Oxydative Kupplung von Indolinen und 1,2,3,4-Tetrahydrochinolinen mit Kaliumpermanganat. 153. Mitteilung über Alkaloide

It is shown that treatment of indolines like 4a-methyl-1,2,3,4,4a,9a-hexahydrocarbazole ( 1 ) and even indoline-alkaloids like 5 or 6 (cf. scheme 1) with KMnO₄ in boiling acetone solution leads to the indolenines 10, 29 and 33 , respectively, and, in relatively high yields, to N,N′- or C,N-coupling products (cf. schemes 2 and 5). The results of the oxidation of 6- or 8-methoxy-indolines are shown in schemes 3 and 4, respectively. Analogous ‘dimeric’ dehydrogenation products are observed when tetrahydroquinolines ( 8 and 9 , resp.) are treated with KMnO₄ (cf. schemes 7 and 8, resp.). The formation of the bis-compounds is almost certainly due to the coupling of two intermediate indolenyl or tetrahydroquinolyl radicals. The cleavage of the hydrazine derivatives 11 or 17 (scheme 9) also leads to ‘dimeric’ C,N-coupling products. By heating the hydrazine derivative 17 with aqueous HCl, a complete cleavage into indoline 2 and the indolenines 16 and 20 is observed. The reaction is rationalized in scheme 10. So far no naturally occurring alkaloids related to the above mentioned C,N-coupling products have been found.     

Preparation of 4-aryl-1,2,3,4-tetrahydro-3,3-dimethylisoquinolines and 1,2,3,4-tetrahydro-3,3-dimethyl-4-phenylbenz[h]isoquinolines

Synthetic procedures to prepare a number of 4-aryl-1,2,3,4-tetrahydro-3,3-dimethylisoquinolines and their benzo-homogues 3 through a series of intermediates are described. The condensation of α-(1-amino-1-methylethyl)arylmethanols 5 with arylaldehydes 6 gave imino derivatives 7 which on reduction with borohydride gave secondary amines 8 . The treatment of 8 with mineral acids gave the target compounds 3 . Biological activities of 3 are briefly discussed.     

The preparation of precisely defined lithium isotope mixtures

The need for accurate (< 0.06%) isotopic blends of ⁶Liand ⁷Li is explained and their preparation is discussed. It is shown that lithium must be determined at an accuracy level better than 0.035%. Four methods — acid-base titration with hydrochloric acid or benzoic acid, and weighing as sulphate or carbonate — were tested and improved for the precise and accurate analysis of lithium hydroxide solutions. The results of these four methods for a 0.1 M solution agreed within ± 0.02%. The preparation of pure isotopically enriched lithium hydroxide solutions, with specially purified cation- and anion-exchangers, is described. The prepared products contain as little as 100 μg of other alkali metals and 50 μg of alkaline-earth metals per gram of lithium, and are sufficiently free of anions to permit accurate chemical assay of lithium. No changes in the isotopic compositions of 99% ⁶Li or 99.99% ⁷Li were detected during the treatment.     

Analytical study of highly condensed non ionic surfactants. Separation on cation exchangers

Summary This study was aimed at optimizing the separation of non-ionic surfactants, resulting from the condensation of ethylene oxide with natural fatty alcohols in the C₁₆ and C₁₈ range (saturated and unsaturated), and presenting a high degree of condensation, i.e. 20 and 25 ethylene oxide units (Brij 99 and KM 25). The cation exchange stationary phase is a partially ionized silica, conditioned in different ways. We have studied the influence of the nature of cations on the separation selectivity. Cations studied included alkali metals (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺), alkaline earth metals (Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺), transition metals (Zn²⁺, Cd²⁺, Hg²⁺, Pb²⁺, Cu²⁺), and quaternary ammonium (NH ₄ ⁺ , NMe ₄ ⁺ ) ions as well as a proton (acetic acid). The influences of ionic strength, pH and addition of cosolvent were examined. A study of the influence of temperature on the system selectivity evidenced a strong interdependance of these two parameters. The optimized conditions [mobile phase: CH₃CN/H₂O (92/8), pH 7.4, sodium acetate 5.10^–3 M; temperature gradient between 25 and 50°C] allowed for the first time the distributions of Brij 99 and KM 25 to be obtained.     

Level-spacing distributions beyond the Wigner surmise

We introduce a dynamical system, for which it is possible to get such a large number of eigenvalues that deviations from Wigner's surmise are visible. The obtained level-spacing distribution agrees much better with the distribution derived from random matrix theory.     

Synthesis by the method of Merrifield of an actapeptide contained in lysozyme of hen egg-white (sequence Cys64--Gly71)

The solid-phase peptide synthesis of an octapeptide contained in hen egg-white lysozyme (sequence Cys (residue 64) to Gly (residue 71)) is reported. Each step of the synthesis was verified by amino acid analysis. Three main reaction products were obtained. The octapeptide (50% of the reaction products) was purified by two chromatographies on Dowex 50 × 2. The purified peptide was digested by an aminopeptidase and degradated by means of Edman' s method; this latter procedure has shown that the purified octapeptide still contained around 10% of a shorter peptide.     

Phototoxic and photochemical properties of sanguinarine.

Sanguinarine, a commercial drug exhibiting antimicrobial and antitumor properties, was studied with respect to its basic photochemical characteristics and also with regard to its phototoxicity to mosquito larvae (Aedes atropalpus). Sanguinarine proved to be clearly phototoxic to larvae, with an LD50 of 0.096 mg/mL with near UV exposure as compared with 23.3 mg/mL without. Flash photolysis experiments enabled the study of the triplet state of sanguinarine to be undertaken. Quenching by oxygen occurs with a rate constant of 6 x 10(9) M-1s-1 and time-resolved emission studies indicate that sanguinarine produces a significant amount of singlet oxygen (phi delta = 0.16) as does the isoquinoline alkaloid, berberine (phi delta = 0.25). These values represent the first direct quantitative measurements of photosensitization parameters of these compounds. Additionally, sanguinarine exhibits efficient electron donation properties, undergoing reaction with methyl viologen with a rate constant greater than 10(10) M-1s-1, but is a poor electron acceptor. Phototoxicity of sanguinarine can thus be explained in terms of its photosensitization properties.     

Goldstone theorem for bose systems

In three or more dimensions (3) it is proved that if the correlations decay faster than |x|^-(-20) then gauge symmetry breaking is excluded. In one and two dimensions (=1 or 2) the gauge symmetry is always preserved.