bluuebunny/crossref_metadata_2025 huggingface dataset:
Sur Quelques Composés Hétérocycliques Renfermant du Fluor
Authors: Buu‐Hoï Ng. Ph. , Hoán Ng. , Jacquignon Pierre
Published: September 2010

Dans ce travail, on décrit la synthèse et les propriétés d'une série de composés dérivés de fluorobenzène. Ce sont principalement des substances hétérocycliques azotées préparées à partir de 4‐acylfluorobenzènes (acides cinchoniniques, quinoléines, indoles, pyrrocolines, pyrimidazoles) et destinées à des études biologiques diverses, notamment à la recherche de propriétes cancérigènes ou d'une action nocive éventuelles sur le tissu hépatique.
La Diffusion Moléculaire de la Lumière par les Solutions de Glycogène et de Dextrine
Authors: Putzeys P. , Verhoeven L.
Published: September 2010

The apparent molecular weights of muscle and liver glycogen of the rabbit, prepared according to Meyer and Jeanloz, as measured by light‐scattering, are independent of the glycogen concentration and the ionic strength. These glycogens behave as if they were ideal non‐electrolytes. The behaviour of a commercial sample of glycogen is quite different: The apparent molecular weight depends strongly on the glycogen concentration. Electrolytes up to an ionic strength of 0.01 increase the light‐scattering. The extrapolated molecular weight is decidedly smaller than for our own preparations. This suggests that the glycogens described in the literature, which behave in a similar manner, are degraded or impure samples. Dextrines prepared by the action of β‐amylase on amylopectines show the same concentration and electrolyte dependency.
The effect of gases on the sintering of lime
Authors: Clark L. M.
Published: September 2010

The rate of sintering of lime at 1000‐1250° C has been determined by following the decrease in surface area, the latter being measured by the amount of a dyestuff absorbed by the lime from an alcohol‐chloroform mixture. It is found that profound differences in sintering rates are produced by varying the type of atmosphere with which the lime is in contact. The following gases have been examined and are arranged in order of decreasing effectiveness: sulphur dioxide; water vapour (565 mm pressure); CO2: air, oxygen and nitrogen argon. The rates of sintering in argon and in vacuo are not significantly different.
Étude du mécanisme de la polymérisation ionique a l'aide des indicateurs radioactifs
Authors: Landler Yvan
Published: September 2010

Le mécanisme d'amorçage et de terminaison de la polymérisation ionique a été étudié dans les systèmes cationique et anionique, à l'aide des catalyseurs contenant du brome radioactif. Le rapport du nombre de molécules du polymère au nombre de molécule catalyseur fixées a été déterminé.
The structure of the jute fibre Part II. The role of the lignin‐hemicellulose complex and other noncellulosic constituents
Authors: Sen M. K. , Hermans P. H.
Published: September 2010

The work reported in this part of the series bears the character of a preliminary investigation

Part I, M. K. Sen and H. J. Woods, Biochim. et Biophys. Acta 3, 510 (1949); see also Nature 161, 768 (1948).

. It is the result of a cooperative research carried out during a three months stay of the first author in the laboratory of the second. It was planned with the aim of applying some new techniques in collecting additional experimental data in connexion with the problem of jute structure. Mainly the experimental results will be stressed, leaving their utilization for future research. Only some tentative interpretations will be touched upon here and there.

The investigation consists of swelling measurements, staining of cross‐sections and the study of X‐ray diagrams taken with monochromatic radiation.
Mimosine (leucaenine) 5th communication )
Authors: Kleipool R. J. C. , Wibaut J. P.
Published: September 2010

The identity of mimosine from Mimosa pudica and of l‐leucaenine from Leucaena glauca Bentham is proved by means of a mixed melting point and Debije‐Scherrer diagram.

The action of diazomethane on the dihydrochloride of mimosine methyl ester leads to a total degradation of the molecule, by which the pyridine ring is broken. Amongst other things there is produced a compound C4H8O3N2 and 3: 4‐dimethoxy‐pyridine. The same compounds are produced by the action of diazomethane on 3‐methoxy‐4‐pyridone.

Some of the properties of mimosine are in agreement with the assumption of a polar structure, which is comparable with a β‐betaine.
Sedimentation von Makromolekülen und Durchströmung von Gelen
Authors: Signer R. , Egli H.
Published: September 2010

Aus den Sedimentationskonstanten konzentrierter Lösungen von Kettenmolekülen und aus den Darcy‐Konstanten von Gelen, die aus Kettenmolekülen gebaut sind, kann auf den Durchmesser der zylindrischen Teilchen geschlossen werden. Die Durchmesserberechnung beruht auf der experimentellen Bestimmung der Durchlässigkeit von geometrisch ähnlichen, makroskopischen Systemen. Cellulose‐ und Gelatinegele zeigen sehr hohe Dispersität.

Kieselsäuregele sind aus wesentlich gröberen Teilchen als magnified image Ketten aufgebaut.

Die Sedimentationsgeschwindigkeit von Cellulosederivaten, Nucleinsäure und Polystyrol ergeben d‐Werte, die auf isolierte Kettenmoleküle schliessen lassen.

Die Durchströmbarkeit isolierter geknäuelter Kettenmoleküle kann mit der Geldurchströmung und mit der Sedimentation in hohen Konzentrationen in Beziehung gesetzt werden.
The entropy of high polymer solutions. Generalization of formulae
Authors: Staverman A. J.
Published: September 2010

The theory of Huggins is extended so as to include application to molecules containing rings and crosslinks. At the same time the definition of Guggenheim's parameter q is slightly revised in such a way that also back bending of flexible and particularly of branched molecules is accounted for as ring formation.

It is shown that Huggins' and Guggenheim's equations are not applicable to molecules containing rings, as they lead to inconsistencies when q differs from its maximum value for a ring‐free molecule. The inconsistency is removed by an improved calculation of the number of configurations of the molecules on the lattice. The number of factors accounting for the fact that a newly placed submolecule is known to be a neighbour of an already placed submolecule is increased. Instead of taking this number equal to the number of submolecules to be placed, viz. r‐1, it must be taken equal to the number of neighbours already placed, viz. 1/2 z(r ‐ q).

In this way an equation is obtained which is applicable to molecules of any degree of ring formation or back bending, and which can be easily generalized to mixtures of any kind of molecules.

The formula for the entropy of the solvent derived from this theory contains two parameters even in the athermal case. From a qualitative consideration of these parameters it is seen that flexibility and particularly branching will reduce the deviations from Raoult's law markedly, and thus the ununderstandable insensitivity of the older formulae with respect to these structural factors is removed.
Crystal violet, an electronic model substance for rubber and related olefins
Authors: van Veersen G. J.
Published: September 2010

It is shown that triphenylmethyl dyes like crystal violet can be used as model substances for rubber and related olefins. Arguments are given in support of the assumption that agents which react with rubber and related olefins in a polar manner, cause a reversible shift in colour from blue to yellow with crystal violet, whereas a fading of the blue colour of crystal violet (if alkaline or reducing agents are excluded) points to a radical reaction. Since the electronic structures of donor olefins and crystal violet are considered and not the molecular structure as usually is done in the choise of a model substance, these dyes have been named “electronic” model substances. Though crystal violet, as an “electronic” model substance cannot be used for the study of the overall reactions, information can often be obtained concerning the first step in a reaction of rubber with a certain chemical agent by means of a simple test‐tube reaction with crystal violet. It is pointed out that the π‐electron availability at the non‐methylated carbon atom of the double bond in rubber and at the nitrogen atoms in crystal violet is probably of the same order. As an application of crystal violet as an “electronic” model substance for rubber, a polar reaction between sulphur and rubber is suggested as the first step in vulcanization.
Lignin in grass (with special reference to the nitrogen present in the lignin preparations)
Authors: de Man Th. J. , de Heus J. G.
Published: September 2010

Two recently published procedures for the determination of lignin in plant material are compared, using samples of Lolium perenne, and figures for the lignin content in relation to the age of this grass are given.

After determining the tyrosine‐ and tryptophane‐ contents of a number of lignin preparations, arguments are put forward to prove that the N‐containing material in these preparations is protein of the same amino acid composition as the true protein of Lolium perenne.
Note on the toxicity and the chemotherapeutic effectiveness of vitamin c derivative of bis (4‐aminophenyl)‐sulfone in guinea pigs infected with tuberculosis
Authors: Sah Peter P. T.
Published: September 2010

Vitamin C derivative of bis(4‐aminophenyl)‐sulfone was found to be moderately active in suppressing experimental tuberculosis in guinea pigs. The new sulfone drug is well absorbed, evenly distributed in the tissues, of sufficiently long retention in the animal body and does not possess too high toxicity, acute or chronic.
The interaction of phosphorus trichloride and benzaldehyde in presence of acetic anhydride
Authors: Atherton F. R. , Clark V. M. , Todd A. R.
Published: September 2010

The action of halogens on trivalent compounds of phosphorus has been generalised, and a new interpretation of the formation of α‐hydroxyphosphonic acids (RCHOH.PO(OH)2) by the action of phosphorus trichloride on carbonyl compounds examined on this basis.
Thermochemical investigations on arylethenes: I. Heats of combustion of phenylethenes
Authors: Coops J. , Hoijtink G. J.
Published: September 2010

The heats of combustions of all the phenylethenes except styrene

Measured by E. J. Prosen, R. Gilmont and F. D. Rossini, J. Research Natl. Bur. Standards 34, 65 (1945); D. E. Roberts, W. W. Walton and R. I. Jessup, idem 38, 627 (1947).

), were measured. The values (UR) given in the table below refer to the isothermisochore reaction: CmHn + (m + 1/4 n) O2 → m CO2(g) + 1/2 n H2O(l) at 30 atm O2 and 25° C.
Urinary excretion of 17‐ketosteroids in normal human subjects under conditions of fatigue
Authors: Dingemanse E. , Veld L. G. Huis In 'T
Published: September 2010

The excretion of 17‐ketosteroids was determined in three normal men before, during and after extremely fatiguing work. The figures reported refer to 8‐hour periods.

It was ascertained that 17‐ketosteroid excretion was increased during fatiguing work.
Some reactions of picolyllithium
Authors: Gilman Henry , Towle J. Lewis
Published: September 2010

Picollyllithium and picolylmagnesium bromide and iodide, unlike their structurally analogous compounds benzylmagnesium chloride and benzyllithium, react with acetyl chloride and wi ethylene oxide in the normal manner.

Some anionic forms which may be involved have been considered.
A simplified method for the calibration of thermoelements
Authors: Meyer G. , Franken J. W.
Published: September 2010

A modification of the usual method of temperature measurement by means of thermoelements is described. The apparatus used has been simplified while the required accuracy has been retained.
Some remarks on the structure of the lithium compounds of α‐picoline and α,α′‐lutidine
Authors: Sixma F. L. J. , de Jong J. I.
Published: September 2010

The distribution of the α‐electrons in the α‐picolyl and in the α,α′ lutidylion is calculated by wave mechanics. On the basis of the results of this calculation some properties of the lithium compounds of α‐picoline and α,α′‐lutidine are discussed.
The Raman spectra of di‐, tri‐ and tetrathionate ions in aqueous solutions
Authors: Gerding H. , Eriks K.
Published: September 2010

Frequency shifts and depolarization factors for the Raman lines of the S2O6“ion in aqueous solution are given. Three p and three dp lines are found. This proves ‐ in agreement with a conclusion drawn already by Duval and Lecomte from other evidence ‐, that the S2O6″ion has the staggered ethane‐like configuration with symmetry D3d. A few calculations for this ion are communicated. The Raman spectra of S3O6″ and S4O6″ in aqueous solution are determined. Incomplete polarization measurements for the Raman lines of the tetrathionate ion are given.
A crit́ical investigation on the viscose filtration process
Authors: Gonsalves V. E.
Published: September 2010

In this article the viscose filtration process is subjected to a further investigation both theoretically and experimentally.

Particularly the method applied in practice at present for the determination of the “clogging constant” of dissolver viscose is criticized.
The raman spectrum of trichloroacrylic acid CCl2  CCl . COOH
Authors: Gerding H. , Haring H. G.
Published: September 2010

The Raman spectrum of liquid trichloroacrylic acid at 80° C is communicated. From this spectrum and from a comparison with the infrared absorption of solid trichloroacrylic acid and a number of salts, it is concluded that an equilibrium between monomeric and (probably) dimeric molecules exists in the liquid. No signs of an appreciable ionization have been found. The Raman spectrum of acrylic acid is briefly discussed.
Thermodynamic properties of mixtures of alkanes differing in chain length. II. Vapour pressures
Authors: van der Waals J. H. , Hermans J. J.
Published: September 2010

A description is given of a micro‐method for the determination of vapour pressures at elevated temperatures. In this method the vapour over the solution is brought into thermodynamic equilibrium with that of the pure volatile component at a lower temperature. The pressure is indirectly determined by the accurate measurement of the difference in temperature between the solution and the pure volatile component.

With this apparatus we have determined the vapour pressure of heptane in mixtures with dotriacontane at 73° C, and in mixtures with a polythene fraction at 109° C. In another apparatus the vapour pressure of 2,2,4‐trimethyl pentane‐hexadecane mixtures has been investigated at 24.9° C. The thermodynamic consequences of the heats of mixing and vapour pressures measured are discussed.
Etudes dans la Sêrie du Thiophène. V. ) Nouvelles cétones thiophéniques et leurs dérivés
Authors: Buu‐Hoï Ng. Ph. , Hoán Ng. , Xuong Ng. D.
Published: September 2010

Dans ce travail, les auteurs décrivent une série de cétones thiophéniques nouvelles, provenant de réactions de Friedel‐Crafts entre d'une part, le thiophène, le 2‐thiotolène, le 2,5‐thioxène, le 2‐chlorothiophène et le 2‐bromothiophène, et d'autre part, des chlorures d'acides aromatiques et d'acides thiophéniques porteurs de substituants variés. Les chlorures d'acides thiophéniques ont été également condensés avec le thioanisole, le thiophénétole, le biphényle, et le fluorène selon Friedel‐Crafts, et avec l'indole et le 2‐méthylindole selon Oddo. En vue d'études biologiques, certaines des cétones ainsi obtenues ont été transformées en α,β,β‐triaryléthénes; les cétones possédant des groupements méthoxyles ont été déméthylées en hydroxycétones, et ces dernières soumises à la réaction de Claisen (allylation puis transposition en orthoallyl‐hydroxycétones). La condensation de plusieurs thiophènes substitués avec les anhydrides phtalique et succinique a été étudiée, et les produits de réaction font l'objet d'études biologiques (effets sur les végétaux).
Investigations on quinones and quinone‐derivatives ). Preparation and antibiotic properties of some substituted p‐benzo‐and p‐toluquinones, hydroquinones and hydroquinone diesters
Authors: Huisman H. O.
Published: September 2010

The preparation of a number of substituted p‐benzo‐ and p‐toluquinones, hydroquinones and hydroquinone di‐esters is described.

The antibiotic properties of these compounds have been tested in vitro against a yeast, various moulds and Gram‐positive and Gram‐negative micro‐organisms.

The toxicity has been determined in white mice by oral administration and by intraperitoneal injection.

The chemotherapeutic activity has been investigated in white mice injected with a lethal dose of pneumococci.
A polarographic determination of vitamin‐K3 (2‐methyl‐1,4‐naphthoquinone) in prepared feeds
Authors: Onrust H. , Wöstmann B.
Published: September 2010

In this article a description is given of a quantitative polarographic method of determining the synthetic vitamin‐K3 (2‐methyl‐1,4‐naphthoquinone).

A non‐aqueous polarographic medium is made up from the petroleum ether extract of the prepared feeds which have been enriched with vitamin‐K3. The concentration of the vitamin‐K3 in this medium, which can dissolve about 8 per cent, by volume of wheat germ oil, can be determined polarographically with the help of an internal standard.

The standard deviation of a determination in a sample with a content of about 80 γ/gram is equal to 2.6 γ, while the quantities of vitamin‐K2 added are in most cases recovered almost completely.
Synthèse de Stérols à chaînes latérales variées (II)
Authors: de Vries Harmen , Backer H. J.
Published: September 2010

D'après le procédé décrit dans le premier mémoire 1) les auteurs ont synthétisé trois nouveaux stérols avec une chaîne latérale renfermant 8, 9 et 12 atomes de carbone. Plusieurs esters de ces stérols donnent des cristaux liquides.
The antitubercular activity of azo dyes. I. Bisazo dyes derived from tetrazotized bis(4‐aminophenyl)‐sulfone and various coupling components
Authors: Sah Peter P. T.
Published: September 2010

In order to find out whether the chemotherapeutic properties of bisazo dyes derived from bis(4‐aminophenyl)‐sulfone are due to the dyes themselves or to the amine tetrazotized (reduction product of the dye), thirty bisazo dyes were prepared by condensing tetrazotized bis(4‐aminophenyl)‐sulfone with various types of coupling components.

Thein vitroactivity of these dyes againstM. Tb.was studied. The most active ones were those derived from 1,3‐diaminobenzene, meta‐aminobenzoic acid, salicylic acid, and 8‐hydroxy‐quinoline. They inhibited the growth of this micro‐organism completely at a concentration of 2 mg per 10 cm3culture. The derivative from meta‐amino‐benzoic acid was still strongly bacteriostatic at a concentration of 0.2 mg per 10 cm3culture.

(3) Nine of the above bisazo dyes representing different types were also tested chemotherapeutically. Only three of them (derivatives from meta‐phenylene diamine, salicylic acid and H acid) were found to be as effective as sulfanilamide inStreptococcus hemolyticusinfected mice. The dye from meta‐phenylene diamine was also as effective as sulfadiazine in mice infected with McGovern, normal Type IPneumococcus. They were ineffective against tetanus toxemia, influenza virus, and rabic virus in mice.

Five of these dyes were tested in vitro against ameba. Two of them (derivatives from 3,5‐diamino‐benzoic acid and 2‐methyl‐1,4‐naphthohydroquinone) were as effective as chloroquine standard. Derivatives from para‐amino‐benzoic acid and phloroglucinol were about one half as active, while the dye from H acid was only amebastatic at dilutions between 1: 500 and 1: 5000.

The relationship between chemical structure and biological activity of these bisazo dyes was discussed.
Decomposition reactions of 4‐nitropyridine
Authors: den Hertog H. J. , Broekman F. W. , Combé W. P.
Published: September 2010

4‐Nitropyridine is converted into a mixture containing salts of N‐(4′‐pyridyl)‐4‐pyridone and 4‐pyridone, when kept at room temperature for some weeks.

The mechanism of this decomposition reaction is discussed.
Derivatives of oxazolidinedione‐2,4: II. The reaction of α‐hydroxy‐esters with isocyanates
Authors: Rekker R. F. , Faber A. C. , Tom D. H. E. , Verleur H. , Nauta W. Th.
Published: September 2010

The reaction between an isocyanate and an α‐hydroxy‐ester leads to the formation of an N‐substituted carbamylo‐α‐hydroxy‐ester, which can give an oxazolidinedione‐2,4 under the influence of a small amount of metallic sodium by ring closure with the splitting off of alcohol.

This ring closure can sometimes be brought about without the use of sodium, by heating the carbamylo‐α‐hydroxy‐ester to a sufficiently high temperature.

Whether or not the required ring closure takes place on heating, depends apparently upon the nature of the carbon substituents of the carbamylo‐α‐hydroxy‐ester, since the latter, on heating to a higher temperature, sometimes can give an isocyanate.
Preparation of 2‐amino‐3‐nitronaphthalene
Authors: van Rij J. H. , Verkade P. E. , Wepster B. M.
Published: September 2010

So far 2‐amino‐3‐nitronaphthalene has not been obtained in a pure state. The preparation of this substance by the partial reduction of 2,3‐dinitronaphthalene with sodium disulphide is described.
Osmotic permeability of cupric ferrocyanide membranes
Authors: Mibashan A.
Published: September 2010

I. The osmotic permeability of a cupric ferrocyanide membrane deposited on porous pyrex was determined at 22° and 33° C for glucose solutions up to 25%, with errors below 2%.

It was found that the so‐called “seasoning” of the cell took place at 33° in two jumps at an osmotic pressure of 33 atm. After seasoning the cell is considerably more permeable to water and the velocity vs. concentration curve displays greater steepness and less curvature.

II. Experiments were carried out with the system glucose solution ‐ semipermeable membrane ‐ aminopyrine solution, and an increase of concentration of 11.7% resp. 23.0% in the latter was obtained.
Migration of halogen atoms in halogenoderivatives of 2,4‐dihydroxypyridine (I)
Authors: den Hertog H. J. , Schogt J. C. M.
Published: September 2010

When 3‐bromo‐2,4‐dihydroxypyridine is chlorinated in aqueous hydrochloric acid solution by adding hydrogen peroxide solution, 5‐bromo‐3‐chloro‐2,4‐dihydroxypyridine is formed. Hence the chlorine atom enters the 3‐position, the bromine atom being removed from this position and reintroduced at the 5‐position.

5‐Bromo‐3‐chloro‐2,4‐dihydroxypyridine was also prepared by brominating 3‐chloro‐2,4‐dihydroxypyridine and chlorinating 5‐bromo‐2,4‐dihydroxypyridine. Its structure was established in different ways, i. e. by converting it into 3‐chloro‐2,4‐dihydroxypyridine on partial reduction, by converting it into 4‐amino‐2,3‐dichloro‐5‐bromopyridine and into 4‐amino‐2,5‐dibromo‐3‐chloropyridine. The structure of the two compounds last mentioned was proved by synthesis.
Compounds related to provitamin D3 (III)): Homocholesterol and the corresponding provitamin (3‐homoprovitamin D3)
Authors: Strating J. , Backer H. J.
Published: September 2010

3‐Homocholesterol (III), obtained by action of LiAlH4 on cholesteryl‐3‐carboxylic methyl ester (II), which has been prepared from cholesteryl chloride by Grignard reaction, has the same steric configuration (β) at carbon atom 3 as cholesterol. Bromination of its acetate (IV) by means of bromosuccinimide, followed by elimination of HBr, leads to the acetate of 3‐homoprovitamin D3 (Vα).

This 3‐homoprovitamin D3 (IX) can be synthesized with a far better yield by introducing first the double bond 7 and then the hydroxymethyl group 3. The magnesium derivative of 7‐dehydrocholesteryl chloride is transformed by CO2 into the carboxylic acid (VII), which is readily methylated with diazomethane. Finally the 7‐dehydrocholesteryl‐3‐carboxylic methyl ester (VIII) is reduced with LiAlH4 to 3‐homoprovitamin D3 (IX).

It is pointed out that the ultraviolet absorption characteristic for the conjugated system of double bonds 5‐7 is subjected to an influence of molecular size.
Viscosity of binary liquid mixtures
Authors: Balázs N. L.
Published: September 2010

An approximate theoretical deduction is given for the viscosity coefficient of binary liquid mixtures combining a modified theory of Eyring for viscous flow with the statistical model due to Guggenheim for strictly regular solutions, using the Bragg‐Williams approximation.
The synthesis and pyrolysis of radio‐active ethyl formate (HC14OOC2H5)
Authors: van den Bos B. G. , Aten A. H. W.
Published: September 2010

The synthesis is described of radioactive ethyl formate, labeled with C14 in the formate group. The pyrolysis of this compound yields radioactive carbon dioxide and inactive ethylene. This indicates that the decomposition is brought about by a simple splitting of the molecule.
Reactivity of 4‐nitropyridine‐N‐oxide: Preparation of 4‐substituted derivatives of pyridine‐N‐oxide and pyridine
Authors: den Hertog H. J. , Combé W. P.
Published: September 2010

It is shown that the nitro‐group in 4‐nitropyridine‐N‐oxide can be readily replaced by negative ions and that the N‐oxides thus obtained, can be reduced quantitatively to the corresponding pyridine derivatives.

This fact reveals an excellent method for the preparation of several 4‐substituted pyridine‐N‐oxides and pyridines. It is all the more useful, since the synthesis of 4‐nitropyridine‐N‐oxide has been simplified.

The preparation of 4‐bromo‐, 4‐chloro‐ and 4‐ethoxypyridine‐N‐oxide is described in detail.
Trichloracétamidines substitués
Authors: Backer H. J. , Wanmaker W. L.
Published: September 2010

En faisant réagir des amines aliphatiques et aromatiques sur le trichloracétonitrile, les auteurs ont préparé plusieurs trichloracétamidines. L'addition de guanidines et d'amidines à ce nitrile conduit à des dérivés moins simples de la trichloracétamidine.

Trois nouveaux composés, soumis à l'examen bactériologique, ont présenté une activité bactériostatique. Cependant leur activité est inférieure à celle du sulfanilamide et leur toxicité en exclue l'application.
Quelques acides ptéroylglutamiques (foliques) substitués dans le noyau benzénique
Authors: Backer H. J. , Houtman A. C.
Published: September 2010

Le mémoire décrit la préparation et les propriétés de six dérivés de l'acide ptéroylglutamique (folique) avec un substituant dans le noyau de l'acide p‐aminobenzoïque. Un de ces acides peut remplacer l'acide ptéroylglutamique comme facteur de croissance pour “Streptococcus faecalis R.”. Parmi les autres dérivés il y a trois acides doués de propriétés bactériostatiques. L'un d'eux est un antagoniste compétiteur puissant.
Cis‐ and trans‐dichloroethene
Authors: Johnsen S. E. J. , Fitzpatrick J. W.
Published: September 2010

Broers, Ketelaar and van Velden (Rec. trav. chim. 69, 1122 (1950)) have reported values for the melting points and heats of fusion of cis‐ and trans‐dichloroethene. They compare their best values with those reported by Timmermans (Bull. soc. chim. Belg. 27, 337 (1913)), and Chavanne (Ibid. 26, 287 (1912)).
Volumetric amino‐nitrogen determinations in glycine and glycyl‐peptides
Authors: Sluyterman L. A. Æ. , Kooistra M.
Published: September 2010

By addition of mercuric chloride to the reaction‐mixture in the Van Slyke apparatus, practically the theoretical values for the amino‐nitrogen content of glycine and peptides having a terminal glycyl‐rest are obtained. If a considerable amount of lithium bromide is present at the same time, the effect of mercuric chloride is greatly lost. Using potassium iodide in that case the right value is found for glycine, but the values for diglycine and triglycine are 7% and 5% too high.
Partially hydrogenated naphthoic acids and α‐alkyl‐phenylacetic acids: Researches on plant growth regulators XIX. Structure/activity IV
Authors: Veldstra H. , van de Westeringh C.
Published: September 2010

(dl) 1,2,3,4‐Tetrahydro‐α‐naphthoic acid, selected for investigation on account of the fact that we deemed it to meet especially well the spatial requirements for active compounds, proved to be very active in the pea‐test, After resolution of the racemate (with (−)menthylamine) it appeared that its activity for the greater part is due to that of the (−)acid (activity comparable with that of α‐naphthylacetic acid), the (+)acid being weakly active only.

(dl)8‐Methyl‐1,2,3,4‐tetrahydro‐α‐naphthoic acid shows the same activity as the unsubstituted acid. 1,2,3,4‐Tetrahydro‐β‐naphthoic acid and its 8‐methyl‐derivative are inactive. A possible explanation for this inactivity is discussed.

As “open” forms of these partially hydrogenated naphthoic acids a number of (dl)α‐alkyl‐phenylacetic acids was investigated, of which (dl)allyl‐phenylacetic acid proved to be the most active one. The resolution of this acid was carried out by means of (+) and (−)α‐phenyl‐ethylamine. Here the (−)acid is practically inactive, the whole of the activity being due to the (+)acid).

There are indications that the active (−) 1,2,3,4‐tetrahydro‐α‐naphthoic acid and (+) allyl‐phenylacetic acid belong to the same steric series.
Symbiosis of tryptophan‐deficient mutants of E. coli B
Authors: Winkler K. C. , van Doorn A. W. J. , Royers A. F. M.
Published: September 2010

In his laboratory Bungenberg de Jong taught us the properties of complex‐systems of all kinds of bio‐colloids. In all this teaching “nucleic acid‐complexes” was his best subject, because here he set us many examples using his own genes as illustrations. Expressed in his many good qualities as an ingenious scientist and as a genial and generous man, these genes were the best possible illustrative material a student can ever have.

The way Bungenberg de Jong affected his collaborators raises the question whether genetic transformations are possible only in pneumococci, I at least carry with me something for life!

From artificial complex coacervates, crossing the borderland between colloid chemistry and biology — Bungenberg de Jong's own kingdom — I turned to the natural complex systems we call bacteria. May the following humble and unimportant note express in some way my admiration and love for the master who guided my steps and polarized my brain.
Orientation in cellulose fibers as derived from measurements of dichroism of dyed fibers
Authors: Hermans P. H. , Heikens D.
Published: September 2010

From accurate measurements of dichroism on dyed model filaments by photoelectric and visual methods a measure for the overall orientation of the dyestuff molecules in the fiber is derived and compared to the overall onentation of the fiber substance as derived from X‐ray and optical measurements. The results are discussed in connection with similar measurements on rayon fibers.
Différents Équilibres de Phases dans Les Solutions D'acétate de Cellulose
Authors: Dervichian D. G. , Magnant C.
Published: September 2010

Le systèm diacétate de cellulose + chloroforme + alcool a été étudié, du point de vue de l'equilibre des phases, dans toute l'étendue des concentrations possibles de chacun des trois constituants. En plus d'un second domaine de coacervation, on a pu ainsi mettre en évidence des phases isotropes et anisotropes et établir le diagramme général du systéme. Ce diagramme de phases rappelle par certains cǒtés ceux des systèmes contenant des électrolytes colloidaux en solutions aqueuses.
Influence of electric charge and valence of ions on the specific precipitation of diphtheria toxin with antitoxic horse serum)
Authors: Dekker W. A. L. , v. d. Meer C.
Published: September 2010

The striking similarity of phenomena found in specific precipitation with those encountered in complex colloid flocculation (in the sense of Bungenberg de Jong et al.) affords reason to expect a similarity of reaction mechanism. By studying the influence of neutral salts on the flocculation of diphtheria toxin with antitoxic horse serum we have tried to answer the question whether electrostatic attraction is as essential for specific precipitation as it is for complex colloid flocculation.
Demonstration of a mesomeric effect of the methylsulfonyl group. (Preliminary communication)
Authors: Kotch A. , Krol L. H. , Verkade P. E. , Wepster B. M.
Published: September 2010

It has been proved that the methylsulfonyl group can exert a (negative) mesomeric effect.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. III. Ultraviolet spectra
Authors: Bergmann Ernst D. , Hirshberg Y. , Pinchas S. , Zimkin E.
Published: September 2010

For a number of products of the condensation between ethanolamine or 2‐amino‐3‐methyl‐butanol‐3 and aromatic aldehydes and ketones. the ultraviolet spectrum has been measured. The observations have been used to distinguish between oxazolidine and Schiff's base structures of the condensation products.

The agreement between the results and the conclusions derived from measurements of the molecular refraction and the infrared spectrum, is satisfactory.

For a number of simple model substances, too, the ultraviolet spectra have been measured, in order to determine the characteristics of the CN‐spectrum.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. V. The dipole moments of 1,3‐dihetero‐substituted 5‐membered ring systems and some related problems
Authors: Bergmann Ernst D. , Fischer Ernst , Zimkin E. , Pinchas S.
Published: September 2010

The dipole moments have been determined for eleven 1,3‐dioxolanes, four oxazolidines and two isomeric Schiff's bases, and four imidazolidines. The influence of the molecular structure of the substances on these moments has been discussed. Certain anomalies appear consistently in the physical constants of the heterocyclic compounds, when they are derived from cyclopentanone, methylisobutylketone or diisobutylketone. In order to obtain a better insight into these anomalies, seven more 1,3‐dioxolanes have been synthesized and their molecular refraction and infrared spectrum studied. Furthermore, the condensation of three ketones with ethanolamine and 3‐methyl‐2‐amino‐butanol‐3 has been investigated, and the molecular refraction and infrared absorption of the products determined and evaluated.
The behaviour of membranes between electrolyte solutions. II. Membrane potentials at oxidized cellophane
Authors: Hirsch P.
Published: September 2010

In order to test the inference arrived at in Part I that the membrane potential at cellulose membranes depends on the dissociation of acid groups in the membrane substance, experiments were carried out with cellophane membranes, in the cellulose of which carboxyl groups had been produced by oxidation. The membrane potential thus raised and that at the original cellophane depend on the pH in a like manner. This is apparent from the shape and position of the Δ.pH‐curves. In this case Δ is no longer the same for KCl and NaCl.
L'action D'hydrazine sur Quelques Sulfonyl‐Cétones; Réduction Selon Wolff Kishner Sans Catalyseur. (Propriétés du groupe sulfonyle XXIV)
Authors: Kloosterziel H. , Backer H. J.
Published: September 2010

L'observation que le groupe carbonyle de la “sulfobenzophénone” (I) est réduit par chauffage avec l'hydrazine nous a amenés à étudier le comportement de quelques autres sulfonylcétones, spécialement de celles où le groupe sulfonyle, soit par proximité soit par vinylogie, peut influer sur le groupe carbonyle.

Le thionaphténone‐3‐1‐dioxyde (III) et la p‐méthylsulfonylacétophénone (V) sont réduits par l'intermédiaire de leurs hydrazones. La p‐tolylsulfonylacétone (XI) donne une hydrazone qui n'est pas réduite par chauffage avec l'hydrazine.

Les sulfonylcetones suivantes sont scindées:

p‐méthylsulfonyl‐α‐(p‐tolylsulfonyl)‐acétophénone (VII)

β‐(p‐tolylsulfonyl)‐acrylophénone (X)

benzylsulfonyl‐acétone (XII).

Enfin l'hydrazone de la 1,3‐bis‐p‐tolylsulfonyl‐acétone (XIII) montre un comportement remarquable que l'on peut expliquer en admettant qu'il se forme, par “hydrazinolyse”, une hydrazide‐hydrazone qui subit la scission de la réaction Wolff Kishner.
Sodium salts of pectin and of carboxy methyl cellulose in aqueous sodium chloride. I. Viscosities
Authors: Pals D. T. F. , Hermans J. J.
Published: September 2010

The extrapolation of the ηsp/c versus c curves for polyelectrolytes in dilute salt solutions is difficult because these curves show a sharp maximum at a polymer concentration, c, where the equivalent concentration of the polyelectrolyte is of the same order of magnitude as that of the extraneous salt. A more reliable figure for the intrinsic viscosity can be obtained if the effective ionic strength is kept constant or nearly constant, in which case ηsp/c versus c becomes a straight line. The slope of this line is discussed in § 8.

The intrinsic viscosities discussed are those of a pectinate and three samples of sodium carboxy methyl cellulose (Na—CMC) in aqueous solutions of sodium chloride. The experimental results can be described satisfactorily by the theory of Hermans and Overbeek. The only unknown parameter is the average square of the distance between the ends of the uncharged molecule, and its value compares well with that known for other cellulose derivatives.

At the limit of zero ionic strength the molecules are practically fully stretched. The application of Simha's formula for ellipsoidal particles leads to reasonable values for the molecular length.

In connection with the high precision aimed at, a study was made of the effect of surface tension in viscometry. This is described in § 4, and leads to the conclusion that for our purpose an Ubbelohde viscometer has preference above an Ostwald viscometer. It was found, further, that the intrinsic viscosity of the polyelectrolytes investigated is a function of the shear‐rate. This phenomenon will be more fully discussed elsewhere.
An improved method for the determination of 2,4 d acid (2,4‐dichlorophenoxy acetic acid) and of M.C.P.A. (2‐methyl‐4‐chlorophenoxy acetic acid) in herbicidal formulations
Authors: Ketelaar J. A. A. , Gersmann H. R.
Published: September 2010

A revised method is given for the determination of 2,4 D acid (2,4‐dichlorophenoxy acetic acid) and M.C.P.A. (2‐methyl‐4‐chlorophenoxy acetic acid) in herbicidal formulations (total phenoxy acetic acids). The preliminary removal of free phenols and cresols is not necessary if methyl red and phenol red respectively are chosen as indicators.

The dissociation constants were determined of some chlorophenols and ‐cresols of the corresponding phenoxy acetic acids (table I).
Cryoscopic and spectroscopic studies of mixtures of HNO3 and BF3
Authors: Gerding H. , Heertjes P. M. , Revallier L. J. , Steeman J. W. M.
Published: September 2010

A cryoscopic study of mixtures of HNO3 and BF3 reveals the existence of a compound HNO3. 2BF3 (melting point 53° C). Mixtures of composition HNO3. 1/2BF3, HNO3. BF3, HNO3. 2BF3 and HNO3. 1/2SO3 were studied spectroscopically. In liquid HNO3. 1/2BF3 and HNO3. BF3 the reaction HNO3 + BF3 → NO+2 + BF3OH‐ takes place to a more or less considerable extent. In HNO3. 2BF3 no clear indication for the presence of NO2+ ions is found. HNO3. 2BF3 probably is an addition compound comparable with those described by Baumgarten c.s. for BF3 with a number of sulphates or pyrophosphates.

In liquid HNO3. 1/2SO3 a considerable amount of NO2+ and HSO4 ions are present.
The reaction of urea with formaldehyde
Authors: de Jong J. I. , de Jonge J.
Published: September 2010

The reaction of urea and formaldehyde, giving monomethylolurea, is reversible in a neutral, acid or alkaline aqueous solution, the forward reaction being bimolecular and the reverse reaction monomolecular.

The forward and reverse reactions are catalyzed to the same extent by hydrogen ions as well as by hydroxyl ions. The specific rates are directly proportional to the hydrogen and hydroxyl ion concentrations. There appears to be an influence of the buffer concentration on the reaction rates probably due to a general acid and general base catalysis.

The equilibrium is almost independent of the pH of the solution and of the buffer concentrations.

The activation energies of the forward and the reverse reaction have been determined, giving the heat of reaction. Within experimental error these activation energies may be the same for the non‐catalyzed and for the catalyzed system.

The reaction mechanism is discussed.
Separation of small amounts of thorium from the cerite earths of monazite and other elements. Use of cinnamic acid
Authors: Krishnamurty K. V. S. , Venkateswarlu Ch.
Published: September 2010

Cinnamic acid has been found to be a suitable reagent for the estimation and separation of small amounts of thorium from the cerite earths of monazite. The latter in concentration upto 2000 fold may be conveniently separated in a single precipitation. Using this reagent a separation from other common elements may also be effected. The presence of a little nitric acid (about N/100) in the wash liquid is found useful in giving separations described particularly when dealing with relatively large amounts of the cerite earths.
Amides IX: Acylation of amides and amines
Authors: Dunn P. , Parkes E. A. , Polya J. B.
Published: September 2010

Further proofs are adduced in favour of the theory of add catalyzed acylation of amides to diacylamines. Synthetic examples are given partly as improvements of older methods, partly as illustrations of the theory. The preparation of the following new compounds is described: N‐isobutyrylbenzamide, N‐acetyl‐n‐butyramide, N‐methyldipropionimide and N‐methyldi‐n‐butyrimide.
On the heat of electrolytic dissociation of acetic acid and of the first h‐ion of citric acid in an aqueous solution
Authors: Snethlage H. C. S.
Published: September 2010

The heat of solution of citric and of acetic acid is calculated for various concentrations from the calorimetric experiments of Richards and his coworkers. From these data the heat of electrolytic dissociation of the two acids is calculated. By extrapolation, the heat effect at infinite dilution is evaluated. It is pointed out that for both acids the value of this last heat effect is in good agreement with the value which was obtained by Bates and Pinching for citric acid and by Harned and Ehlers for acetic acid from experiments on the change of the E.M.F. of suitable cells by temperature. Calculation of the heat of dilution from the heat of electrolytic dissociation at infinite dilution is possible at sufficiently low concentrations.
Contribution to the knowledge of metanethole III
Authors: van der Zanden J. M. , de Vries G.
Published: September 2010

We confirmed the structure of an oxidation product of metanethole with m.p. 180–180.5°, obtained by us on an earlier occasion

I and II in Rec. trav. chim. 68, 261‐274 and 407‐418 (1949).

), by means of a synthesis.

We synthesized metanethole in two different ways, and the stereoisomer, m.p. 99°, for which we had already found two methods of preparation, in a third way. In the light of the results obtained, we discussed the position of the H atoms in the 5‐membered ring of these products.

For the metanethole oxidation product, m.p. 115–116°, we suggested a new structure as a possibility.
On the synthesis of ascorbic acids
Authors: Stedehouder P. L.
Published: September 2010

The preparation of ascorbic acids from derivatives of aldoses and esters of hydroxy‐alkoxy‐acetic acid, is described

Dutch patent no. 59,711 of July 15th 1947. This investigation was carried out in 1942.

.

l‐Ascorbic acid (Vitamin C) has been obtained from tetra‐acetyl‐l‐xylonic acid nitrile (tetra‐acetyl‐l‐threose‐cyanohydrin) and hydroxy‐ethoxy‐acetic acid ethyl ester. The latter compound is stable and easily accessible; a simplified method of preparation has been worked out for tetra‐acetyl‐l‐xylonic acid nitrile.

d‐Ascorbic acid, l‐arabo‐acetic acid, and d‐gluco‐ascorbic acid have been prepared similarly.
The preparation of alkylthio substituted naphthoquinones‐1,4 and benzoquinones‐1,4
Authors: Tjepkema J. J.
Published: September 2010

The preparation of a number of 2,3‐dialkyl(aryl)thio‐naphthoquinones‐1,4 and 2,3,5,6‐tetraalkyl(aryl)thio‐naphthoquinones‐l,4 is described.
Polymerization of methylchavicol: Dimerization coupled with hydration II
Authors: van der Zanden J. M. , de Vries G.
Published: September 2010

magnified image

In the preparation of II, just as in the earlier dimerization coupled with hydration of methylchavicol, , the two inactive stereoisomers were obtained. By reduction of the alcohol function they yielded, in accordance with the nature of the isomerism in question, the same final product.
Investigations on sterols. V. Thio‐derivatives of provitamins D
Authors: Buisman J. A. Keverling , Westerhof P.
Published: September 2010

A description is given of the synthesis of the thio‐analogues of ergosterol and 7‐dehydrocholesterol from these two compounds.
Synthesis of potential chemotherapeutics in bile duct infections. I
Authors: van Kampen E. J.
Published: September 2010

The preparation of a chemotherapeutic for combating infections of the bile ducts is described.

By coupling of 3′,3″‐diaminophenolphthalein withp‐acetylaminobenzene sulphochloride we obtained 3′,3″‐di‐acetylsulphanilylamidophenolphthalein, which by saponification was transformed into 3′,3″‐di‐sulphanilylamidophenolphthalein. This product was found, both by bacteriological and pharmacological investigation, to possess desirable chemotherapeutic properties.
A simple theory of electrophoresis: Determination of the equivalent weight of colloid electrolytes
Authors: de Wael J. , Wegelin E.
Published: September 2010

A simple theory of electrophoresis has been given, starting from Kohlrausch's regulating function. Stress is laid on the correct method of calculating the mobility from the velocities of rising and descending boundaries. It appears to be possible to calculate the equivalent weight of colloid electrolytes from a Tiselius diagram
Synthesis of linear oligomers of ε‐amino. Caproic acid: Synthesis of a tri‐, tetra‐ and penta‐ω‐peptide
Authors: van der Want G. M. , Peters H. , Inklaar P.
Published: September 2010

The syntheses of three linear condensation products of ε‐aminocaproic acid of a low degree of condensation, H[NH(CH2)5CO]xOH x = 3, 4 and 5, are described. The purification of these compounds has been accomplished by means of chromatographic adsorption.
The rate of hydrolysis of some p‐nitrophenol esters of ortho‐phosphoric‐ and thio‐phosphoric acid
Authors: Ketelaar J. A. A. , Gersmann H. R. , Koopmans K.
Published: September 2010

The rate of alkaline hydrolysis of some p‐nitrophenyl esters of ortho phosphoric and thiophosphoric acid has been investigated at different temperatures. The energies of activation have been computed. All results can be read from table II.
The action of bromine on derivatives of urea in neutral aqueous solution
Authors: de Jong J. I. , de Jonge J.
Published: September 2010

It was found that only unsubstituted amide groups in derivatives of urea are rapidly attacked by bromine in neutral solution while the reaction with alkylated amide groups is very slow.

Dimethylol urea has a symmetrical structure.
On the tuberculostatic activity of the thiazole carboxylic acid hydrazides
Authors: Beyerman H. C. , Bontekoe J. S.
Published: September 2010

The high anti‐tuberculosis activity of pyridine‐4‐carboxylic acid hydrazide (isonicotinic acid hydrazide, INH), together with the chemical similarity of pyridine and thiazole, has induced us to synthesize the thiazole carboxylic acid hydrazides and to investigate their possible effects upon Mycobact. tuberculosis.

The chemical structure/biological activity relationship is extensively discussed.

In agreement with the hypothesis, thiazole‐2‐carboxylic acid hydrazide in in vitro and in in vivo tests proved to be of equal tuberculostatic activity to pyridine‐2‐carboxylic acid hydrazide (picolinic acid hydrazide); they almost completely inhibited the development of experimental tuberculosis in mice.
Synthesis and reactivity of 5‐chloro‐2,4‐dihydroxypyridine
Authors: Kolder C. R. , den Hertog H. J.
Published: September 2010

A synthesis of the 5‐chloro‐derivative of 2,4‐dihydroxypyridine is described. In addition to this compound, 5‐chloro‐2‐ethoxy‐4‐hydroxypyridine, 5‐chloro‐4‐ethoxy‐2‐hydroxypyridine, and 5‐chloro‐2,4‐diethoxypyridine were prepared.

The reactivity of 5‐chloro‐2,4‐dihydroxypyridine towards bromine and aqueous solutions of hydrobromic and hydrochloric acid has been examined.