Soluble polysaccharides of Rhodotorula flava

Conclusions 1. Xanthalin has been shown to have the structure of 2, 2-dimethyl-3, 4,-diangeloyloxy-3, 4-dihydropyrano-5, 6:6, 7-coumarin on the basis of the preparation of a number of derivatives and cleavage products.2. The following products of the alkaline hydrolysis of xanthalin have been isolated and characterized for the first time: (±)-3, 4-dihydroxy-3, 4-dihydroxanthyletin (isokhellactone), C₁₄H₁₄O₅, with mp 213–215° C and (–)-trans-3-hydroxy-4-methoxy-3, 4-dihydroxanthyletin (isomethylkhellactone, C₁₅H₁₆O₅, with mp 136.5–138° C and [] _D ²⁰ –47.7 (ethanol).Khimiya Prirodnykh Soedinenii, Vol. 6, No. 1, pp. 14–19, 1970     

Spectrophotometric determination of vanadium with 4-(1′H-1′,2′,4′-Triazolyl-3′-azo)-2-methylresorcinol

Summary 4-(1H-1,2,4-Triazolyl-3-azo)-2-methylresorcinol reacts with vanadium(V) at pH 8.10 (Tris-HClO₄ buffer solution) to produce a pink-violet 11 complex ( _max=525 nm,=2.55×10⁴l·mol^–1· cm^–1) in a 50% (v/v) methanol-water medium, which allows the spectrophotometric determination of 0.1 to 1.51 ppm of vanadium. The method has been applied for the determination of the vanadium content in low alloy steels.

---

Spectrophotometriscbe Bestimmung von Vanadin mit 4-(1H-1,2,4-triazo-lyl-3-azo)-2-methylresorcin

Zusammenfassung Vanadin bildet bei pH 8,10 (Tris-HClO₄-buffer) mit 4-(1H-1,2,4-tri-azolyl-3-azo)-2-methylresorcin ein rosenrot-violettes Chelat, dessen Absorptionsmaximum bei 525 nm in Gegenwart von 50% Methylalkohol gemessen wird. Dieser 11-Komplex entspricht bei einer Vanadin-Konzentration von 0,1–1,51g/ml dem Beerschen Gesetz; seine molare Absorptivität ist 2,55×10⁴l·mol^–1·cm^–1. Das Verfahren wurde zur Bestimmung des Vanadins in Stahl verwendet.

     

Reaction of sulphur dioxide with chlorocarbonyls of ruthenium,rhodium and iridium

Summary The reactions of SO₂ with chlorocarbonyls of rhodium and iridium ([M(CO)₂Cl₂]^– and ruthenium ([Ru(CO)_2–Cl₂]_n) ions were studied. Addition of either the Ph₄As⁺ cation or the nitrogen-donor ligands 2,2-bipyridine (bipy),o-phenylenediamine (opd), 1,10-phenanthroline (phen), 2,2,6,2-terpyridine (terpy) or 6,7-dihydro-1,4-di(2-pyridyl)-5H-cyclopenta {d}-pyridazine (5-dppn) to the SO_2– treated chlorocarbonyl solutions resulted in the formation of various complexes according to the nature of metal and ligand. The products have been characterized by physicochemical methods.     

Reactions of pennogenin and related compounds. IV. Formation of (25R,22′R,25′R)-3β,3′β-diacetoxy-26,22′-epoxy-16,16′-bifurosta-5,20(22),5′,17′(20′)-tetraen-26′-ol from pennogenin diacetate under the action of BF3·Et2O

A new direction of the reaction of pennogenin diacetate with BF₃·Et₂O has been discovered in which a previously unknown dimeric steroid is formed — (25R,22R,25R)-3,3-diacetoxy-26,22-epoxy-16,16-bifurosta-5,20(22), 5,17(20)-tetraen-26-ol, the structure of which has been established as the result of an analysis of IR, UV,¹H and¹³C NMR, and mass spectra. A probable mechanism for the formation of the title compound from pennogenin diacetate is suggested.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Institute of Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 202–208, March–April, 1990.     

Synthesis of heterocycles from 1,5-diketones. 3. Alicyclic 1,5-diketones in reaction with phenylhydrazine

8-R-7aH-5,6,7,8,9,10,11,12-Octahydroindolo[3.2.1-d,e]acridines, 1,2,3,4-tetra-hydrocarbazole, 9-R-sym-octahydroacridines, and 9-R,10-phenyl-sym-octahydroacridinium salts are formed by the action of phenyl-hydrazine on alkylidene-2,2-dicyclohexanone or the corresponding 8-R-tricyclo(7.3.1.0^2,7)tridecan-2-ol-13-ones in an acid medium. Postulations were made for the paths of formation of these compounds.2,2-Dimethyl-3-oxa-4a-(2,2-dimethyltetrahydropyran-4-on-5yl-methyl)-4aH-1, 2,3,4-tetrahydrocarbazole, 3,3,14,14-tetramethyl-2-oxa-5a,10b-(methanoxyisobutane)-1,2,3,4,5a,10b,11,11a-octahydroquinindoline, 2,2-dimethyl-3-oxa-1,2,3,4-tetrahydrocarbazole and 3,3,6,6-tetramethyl-2,7-dioxa-sym-octahydroacridine were obtained by the reaction of methylene-3,3-di(6,6-dimethyltetrahydropyran-4-one) with phenylhydrazine in acetic acid. The quinindoline structure was confirmed by the synthesis of this compound from 2,2-dimethyl-3-oxa-4a-(2,2-dimethyl-tetrahydropyran-4-on-5-ylmethyl)-4aH-1,2,3,4-tetrahydrocarbazole by the action of ammonia.For article 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 46–52, January, 1986.     

Spectrophotometric determination of palladium with a new chelating reagent,N,N-dimethyl-N′-(4-methyl-5-nitro-2-thiazolyl) thiourea

Summary N,N-Ditnethyl-N-(4-methyl-5-nitro-2-thiazolyl)thiourea A new spectrophotometric method for the determination of palladium with N,N-dimethyl-N-(4-methyl-5-nitro-2-thiazolyl)thiourea (DMNT) is proposed. DMNT instantly forms a yellow chelate with Pd(II) at pH 2 at room temperature, which is readily extracted into organic solvents such as chloroform and shows a higher absorption maximum (=40,400) at 413 nm. The ratio of Pd(II) to reagent in the chelate is 12 as determined by the widely used method and also verified by synthesis of the authentic Pd-chelate. The chelate conforms well with the Lambert-Beer's law over a wide concentration range (3.3–22g in 10 ml chloroform). The optimum concentration range of palladium for spectrophotometry by the Ringbom plot is 5.6–18.6g in 10 ml of chloroform solution. This method gives a good reproducibility, high sensitivity and high accuracy in the presence of many foreign ions.

---

Spektrophotometrische Bestimmung von Palladium mit N,N-Dimethyl-N- (4-methyl-5-nitro-2-thiazolyl)-thioharnstoff (DMNT)

Zusammenfassung Eine neue spektrophotometrische Methode zur Bestimmung von Palladium mit DMNT wurde vorgeschlagen. Dieses Reagens bildet mit Pd(II) bei pH 2 und Zimmertemperatur ein gelbes Chelat, das mit Chloroform gut extrahierbar ist und bei 413 nm ein hohes Absorptionsmaximum (=40400) zeigt. Dessen Zusammensetzung wurde in üblicher Weise zu 12=Pd: DMNT bestimmt. Im Konzentrationsbereich 3,3–22g/10 ml entspricht das Chelat dem Lambert-Beerschen Gesetz. Die optimale Konzentration für die spektrophotometrische Bestimmung liegt zwischen 5,6 und 18,6g/10 ml Chloroform. Das Verfahren gibt gut reproduzierbare Ergebnisse, ist hoch empfindlich und auch in Anwesenheit vieler Fremdionen sehr genau.

     

Kinetics of the displacement of aqua ligands from cis-diaqua(ethylenediamine)-platinum(II)perchlorate by adenosine 5′-monophosphate in aqueous medium

The kinetics of the interaction of adenosine 5-monophosphate (5-AMP) with cis-[Pt(en)(H₂O)₂]²⁺ have been studied spectrophotometrically as a function of [Pt(en)(H₂O)₂]²⁺, [5-AMP] and temperature at pH 4.0, where the substrate complex exists predominantly as the diaqua species. Both N1 and N7 donor sites of 5-AMP are active for coordination to Pt at this pH. Base stacking and metal-induced macrochelate formation of 5-AMP plays a vital role in determining the concentration limit of 5-AMP during kinetics. Substitution occurs in two consecutive steps; both dependent on the 5-AMP concentration. Activation parameters for both steps have been calculated. The low H ₁ (42.76 ± 1.64 kJ mol^–1) and large negative values of S ₁ (–112.1 ± 5.1 J K^–1 mol^–1) as well as H ₂ (58.1 ± 1.4 kJ mol^–1) and S ₂ (–84.2 ± 4.4 J K^–1 mol^–1) indicate associative modes of activation for both ligand substitution processes in the two consecutive steps.     

The effect of zinc(II) on the formation of 2,2′- and 2,3′-bipyridine complexes of [Ru2II(ttha)]2−(ttha6−=triethylenetetraminehexaacetate)

Ru2II(ttha)(H2O)2]2– (ttha6–= triethylene tetramine hexa-acetate), prepared by the reduction of the ruthenium(III) precursor, reacts with 2,2-bipyridine (2,2-bpy) in a multi-step fashion. The first 2,2-bpy equivalent (1:1) adds with bidentate chelation at one ruthenium(II) site as revealed by separate ruthenium(II)/(III) waves at 0.03 and 0.54V vs. n.h.e. A second equivalent of 2,2-bpy (1:2) is initially stored and retained as the [Zn(2,2-bpy)]2+ complex. Further addition of 2,2-bpy initiates coordination at the second ruthenium(II) site. [Ru2(ttha)-(2,2-bpy)(H2O)]2– forms a strong ion-pair with zinc(II) that is in rapid equilibrium with the Zn(H2O)62+/Zn(2,2-bpy)]2+ pool. The solubility of the ion-pair is low. The ion-pair exhibits a shifted ruthenium(II)/(III) wave at 0.60V. Higher amounts of 2,2-bpy recomplex the zinc(II), solubilizing the complex and returning the E1/2 value to 0.54V. Other ligands which either have a higher affinity for ruthenium(II) centres than for zinc(II) as bidentate donors (1,10-phenanthroline), or ligands that cannot form bidentate zinc(II) complexes [(2-methylpyrazine, 4,4-bipyridine (4,4-bpy), and 2,3-bipyridine (2,3-bpy)] do not exhibit the unusual competition by zinc(II). These ligands all add statistically to the ruthenium(II) centres forming 1:2 complexes with 1:2 stoichiometries. 1H-n.m.r. studies of the Ru(II)polyaminopolycarboxylate complexes [RuII(hedta)(H2O)]– complex, and [Ru2(ttha)(H2O)2]2– itself, reveal that substitution of 2,3-bpy at ruthenium(II) sites occurs with an initial kinetic split between the pyridyl rings of the 3- less-hindered and 2-more-hindered ring. A slower rearrangement occurs, producing the isomer of the more-hindered 2-substituted ring. A process is driven by forming a more -accepting system when ruthenium(II) binds to the 2-ring of 2,3-bpy. Understanding the unusual influence of zinc(II) on the substitution of 2,2-bpy with [Ru2(ttha)(H2O)2]2– clarifies the nature of the 1:1 complex – namely that the 2,2-bpy becomes bidentate at one ruthenium(II) centre rather than serving as a trans-bridging ligand between both ruthenium(II) centres within one [Ru2(ttha)]2– unit.     

Benzoylation of 1,4-diaza-1,3-butadienes: Synthesis of representatives of a new chemical class—1,2-diamino-1-chloroethylenes

Trans-N,N-dialkyl-N,N-dibenzoyl-1,2-diamino-1-chloroethylenes — the first representatives of a new chemical class — and N,N-dialkyl-N,N-dibenzoyl-1,2-diaminoethylenes were obtained by benzoylation of N,N-dialkyl-1,4-diaza-1,3-butadienes. On increase in pressure to 10,000 atm, the yields of the N,N-dibenzoylated 1,2-diamino-1-chloroethylenes increase, and those of the N,N-dibenzoylated 1,2-diaminoethylenes decrease.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2038–2041, September, 1989.     

Kinetics of ferrocenoylacetonato substitution from (1,5-cyclooctadiene)(ferrocenoylacetonato)rhodium(I) with 2,2′-dipyridyl and derivatives of 1,10-phenanthroline

Treatment of MeOH solutions of [Rh(cod)(fca)] (cod = 1,5-cyclooctadiene, fca = ferrocenoylacetonato) with seven derivatives of 1,10-phenanthroline (N,N), as well as with the (N,N) ligand 2,2-dipyridyl, gave [Rh(cod)(N,N)]⁺. The kinetics of these reactions follow the rate law: Rate = k[Rh(cod)(fca)[N,N] The temperature dependence of all the studied substitutions resulted in activation entropies, S , more negative than –100 J K^–1 mol^–1 which is indicative of associative mechanisms. The pK _a's of the incoming phenanthroline derivatives were between 3.03 and 6.31 but did not influence the reaction rate to any significant extent. This implies that the rate determining step during the substitution involves Rh—O bond breaking and not Rh—N bond formation. Substitution of fca with 2,2-dipyridyl was slightly faster (k = 118 dm³ mol^–1 s^–1) than with the 1,10-phenanthroline derivatives (k _average = 14.2 dm³ mol^–1 s^–1) and may be attributed to the free rotation capability of the two pyridyl rings about the 1-1 carbon–carbon axis in 2,2-dipyridyl. 1,10-Phenanthroline cannot rotate about the corresponding carbon axis.     

Determination of labeled cyclic 3′,5′-adenosine monophosphate by sub- and super-equivalence isotope dilution

Cyclic 3, 5-adenosine monophosphate labeled with a radioactive isotope was determined in the 0.05–4.1 pmol.ml^–1 concentration range.     

Selective aziridination of olefinic esters

Summary Oxidation of 3-amino-2-isobutylquinazoline-4-one (2) with lead tetraacetate at –20°C gave N-acetoxyamino-2-isobutylquinazolin-4-one (3), which selectively aziridinated olefinic esters to yield substituted 1-(2-isobutylquinazolin-4-one-3-yl)-aziridine-2-carboxylates5a–q.

---

Selektive Aziridinierung von olefinischen Estern

Zusammenfassung Oxidation von 3-Amino-2-isobutylchinazolin-4-on (2) mit Bleitetraacetat bei –20°C ergab N-Acetoxyamino-2-isobutylchinazolin-4-on (3), welches mit verschiedenen olefinischen Estern selektiv substituierte 1-(2-Isobutylchinazolin-4-on-3-yl)-aziridin-2-carbonsäureester5a–q lieferte.

     

Some remarks on the periodical change of the stability constants of the lanthanide complexes

The correlations between the values of the lgK (K = stability constant of the lanthanide complex) and the reciprocal of the ionic radius 1/r or the sum of the ionization potentials ₁ ³ I for the lanthanide ions were reviewed for different ligands. A straight-line relationship (lgK – lgK)/lgK vs. (1/r – 1/r)/(1/r) or vs. ( ₁ ³ I – ₁ ³ I)/ ₁ ³ I was found within the tetrads La-Nd, Gd-Ho, and Er-Lu.

---

Bemerkungen zum periodischen Wechsel der Stabilitätskonstanten von Lanthaniden-Komplexen

Zusammenfassung Es wurde eine Übersicht der Korrelationen zwischen den Werten von logK (K = Stabilitätskonstante der Lanthanidenkomplexe) und den reziproken Ionenradien 1/r oder der Summe der Ionisierungspotentiale ₁ ³ I für die Lanthanidenionen für verschiedene Liganden gegeben. Dabei wurde eine lineare Korrelation für (lgK – lgK)/lgK gegen (1/r – 1/r)/(1/r) oder gegen ( ₁ ³ I – ₁ ³ I)/_1/3 I innerhalb der Tetraden La-Nd, Gd-Ho und Er-Lu aufgefunden.

     

Reaction of 2-methyl-4,5-dihydrofuran with hydrogen chloride

Reaction of 2-methyl-4,5-dihydrofuran with HCl at 0°C yields 5-chloro-2-pentanone (13%) and 1-(2-methyltetrahydrofuryl-2)-5-chloro-2-pentanone (27%) and at 200° 5-chloro-2-pentanone exclusively.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. I. M. Gubkin State Petroleum and Gas Academy, 117917 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2188–2191, September, 1992.     

Demetallation of coordination compounds of nickel with tetradentate ligands based on S-substituted isothiosemicarbazides

The passage of dry gaseous hydrogen chloride through chloroform solutions or acetone suspensions of S-substituted N¹,N⁴-di(salicylidene)isothiosemicarbazidates of nickel (Ni(LRR)) has led to a demetallization reaction with the liberation in the free state of S-substituted N¹,N⁴-di(salicylidene)isothiosemicarbazides with the general formula N₂LRR (where R is H and R is CH₃ (I); R is H and R is C₂H₅ (II); R is H and R is C₃H₇ (III); R is H and R is C₇H₇ (IV); and R is CH₃ and R is CH₃ (V)). The IR spectra of (I-IV) each showed bands characteristic for an aromatic ring and groups in the 1600–1500 cm^–1 region, with a band of the deformation vibrations of an OH group at 1300 cm^–1. The PMR spectra in CDCl₃ each had two singlets at 12.15-11.25 and 9.00-8.36 ppm which were assigned, respectively, to the protons of an OH group and those of a =CH group. A multiplet in the 7.70-6.83 ppm region belonged to the protons of benzene rings. In the region of lower fields there were the signals of the substituents R and R. In the mass spectra of (I-V), the peaks of the molecular ions, and also the characteristic fragments OH, R, SR, and HSR have been detected.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 5, pp. 604–608, September–October, 1985.     

1,2-bis(2',6'-dimethyl-i',3'-dioxa-6'-aza-2'-silacyclooctyl-2')ethane and the corresponding ethylene and acetylene derivatives

Conclusions The reaction of 1,2-bis(methyldimethoxysilyl)ethane and the corresponding ethylene and acetylene derivatives with bis(2-hydroxyethyl)methylamine gives 1,2-bis(2,6-dimethyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)ethane and the corresponding ethylene and acetylene derivatives. Analogously, 1,2-bis(vinyldimethoxysilyl)acetylene gave 1,2-bis(2-vinyl-6-methyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)acetylene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1420–1421, June, 1988.     

Synthesis and properties of 2,2′-dipyridyl and 4,4′-dipyridyl complexes with thulium salts

Summary New complexes of 2,2-dipyridyl and 4,4-dipyridyl with thulium salts TmX ₃ (whereX=Cl^–, Br^–, NO ₃ ^– , NCS^–, and ClO ₄ ^– ) have been prepared and their solubilities in water at 21 °C were determined. The IR spectra of these compounds are discussed. The conditions of thermal decomposition of the complexes were also studied.

---

Synthese und Eigenschaften von 2,2-Dipyridyl- und 4,4-Dipyridylkomplexen mit Thuliumsalzen

Zusammenfassung Es wurden neue 2,2-Dipyridyl- und 4,4-Dipyridyl-Komplexen mit Thuliumsalzen TmX ₃ (X=Cl^–, Br^– No ₃ ^– , NCS^–, ClO ₄ ^– ) dargestellt und ihre Wasserlöslihkeit bei 21 °C bestimmt. Die IR-Spektren werden diskutiert. Das thermische Verhalten der erhaltenen Komplexe wurde untersucht.

     

Amplification method for the spectrophotometric determination of phosphorus

An amplification method with ion-exchange pre-separation for the spectrophotometric phosphorus determination in various alloys is described. Phosphorus is converted into molybdophosphoric acid, separated by selective extraction and back-extracted into the aqueous phase. The molybdenum is liberated by alkaline decomposition of the heteropoly acid. The spectrophotometric measurement is based on the reaction of molybdenum(VI) with 2,2-biquinoxalyl. High molar absorptivity of 1,1-dihydro-2,2-biquinoxalylene (=3.3 · 10⁴ L mol^–1 cm^–1) and the twelve-fold amplification guarantee high precision and makes the determination of phosphorus in the 1–6 g level possible.     

Mass-spectrometric study of esters of marmesin and saturated acids

Summary From a methanolic extract of the roots ofPrangos biebersteinii Karjag., in addition to substances found previously, two other components — (I) and (II) — of the coumarin series have been isolated.The results of a study of their IR, NMR, and mass spectra, and also their chemical properties have enabled (I) to be identified as the known coumarin umbelliferone and the structure of 5-(1,2-dihydroxy-isopropyl)-4,5-dihydrofuro-2,3:7,6-coumarin to be proposed for (II), which has been named prandiol.Leningrad Sanitary-Hygenic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 574–577, September–October, 1974.