Complexation of Oleuropein and trans-Cinnamic Acid with Cyclodextrins

The complexation of oleuropein and trans-cinnamic acid with -, -, and -cyclodextrin has been studied in aqueous model systems by light scaterring. The influence of various parameters (pH, concentration, reaction time, nature of cyclodextrin) has been thoroughly examined. The formation of binary (1:1) inclusion complexes and the higher inclusion ability of -CD for both compounds has been indicated. Trans-cinnamic acid was extracted from olive olive oil following its complexation with -CD at satisfactory recovery levels.     

Induced circular dichroism spectra of the cyclodextrin complexes with 2-Thioxo-1,3-benzodithiole and 2-Selenoxo-1,3-benzodithiole

The induced circular dichroism (ICD) spectra of -cyclodextrin (-CD) complexes with 2-thioxo-1,3-benzodithiole and 2-selenoxo-1,3-benzodithiole have been measured. From the signs of the ICD spectra of both complexes, the polarization directions for the excited states have been investigated.     

A quantum-mechanical study of the interaction of methylglyoxal with guanine

Ab initio self-consistent field molecular orbital computations on the relative stabilities of the different possible intermediate adducts for the reactions between methylglyoxal and guanine, as well as the evaluation of the relative stabilities of the two different possible final cyclic products (IIIb and IIIc) point all to the conclusion that it is the addition product in which the methyl group is close to the amino nitrogen which is the most stable one.     

Semiempirical calculations on cyclodextrins

In order to obtain information on the different reactivities of the hydroxyl groups of the glucopyranose units or the inclusion complex formation mechanism, the charge distributions and the geometrical constraints must be determined. Geometry optimizations, employing the AM1 semiempirical method, have been performed for -D-glucopyranose, –,–, and -cyclodextrins. The data obtained were compared with X-ray diffraction data of the cyclodextrins.Dedicated to Professor József Szejtli.     

Investigation of the Regio- and Stereochemistry of the [2+4] Cyclocondensation of 3,4-Dihydroisoquinolines with 2-Acetyl-4-hydroxycyclohexane-1,3-dione. Synthesis and Properties of the Regioisomeric 15- and 17-Hydroxy Derivatives of 8-Aza-D-homogona-12,17a-diones

The 15- and 17-hydroxy derivatives of 8-aza-D-homogona-12,17a-diones were obtained by the annelation of 3,4-dihydroisoquinolines with 2-acetyl-4-hydroxycyclohexane-1,3-dione. It was shown that the reaction proceeds stereoselectively with the intermediate formation of 9,15- and 9,17-trans isomers. The probable mechanism and certain aspects of the interconnection between the structural and physicochemical characteristics of the obtained compounds are discussed.     

Synthesis of γ-Cyclodextrin Pyrene-Labeled at the Hetero Rim and Its Use in Fluorescent Molecular Sensing

Fluorogenic active host labeled at the upper and lower rims of -cyclodextrin, namely, mono-3^A-deoxy-3^A-pyrenebutylamido-6^X-O-mono-pyrenebutylate-mono-altro--cyclodetrin (mixture -1,X = A, B, C, D, E, F, G, or H), has been synthesized in order to investigate their host-guest complexation with steroidal compoundsusing fluorescence spectra. Monomer and excimer fluorescence was observed for mixture host. Inclusion of a guest molecule in the cyclodextrin cavity resultedin increased monomer fluorescence and decreased excimer fluorescence. The extent of monomerand excimer fluorescence variations ofmixture -1 with the guestwas used as an indication for the sensing ability. The guest inducedfluorescence changes were measured for 10^-7 M solutions of mixture -1.The values I/I ⁰ , where I ⁰ and I are fluorescence intensities in the absence and presence of a guest, respectively, and I is I ⁰ - I, were then used to describe the sensing ability.     

Essential Oil Constituents of Satureja boissieri from Turkey

Water-distilled essential oil from the aerial parts ofS. Boissieriwas analyzed by GC/MS. Forty - five components were characterized representing 97% of the oil. The main components were identified as carvacrol (40.8%),-terpinene (26.4%), andp-cymene (14.5%).     

Non-empirical SCF MO studies on the protonation of biopolymer constituents

Proton affinities of a large number of tautomeric adenine and guanine structures have been calculated using theab initio Hartree-Fock-Roothaan SCF method. For guanine, and to a lesser extent for adenine, it is likely that several protonated forms may co-exist in acidic solutions. Protonation at the free adenine and guanine positions in DNA may introduce effective acceptor levels between the energy bands of the polymer that may cause fundamental changes in the conduction properties of DNA.     

Acidity scale for strong Bronsted acids referred to their complexes with water and in the Gaseous phase

CNDO/2 calculations on AH...B complexes in the gaseous phase (AH = strong acids, B = water) gives the following order H₂O < HF < HCl < HSO₃CF₃ < H₂SO₄ < HSO₃F < HClO₄ < H₃O⁺ if we take as reference the Wiberg residual indexp(H... O). Other properties and in particular the charge transfer behave in the same fashion. Charge variations for each atom give an explanation for the Pauling rule for the oxygenated acids.

     

Isocamphanyl-γ-butyrolacton,ein neuer Sandelholzriechstoff

The synthesis of a new compound with a sanddalwood odour is described. The synthesis of the lactone1 has been designed by molecular considerations: a bicyclus with a side chain containing 5–7 carbon atoms and an oxygene containing osmophoric group. One route to synthesize1 leads from the ketone3 via theMannich base4 to the -ketonitrile6 which after hydrolysis to the -keto acid7 and reduction of the latter cyclises spontaneously to1. A shorter route starts from the -bromoketone13 which could be transformed by malonic ester synthesis into7. Other synthetic routes, e.g. cyanoethylation to the homologous -lactone16 aldol condensation, alkylation, carboxymethylation and carboxyethylation of3 failed as well as the preparation of the oxazoline protected 3-bromopropionic acid for aGrignard synthesis with3. 1 exhibits a sweet, warm odour, of sandalwood with an interesting note of cedarwood.

Teil der Diplomarbeit vonSchindler, K., Universität Wien, 1979.     

Theory of isomer shift in hemin

Using the self-consistent charge extended Hückel procedure, the charge density difference at Fe⁵⁷ nucleus, between hemin and Fe⁺³ ion is calculated. This is combined with the recent value of the calibration constant, –0.23±0.02a ₀ ³ mm/sec to obtain an isomer shift of –0.374 mm/sec between hemin and Fe⁺³ in good agreement with the value –0.392 mm/sec derived from experimental data and the calculated value of the isomer shift of Fe⁺³ with respect to K₃FeF₆ from first principle covalency investigations in the latter compound. is composed of contributions from core and valence electrons of the same order of magnitude, with the latter being more than one-half of the former. The core contribution is composed of a number of terms of comparable magnitude and differing signs, whose significance is discussed.Supported by grant HL 15196-02 from the Heart and Lung Institute of National Institute of Health.     

Diisophorone and related compounds. Part 18 ring contraction in diisophorone by theFavorski reaction

The action of strong alkalis or alkoxides on 4,8-dibromo-1-carboxydiisophor-2(7)-en-3-one produces 1,3-dicarboxyneodiisophora-2,7-diene (or its esters) by a ring-contraction of theFavorski-type; the products are derivatives of tricyclo[6.3.1.0^2,6]dodecane. Hydriodic acid converts the dienedioic acid by partial saturation of the conjugated 2,7-diene system into the 2(7)-mono-olefinic dioic acid; the carboxyl groups of both series of compounds undergo esterification, anhydride formation and reduction in the normal manner. The¹³C nmr spectra of the novel ring-contracted compounds are interpreted, chiefly by reference to those of their diisophorone-precursors, as are their fragmentation patterns under electron impact.

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Diisophoron und verwandte Verbindungen, 18. Mitt.: Ringverengung in Diisophoron mittelsFavorski Reaktion

Zusammenfassung 4,8-Dibromdiisophor-2(7)-en-3-on-1-carbonsäure wird von Alkalien oder Natriumalkoholaten durch eineFavorski-artige Ringverengung in Neodiisophora-2,7-dien-1,3-dicarbonsäure (oder deren Ester) verwandelt; die Reaktionsprodukte sind Abkömmlinge des Tricyclo[6.3.1.0^2,6] dodekans. Partielle Sättigung der konjugierten Doppelbindungen mittels Iodwasserstoffsäure ergibt die entsprechenden 2(7)-Mono-olefine. Veresterung, Anhydridbildung und Reduktion der Carboxylgruppen beider Verbindungsreihen verlaufen normal. Die¹³C-Kernresonanz-und Massenspektren der neuen Strukturen werden auf Grund bekannter Spektren der verwandten Diisophoron-Reihe gedeutet.

     

A theoretical study of electrophilic reactions

The electronic structures of protonated formyl and acetylium cations and their deprotonation paths leading to HCO⁺, COH⁺ and CH₃CO⁺have been studied by means of ab initio calculations. The results support Olah's theory that dipositive species can be the de facto reagents in electrophilic reactions.     

On the use of pseudopotentials in molecular calculations

A series of tests was performed of the Kahn-Goddard-Melius-Topiol pseudopotentials in view of their utilization with small contracted basis sets in molecular computations. The effects of inner-shell separability and of basis set contraction are underlined. The utilizability of Topiol's valence least-squares fitted Gaussian basis sets is studied.     

A note on the attainability of states by equalizing processes

In this paper, we consider regions of attainability in certain state spaces as a function of the initial state under a well-defined and physically relevant class of processes. These processes are the continuous and chaos-enhancing processes (in the sense of Ruch and Uhlmann). It turns out that these sets have complicated geometrical structures: They are polyhedra which are generally non-convex. The proof — a rather geometrical one — is given. A theorem of Hardy, Littlewood, and Polya and properties of bistochastic matrices are used crucially.     

The effect of Fe(II) ions on the 1,10-phenanthroline and neocuproine intercalates of γ-zirconium phosphate

1,10-Phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (neocuproine), and 4,7-dimethyl-1,10-phenanthroline have been intercalated between layers of -zirconium phosphate (-ZrP). The observed interlayer distances are not a simple function of the size of guest molecules. Despite the fact that -ZrP takes up very few Fe²⁺ ions, the phen and neocuproine intercalates do take up some Fe²⁺ ions without further changes in the interlayer distances. The chemical environments around Fe²⁺ ions between layers of the intercalates were investigated by⁵⁷Fe Mössbauer spectroscopy. A fairly large fraction of the Fe²⁺ ions was found to be in a high-spin state. The low-spin [Fe(phen)₃]²⁺ ions are also ion exchanged on -ZrP, with the expansion of the interlayer up to 19.9 Å.     

Electron diffraction analysis of Al2O3 of gamma-type

Summary A diffraction pattern was registered from an active catalyst of -Al₂O₃ which was characterized by lattice vacancies and by particle size of about 100 Å. A given preparation of alumina proved to be a mechanical mixture consisting of -oxide, corundum and hydroxide. A composite particle, where the surface of Al was covered with -Al₂O₃, was detected by an electron diffraction procedure with wavelength fluctuation.

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Elektronenbeugungsanalyse von -Al₂O₃

Zusammenfassung Ein Beugungsbild wurde von einem aktiven Katalysator vom -Al₂O₃-Typ aufgenommen, der durch Gitterfehler und Teilchengrößen von ca. 100 Å charakterisiert war. Ein weiteres Präparat erwies sich als mechanisches Gemisch, das aus -Oxid, Korund und Hydroxid bestand. Ein zusammengesetztes Teilchen, bei dem die Oberfläche von Al mit -Al₂O₃ bedeckt war, wurde mit Hilfe eines Elektronenbeugungsverfahrens mit Wellenlängenfluktuation erfaßt.

The author would express here his deep gratitude for the abundant support received from Prof. Dr. T. Yamauchi and Prof. Dr. H. Tagai, Director of the National Institute for Researches in Inorganic Materials, Japan.     

Ab initio studies of the low-lying π-states of borazine

Self-consistent-field and configuration-interaction studies were performed on borazine, using a double-zeta basis set augmented by six diffuse -functions. Low-lying singlet and triplet states of the A ₁ , A ₂ and E species were calculated, corresponding to ^* excited valence and Rydberg states. A selection out of singly and doubly excited configurations relative to a set of reference configurations was made for each species. Calculated vertical excitation energies (in eV) are 7.12 for ¹ A ₂(V), 8.45 for ¹ E (3p-R), 8.57 for ¹ A ₁(V), 8.9 for ¹ E(V-R), 9.55 for ¹ E(3d-R), 6.98 for ³ A ₁(_V), 7.27 for ³ E(V), 7.82 for ³ A ₂(V), 8.30 for ³ E(3p-R), and 9.5 for ³ E(3d-R), where V and R refer to valence or Rydberg character. The results are compared with experimental excitation energies, previous ab initio studies of borazine, and with recent ab initio studies of benzene.Dedicated to Professor Dr. H. Hartmann on the occasion of his 65th birthday.     

A new detection method for purines in thin-layer chromatography

Summary The separation of some purines by thin-layer chromatography, utilizing precoated plates with Silicagel R as stationary phase and the following mobile phases: i-butanol: methylethylketone: ammonium hydroxide 25%: water (40252015) and n-propanol: ammonium hydroxide 25%: water (80155) is reported.Visualisation of the spots has been achieved by spraying with aqueous 1% uranyl acetate and irradiating with UV both at 254 and 366 nm. The visual detection of a spot was 0.01 g.