorescence spectrum of rodlike crystallites has been found to differ from that of stringlike J-aggregate and from PIC crystal powder spectra. The crystallites are very stable, and their photodestruction has not been observed under any excitation conditions. It has been found that rodlike crystallites in contrast to stringlike J-aggregates possess optical waveguide properties. The luminescence of crystallites can be observed only at the excitation spot and at butt ends located up to hundreds of micrometers from the excitation spot.     

Separation of free iodide from other I-species in human serum – Quantification in serum pools and individual samples

A method for the determination of free iodide in human serum has been developed. Iodide from pooled serum samples has been separated from the organic matter by SEC, subsequently freeze-dried and analyzed by ion chromatography. Investigations for recovery and precision have been carried out and provided sufficient results. For quality assurance ICP-MS has been taken additionally as a total I-detector. The iodide results of ICP-MS agree well with IC values. Iodine containing SEC- fractions from iodide-spiked samples has shown no increased I-values except that in the iodide fractions, proving that there has been no iodide conversion into other I-species (and vice versa) during the whole procedure. Free iodide from two serum pools of different healthy persons has been determined as 2.25 and 2.43 microg I(-)/l, respectively. The values are related to total iodine levels determined by ICP-MS. For comparative reasons a table of individual iodine and iodide values is presented.     

Structure of 6-Epiforsticine and Revision of the Stereochemistry of Forsticine

In the course of our investigation on Aconitum and Delphinium species, we have isolated a number of norditerpenoid and diterpenoid alkaloids from A. kuzsnezoffii and A. hemsleyanum var. pengzhouense1~6. We have found that a norditerpenoid alkaloid, 6-epiforsticine isolated from both plants shows a great deal of similarity to forsticine7 but significantly differed from the latter in its 13C NMR spectrum (Table l), suggesting that the alkaloids were a pair of epimers at C-6. The present comm…     

Polyelectrolyte Configuration of Low Molecular Weight Sodium Amylose Xanthate in Aqueous and Salt Solutions

The polyelectrolyte chain configuration of low molecular weight sodium amylose xanthate (NaAX) in aqueous and salt solutions has been studied by viscometry and light scattering. The viscometric results in aqueous solution have been found to be in accordance with the Fuoss's modified equation. The intrinsic viscosities of NaAX in salt solutions from 0.00125 to 0.25 M NaCl have been determined and the expansion factor a at each ionic strength has been determined. The dependence of a on ionic strength has been studied according to the theories of Hermans and Overbeek, Flory, etc. But though qualitative agreement between experimental and theoretical results has been found, quantitative agreement was far from expectations. The frictional coefficient per monomer unit | has been calculated from the relationship of Kirkwood and Riseman. The NaAX macromolecule has been found to have the polydispersed random coil chain configuration in 0.25 M NaCl. Some macromolecular configurational parameters such as effective bond length b, Kuhn-Kuhn equivalent chain length A_m, and steric factor α has been determined.     

Fluoroquinolones in soils: Assessment of extraction methods

The extraction of six fluoroquinolones from agricultural soils with different physicochemical characteristics (pH, texture and organic carbon content) has been investigated. Different solvents, consisting of hydroorganic mixtures, have been tested, and basic buffer solutions, with either acetonitrile or acetone, have proved to be suitable extraction solvents. Conventional mechanical shaking and microwave-assisted extraction techniques have been evaluated, and mechanical shaking has been selected. Recovery rates from freshly spiked (overnight) soils ranged from 65 to 90%, depending on the quinolone. No relevant dependence on soil characteristics has been observed. The effect of ageing on the extraction behaviour of fluoroquinolones has also been considered. In comparison with freshly spiked soils, extractions from residues aged for some months have resulted in about 20–25% lower recovery rates.     

Hydrogen and higher shell contributions in Zn2+, Ni2+, and Co2+ aqueous solutions: an X-ray absorption fine structure and molecular dynamics study

A detailed investigation of the hydration structure of Zn2+, Ni2+, and Co2+ in water solutions has been carried out combining X-ray absorption fine structure (EXAFS) spectroscopy and Molecular Dynamics (MD) simulations. The first quantitative analysis of EXAFS from hydrogen atoms in 3d transition metal ions in aqueous solutions has been carried out and the ion-hydrogen interactions have been found to provide a detectable contribution to the EXAFS spectra. An accurate determination of the structural parameters associated with the first hydration shell has been performed and compared with previous experimental results. No evidence of significant contributions from the second hydration shell to the EXAFS signal has been found for these solutions, while the inclusion of the hydrogen signal has been found to be important in performing a quantitative analysis of the experimental data. The high-frequency contribution present in the EXAFS spectra has been found to be due to multiple scattering (MS) effects inside the ion-oxygen first coordination shell. MD has been used to generate three-body distribution functions from which a reliable analysis of the MS contributions to the EXAFS spectra of these systems has been carried out.     

The extractives of Vitex lucens—I

Vitexin, isolated from Vitex lucens, has been formulated as C₂₁H₂₀O₁₀ and, in agreement with recent workers, structure (I) has been assigned to the compound. β-sitosterol has been isolated from the heartwood.     

Normal coordinate analysis of 1,4-diethynylbenzene

Normal coordinate analysis has been carried out for the 1,4-diethynyl benzene molecule on the basis of experimental frequencies from the natural compound and its deuterated derivatives. A canonic force field has been set up by transferring force constants from related molecules. This force field has been refined to the experimental frequencies. A reassignment of the vibrational spectrum of 1,4-diethynyl benzene has been carried out.     

Reversed phase extraction chromatographic separation of ruthenium(III)

A new an innovative separation method has been developed using N-n-octylaniline (liquid anion exchanger) coated on silica gel. Ruthenium(III) has been extracted quantitatively from 0.05 M hydrochloric acid, striped with aqueous solution of various acids and then determined by spectrophotometric method. Mutual separation scheme for ruthenium(III), iridium(III) and osmium(VIII) has been developed. Ruthenium(III) has been separated from commonly associated elements. Different parameter are studied viz effect of acid concentration, reagent concentration, striping agent, flow rate, foreign ion and synthetic mixture corresponding to alloys. Validity of method has been verified by separation of ruthenium(III) from fissium alloy.     

Poly 4-(3-chloropropyl)styrene: Syntheses of monomer,polymerization, characterizations,and thermal degradation of polymer

4-(3-Chloropropyl)styrene, a new functionalized styrene, has been synthesized in three steps from 3-chloropropylbenzene or in two steps from 4-chlorostyrene, and the polymerization has been carried out in bulk, with azobisisobutyronitrile as an initiator. The polymer has been characterized by its molecular weights, glass transition temperature, and NMR spectra. Thermal degradation has also been studied and volatile fractions characterized by GC-MS. A mechanism of depolymerization, very similar to those of various polystyrenes, can be proposed.     

Contactless Conductivity Detection in Capillary Electrophoresis: A Review

The popularity of contactless conductivity detection in capillary electrophoresis has been growing steadily over the last few years. Improvements have been made in the design of the detector in order to facilitate its handling, to allow easy incorporation into available instruments or to achieve higher sensitivity. The understanding of its fundamental working principles has been advanced and the detection approach has also been transferred to lab‐on‐chip devices. The range of applications has been extended greatly from the initial work on small inorganic ions to include organic species and biomolecules. Concurrent determination of cations and anions by dual injection from opposite ends has been demonstrated as well as sample introduction by using flow‐injection systems for easy automation of the process.     

Action of trypsin on a nucleoprotein from sturgeon gonads

A nucleoprotein has been isolated from the gonads of the Caspian sturgeon and its composition has been determined. It has been shown that it contains 55% of DNA, 2% of RNA, 36% of protamines, and about 7% of nonprotamine proteins of nonbasic nature. The nucleoprotein has been hydrolyzed with trypsin, and the amino acid compositions of some hydrolysis products have been studied. On the basis of the results obtained, the hypothesis has been put forward of a possible linkage of the DNA with the basic proteins. It has been shown that protamines react with the DNA through the basic amino acid residues located at various regions of their molecules.M. V. Lomonosov Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 549–553, July–August, 1979.     

Naphthaquinones—II Derivatives of naphthalene-2,7-diol

The oxidation of 1,6-dibromo-2,7-dimethoxynaphthalene has been reinvestigated and the 1-bromodimethoxy-compound has yielded a new bromonaphthaquinone. A transbromination of 1,6-dibromonaphthalene-2,7-diol has been noticed, whilst an azo-dye from this dibromodiol is shown to have a structure different from that expected from the earlier literature.     

Polysaccharides of the protein-lipoid-polysaccharide complex of the mycelium ofVerticillium dahliae. I. Isolation and fractionation

A phytotoxic PLPC has been isolated from the mycelium of the fungusVerticillium dahliae Kleb., strain 614. The polysaccharide component has been split out from the PLPC by mild acid hydrolysis. The polysaccharide has been fractionated and the monosaccharide compositions of the fractions have been determined. A phytotoxic polysaccharide homogeneous according to gel chromatography and chromatography on DEAE-cellulose has been isolated which consists of an α-glucan containing a minor amount of D-glucosamine.     

Multidione, a novel diterpenoid from Jatropha multifida

A novel diterpenoid, multidione, has been isolated from the stems of Jatropha multifida and its structure has been settled from 1D and 2D NMR spectra. The compound possesses a phenolic moiety and a long side chain, structurally similar to the B ring of other lathyrane-diterpenoids in seco-form.The compound has possibly been derived biogenetically from a related lathyrane-diterpenoid.