Interpreting magic-number and evaporation effects in cluster size distributions

The Smoluchowski equations describe the coalescence of clusters to form larger clusters. If the kernels or rate constants in these equations are homogeneous, meaning thatK _{j, k} = ² K _jk (wherej andk are cluster sizes), it can be shown that the populationsn _k approachAk ^a e - ^bk for largek and large time, where the constantsa andb depend on the homogeneity parameter. Deviations of observed populations from this formula may be ascribed to magic-number and/or evaporation effects on the kernels. By integrating the Smoluchowski equations numerically for various choices of the kernels, we derive population distributions and show the effects of magic-number clusters and evaporation on the population distribution. Various methods are used to extract the value of, in order to determine the best way to extract the underlying value of from experimental data. Experimental populations for sodium metal clusters are then analyzed according to the same procedure, to extract the homogeneity parameter and explain the patterns in the population distribution.     

VOLATILE COMPOUNDS FROM Haplophyllum myrtifolium

The volatile fractions of the petroleum ether extract and of the alkaloid extract ofHaplophyllum myrtifoliumBoiss., endemic to Turkey, were trapped by using the Solid Phase Micro Extraction (SPME) technique and analyzed by GC/MS. Forty-seven compounds were characterized from the petroleum ether extract of the aerial parts with -caryophyllene (14.6 %), decane (11.4 %), and -phellandrene (7.0 %) as the major components. Chavibetol (21.9 %), eugenol (19.1 %), methyleugenol (10.8 %), trans-linalool oxide (7.1 %) and -cyclocitral (6.0 %) were identified as the major components among the forty-two compounds characterized in the chloroform eluate of the alkaloid extract.     

Phenolic Components of Empetrum nigrum Extract and the Crystal Structure of One of Them

Four phenolic components are isolated from the CHCl ₃ extract ofEmpetrum nigrumL. Three of them are known from this plant. The fourth (6,8-dimethylpinocembrine) is isolated from crowberry for the first time. The previously proposed structure for 2'-methoxy-4'-hydroxy- ,-dihydrochalcone is confirmed by x-ray structure analysis     

Photometric determination of iodine in iodated salt using diphenylcarbazide

A method is described for the colorimetric determination of iodine in iodated salt. It is based on oxidation of DPC reagent by iodate ion in acidic medium. The resultant DPCO is extracted in CCl₄. The absorbance of this extract measured at 486 and 558 nm gave quantitative measure of the iodate-DPC reaction.     

Lipids ofGlycyrrhiza glabra roots

A petroleum ether extract ofGlycyrrhiza glabra L. roots was investigated. The extract contains 70% neutral lipids and 30% polar lipids. Hydrocarbons, sterols esters, triacylglycerols, free fatty acids, free sterols, and diacylglycerols were identified. The fatty acid contents of all of the acyl-containing lipids were determined. Fourteen fatty acids were identified; the 18 2 fatty acid prevails among the unsaturated acids, and the 16 0 acid prevails among the saturated acids.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 367–370, February, 1995.     

A New Isoflavone fromAstragalus peregrinus

In addition to diadzen, genisten, luteolin, apigenin, and apigenin-7-O-neohesperidoside, the methanol extract of the aerial parts ofAstragalus peregrinus yielded a new isoflavone identified as 7-hydroxy-3,5-dimethoxyisoflavone.     

Determination ofβ-Mercaptopyruvic acid in cysteine transamination mixture by titration with o-Hydroxymercuribenzoic acid using dithiofluorescein as an indicator

Summary A rapid and direct thiotitrimetric method for the determination of-mercaptopyruvic acid is described.o-Hydroxymercuribenzoic acid is used as a direct titrant with dithiofluorescein as an indicator. Cysteine and other thiol compounds which have a primary or secondary amino group can be inactivated by formaldehyde to form thiazolidine derivatives.-Mercaptopyruvic acid can be successfully determined to the limit of 0.2mol with an error less than 5% in the presence of-ketoglutarate, glutamate, PLP, as well as cysteine. The procedure described can be employed for the determination of-mercaptopyruvic acid formed during cysteine transamination using a rat liver extract as the enzyme source.

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Zusammenfassung Eine rasche Methode zur direkten thiomaßanalytischen Bestimmung von-Mercapto-Brenztraubensäure wurde beschrieben. o-Hydroxy-mercuribenzoesäure dient als Maßlösung mit Dithiofluorescein als Indikator. Cystein und andere Thiolverbindungen mit einer primären oder sekundären Aminogruppe können mit Formaldehyd zu Thiazolidinderivaten umgesetzt und damit inaktiviert werden.-Mercapto-Brenztraubensäure läßt sich bis zu 0,2Mol in Gegenwart von-Ketoglutarat, Glutamat, Pyridoxalphosphat und Cystein auf 5% genau bestimmen. Das Verfahren eignet sich zur Bestimmung von-Mercaptobrenztraubensäure, die bei der Transaminierung von Cystein mit Hilfe eines Rattenleberextraktes entsteht.

     

Triterpenoids from the leaves of far eastern species of the shrubby birchesBetula ovalifolia andB. middendorfii

From the unsaponifiable fraction of an ethereal extract of the leaves ofBetula ovalifolia have been isolated the new triterpene 20(S),24(R)-epoxydammarane-3,17,25-triol (V) and the corresponding monoketone at C³ (VI). The leaves ofB. middendorfii have yielded the triterpene (IX) and (X), identified as, respectively, dammar-23-ene-3,12,20(S),25-tetraol and damman-25-ene-3,12,20-(S),24-tetraol, which have been obtained previously from the leaves ofBetula platyphylla Sukatchev var.japonica.The species of birch were determined by V. I. Baranov of the Laboratory of Chemotaxonomy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 323–329, May–June, 1981.     

Physalis withanolides II. Withaphysanolide

A new withanolide with the composition C₂₈H₃₈O₇, which has been called withaphysanolide (I) has been obtained from a chloroform extract of an aqueous extract of the epigeal part ofPhysalis viscosa L. On the basis of a study of the UV, IR, PMR, and mass spectra of (I) and the products of the oxidation of its acetate (II) — a lactone C₉H₁₂O₃ (III) and 4-acetoxy-5-hydroxy-1,17-dioxoandrosta-2,8(14)-diene (IV) — the structure of 4,5,17,20-tetrahydroxy-l-oxo-22R-witha-2,8(14),24-trienolide is suggested for (I).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 214–217, March–April, 1980     

Determination of Triandrin and Salicin in Salix viminalis L. by Reversed-Phase High-Performance Liquid Chromatography

The optimal separation of phenolic components of the bark of basket willow Salix viminalis L. was attained using reversed-phase high-performance liquid chromatography with isocratic elution. Triandrin (1-O--D-glucopyranoside of p-coumaryl alcohol) and salicin (1-O--D-glucopyranoside of salicyl alcohol) were identified. Regularities in the retention of triandrin and salicin in the Separon SGX C₁₈–binary mobile phase (acetonitrile–water) system were considered. A procedure was developed for the quantitative determination of triandrin in raw basket-willow bark and its extract.     

离子液体选择性萃取生物产品

Imidazolium based room temperature ionic liquids have been used to extract selectively L-tryptophan from fermentation broth. BF4 anion was found to enhance dramatically the partitioning of L-tryptophan into ionic liquid phase from aqueous solutions.     

Complexation of Scandium upon Its Extraction with Solutions of N-(2-Hydroxy-5-nonylbenzyl)-β,β-dihydroxyethylamine in Octanol

Complexation of scandium upon its extraction with N-(2-hydroxy-5-nonylbenzyl)-,-dihydroxyethylamine in octanol from chloride solutions (ScCl₃ + HCl) at pH 3.90–4.60 was studied. The extractant and scandium extract were investigated using IR spectroscopy. The composition of the extractable complex was determined, and an equation for scandium extraction was suggested.     

Nichtflüchtige Inhaltsstoffe vonArtemisia afra

Summary From the pentane extract of the dried leaves ofArtemisia afra JACQ, an Asteraceae native in Southern Africa, the following non volatile constituents have been isolated: Cerylcerotinate, a wax ester, the hydrocarbon nonacosane and the triterpenes friedelin, - and -amyrin. The relative high content of cerylcerotinate in this plant (0.25%) is noteworthy.

     

Methode zur gleichzeitigen Bestimmung von Pregnandiol und Pregnantriol aus einer Urinprobe

Zusammenfassung Eine chemische Methode zur routinemäßigen Bestimmung von 5-Pregnan-3,20-diol und 5-Pregnan-3,17,20-triol aus einer Urinprobe wird beschrieben. Die Methode besteht aus folgenden Schritten:1. Enzymatische Hydrolyse; 2. Extraktion und Reinigung; 3. Säulen-Chromatographie zur Trennung von Pregnandiol und Pregnantriol; 4. Farbreaktion zur Bestimmung von Pregnantriol; 5. Reinigung der Pregnandiol-Fraktion durch Oxydation mit Kaliumpermanganat und erneute Säulen-Chromatographie; 6. Farbreaktion zur Bestimmung von Pregnandiol. Die Brauchbarkeit der Methode wird aufgrund der Zuverlässigkeitskriterien: Spezifität, Richtigkeit, Genauigkeit, Empfindlichkeit nachgewiesen.

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Method for the simultaneous determination of pregnanediol and pregnanetriol in one urine sample

A chemical method is described for the routine assay of both 5-pregnane-3,20-diol and of 5-pregnane-3,17,20-triol in one urine sample. The method involves the following steps: (1) enzymatic hydrolysis of the urine; (2) extraction of the hydrolysed urine and purification of the extract; (3) column chromatography for the separation of pregnanediol and pregnanetriol; (4) colour reaction for the determination of pregnanetriol; (5) further purification of the pregnanediol fraction by oxidation with potassium permanganate and column chromatography; (6) colour reaction for the determination of pregnanediol. The practicability of the method has been checked by the following criteria of reliability: specificity, accuracy, precision and sensitivity.

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Dissertation, Med. Fakultät, Univ. Bonn 1970     

Kinetics and mechanism of the hydrolysis of sodium carboxymethylcellulose (Na-CMC) by a cellulase complex

TheSomogyi-Nelson colorimetric method is applied in a new manner more suitable for evaluating the kinetics of the enzyme hydrolysis of sodium carboxymethylcellulose (Na-CMC) catalyzed by the cellulase complex. By means of selective inhibition of a chosen enzyme from the cellulase complex it became possible to trace the effect of the other enzymes included in its composition.

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Kinetik und Mechanismus der Hydrolyse von Natriumcarboxymethylcellulose (Na-CMC) durch einen Cellulase-Komplex

Zusammenfassung Die kolorimetrische Methode nachSomogyi undNelson wird nach einem neuen Verfahren zur Verfolgung der Kinetik der hydrolytischen Spaltung von Natriumcarboxymethylcellulose (Na-CMC), katalysiert durch den Cellulase-Komplex, angewandt. Durch selektive Inhibierung eines bestimmten Enzyms des Cellulase-Komplexes kann man die Wirkung der anderen zu seiner gesamten Zusammensetzung gehörenden Enzyme verfolgen.

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Symbols Used E enzyme (E—cellulase;E—exo-cellobiohydrolase;E—-glucosidase) - [E] _w weight concentration of enzymeE - S substrate (Na-CMC—sodium carboxymethylcellulose) - [S]₀ weight concentration of substrateS - I inhibitor (I—lactose;I—calcium chloride;I—condurrite-B-epoxide) - P product (P—oligosaccharides;P—cellobiose;P—D-glucose) - P end product (K , K , K ) - DP degree of polymerization - DS degree of substitution - ES enzyme-substrate complex (E S, E S, E S) - EP enzyme-product complex (E P, E P) - EI enzyme-inhibitor complex (E I, E I, E I) - M _s molecular mass of substrateS - K _s substrate constant (K _s , K _s , K _s ) - K _I inhibitor constant (K _I , K _I , K _I ) - K _m Michaelis-Menten constant - k ₊₁,k ₊₂ (k ₊₂ ,k ₊₂ ,k ₊₂ ) forward rate constants - k _–1 reverse rate constant - ₀ initial rate of reaction - V maximal reaction rate - A change in absorbance - molar absorption coefficient - wavelength Herrn Prof. Dr.Hans Tuppy zum 60. Geburtstag herzlichst gewidmet.     

Relativistic perturbation theory of molecular structure

Summary The recently developed relativistic double perturbation theory is extended to handle relativistic changes of molecular structure more easily. This is achieved by simple coordinate scalings. Accurate higher order mixed perturbation energies for H ₂ ⁺ are calculated. The relativistic changes of bond energy,DE, of bond length,R _e , and especially of force constant,k, and of anharmonicity,a, are large, up to 100%·(Z/c)². The dominant contributions tok anda are due to the indirect change of the nonrelativistick anda connected with the relativistic change of bond length. Accordingly the relativistic changes obey Badger's and Gordy's rules (–RDEk).Dedicated to Prof. Klaus Ruedenberg in appreciation of his fundamental contributions to both formal theory and physical explanations in quantum chemistry     

On the Interaction of Two Finite-Dimensional Quantum Systems

Interaction of quantum system S ^a described by the generalised × eigenvalue equation A| _s =E _s S ^a | _s (s=1,...,) with quantum system S ^b described by the generalised n×n eigenvalue equation B| _i = _i S ^b | _i (i=1,...,n) is considered. With the system S ^a is associated -dimensional space X ^a and with the system S ^b is associated an n-dimensional space X _n ^b that is orthogonal to X ^a . Combined system S is described by the generalised (+n)×(+n) eigenvalue equation [A+B+V]| _k = _k [S ^a +S ^b +P]| _k (k=1,...,n+) where operators V and P represent interaction between those two systems. All operators are Hermitian, while operators S ^a ,S ^b and S=S ^a +S ^b +P are, in addition, positive definite. It is shown that each eigenvalue _{k i} of the combined system is the eigenvalue of the × eigenvalue equation . Operator in this equation is expressed in terms of the eigenvalues _i of the system S ^b and in terms of matrix elements _s |V| _i and _s |P| _i where vectors | _s form a base in X ^a . Eigenstate | _k ^a of this equation is the projection of the eigenstate | _k of the combined system on the space X ^a . Projection | _k ^b of | _k on the space X _n ^b is given by | _k ^b =( _k S ^b –B)^–1(V– _k P})| _k ^a where ( _k S ^b –B)^–1 is inverse of ( _k S ^b –B) in X _n ^b . Hence, if the solution to the system S ^b is known, one can obtain all eigenvalues _{k i} } and all the corresponding eigenstates | _k of the combined system as a solution of the above × eigenvalue equation that refers to the system S ^a alone. Slightly more complicated expressions are obtained for the eigenvalues _{k i} } and the corresponding eigenstates, provided such eigenvalues and eigenstates exist.     

High-Performance Liquid Chromatographic Determination of Cinnarizine in Workplace Air

Summary Cinnarizine is a pharmaceutical drug used in the treatment of cerebral and peripheral vascular diseases. A reversed-phase liquid chromatographic method with fluorescence detection has been developed for determination of the drug in workplace air. Air sampling in the workplace is performed on perchlorovinyl filters (FPP), the filters are extracted with methanol for 40 min, and the extract (50 L) is injected and separated on a 250 mm × 4.6 mm i.d., 5 m particle, C₈ reversed-phase column with 1% ammonium acetate (pH 4.5)–acetonitrile, 1:4 (v/v), as mobile phase at a flow rate of 1 mL min^–1.