Hypepontine,a new quaternary alkaloid with antimicrobial properties

Abstract

New isoquinoline alkaloid hypepontine (1) together with a five known compounds, were identified in Hypecoum ponticum Velen, the partial synonym of Hypecoum procumbens L. The structure of the new substance was elucidated based on spectroscopic evidence. The tertiary and quaternary alkaloid mixtures as well as the isolated alkaloids were evaluated for their antibacterial and antifungal activity. The result revealed that the crude alkaloid mixture containing quaternary isoquinoline alkaloids showed potent antifungal and antibacterial activity.     

Measurements of π+p,K+p and pp elastic scattering)

The paper presents the results on differential cross sections for elastic scattering of 7⁺-, K⁺-mesons and protons on protons in the 4-momentum transfer squared range 0·08 ¦t¦ 1·0 (GeV/c)² and incident particle momentum of 29 and 43 GeV/c for pions and kaons and 29, 43, 50 and 65 GeV/c for protons. The measurements were taken with the spectrometer Sigma, installed in the positive beam of the IHEP accelerator.Presented by F. A. Yotch at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.The authors would like to express their gratitude to A. A.Logunov, Yu. D.Prokoshkin, L. D.Soloviev and V. A.Yarba for their support of this experiment. We are indebted to CERN Administration for giving us a permission to use a part of equipment of the CIBS spectrometer and to W.Kienzle for useful discussions.     

New trans/cis tetrahydroisoquinolines. 2. trans‐ and cis‐3‐(1‐methyl‐1h‐pyrrol‐2‐yl)‐1‐(2H)‐oxo‐2‐phenethyl‐1,2,3,4‐tetrahydroisoquino‐lin‐4‐carboxylic acids and subsequent transformations

Stereochemical course of the reaction of homophthalic anhydride and N‐(1‐methyl‐1H‐pyrrol‐2‐yl‐methylidene)‐phenethylamine was studied. Mixtures of the expected trans‐ and cis‐1,2,3,4‐tetrahydroiso‐quinoline‐4‐carboxylic acids trans‐ 4 and cis‐ 4 were obtained along with by‐products 5 and 6 . The ratios of all products and the diastereomers, obtained under different reaction conditions, were established by pmr. THF as a solvent and ultrasonic treatment are applied for the first time in the reaction of this type. The reaction was made diastereoselective towards any isomer. The carboxylic group of trans‐ 4 was transformed in four steps into various cyclic amino‐methyl groups yielding numerous new tetrahydroisoquinolinones trans‐ 10a‐i incorporating a given fragment of pharmacological interest. Reduction of 10a‐i was studied.     

Structure of binary mixtures of ethylene-vinylacetate copolymers

The method of differential scanning calorimetry was used to analyze the structure of binary mixtures of ethylene and vinylacetate copolymers with different contents of reagent monomers. The anomalous deviation of the degree of crystallinity from additivity in the system is found and a possible interpretation of this experimental fact is suggested.     

Low-Temperature Catalytic Oxidation of Sulfide Ions in Aqueous Solutions on a Ni-Oxide System

Catalytic oxidation of sulfide ions in aqueous solutions by air oxygen has been investigated using a Ni-oxide system as a catalyst. The kinetics and the selectivity of the oxidation process were studied by varying the pH, catalyst amount and reaction temperature. A reduction/oxidation mechanism of the reaction has been supposed comprising interaction between the surface active oxygen of the catalyst and HS^– and reoxidizing of the reduced catalyst by the dissolved oxygen. The results obtained show that the Ni-oxide system is a promising catalyst for practical application.     

Stabilization of over-stoichiometric Mn in layered Na2/3MnO2

Sodium manganates with nominal composition Na_2/3MnO₂ were prepared by solid state reaction between Na₂CO₃ and MnCO₃ at 1000 °C. The composition and structure of Na_xMnO₂ were controlled by the rate of cooling from the temperature of preparation. This is a consequence of the capability of Na_2/3MnO₂ to accommodate over‐stoichiometric Mn⁴⁺ ions up to 12.5%. Structural characterization was carried out by XRD powder diffractions, TEM analysis and Raman spectroscopy. The composition and oxidation state of manganese were determined by chemical analysis and magnetic susceptibility measurements. The manganese distribution in the layers was analysed using electron paramagnetic resonance (EPR) spectroscopy. By quenching from 1000 °C, the orthorhombic distorted modification is stabilized. A phase separation into orthorhombic and hexagonal modifications takes place when Na_2/3MnO₂ is slow cooled. The structure changes are concomitant with an increase in the oxidation state of Mn. The over‐stoichiometric Mn⁴⁺ ions are accommodated in the hexagonal modification by creation of vacancies in the MnO₂‐layers.     

Using silver chloride emulsions as adaptive optical filters for image processing

Fine-grain high-sensitive silver chloride emulsions with print-out effect were synthesized for the purposes of adaptive amplitude spatial frequency filtering of images. Their characteristics were studied and experiments were conducted for contrast enhancement and contouring.     

Spectrophotometric determination of trace iron by using its catalytic effect on the N-phenylanthranilic acid-potassium periodate reaction.

The analytical features of the reaction between N-phenylanthranilic acid (PAA) and potassium periodate in acidic medium are explored with the aim of improving the catalytic kinetic determination of iron in water samples. In the presence of Fe(II, III), PAA is oxidized by potassium periodate in a formic acid medium to form a violet-colored compound. The reaction is followed spectrophotometrically by measuring the increase in the absorbance of the oxidation product at 525 nm. The variables that affected the reaction rate were investigated and the reaction conditions were established. Calibration graphs are linear in the range of concentrations 2 - 500 ng mL(-1). As low as 10(-8) mol L(-1) Fe(II, III) can be easily determined by the fixed time method. The established catalytic method was successfully applied to the determination of iron in tap water and in pharmaceutical samples.     

Automatic alignment of individual peaks in large high-resolution spectral data sets

Pattern recognition techniques are effective tools for reducing the information contained in large spectral data sets to a much smaller number of significant features which can then be used to make interpretations about the chemical or biochemical system under study. Often the effectiveness of such approaches is impeded by experimental and instrument induced variations in the position, phase, and line width of the spectral peaks. Although characterizing the cause and magnitude of these fluctuations could be important in its own right (pH-induced NMR chemical shift changes, for example) in general they obscure the process of pattern discovery. One major area of application is the use of large databases of (1)H NMR spectra of biofluids such as urine for investigating perturbations in metabolic profiles caused by drugs or disease, a process now termed metabonomics. Frequency shifts of individual peaks are the dominant source of such unwanted variations in this type of data. In this paper, an automatic procedure for aligning the individual peaks in the data set is described and evaluated. The proposed method will be vital for the efficient and automatic analysis of large metabonomic data sets and should also be applicable to other types of data.     

Isolated photon cross section in p&pmacr; collisions at radicals = 1. 8 TeV

We report a new measurement of the cross section for the production of isolated photons with transverse energies ( E(gamma)(T)) above 10 GeV and pseudorapidities |eta|<2.5 in p&pmacr; collisions at sqrt[s] = 1.8 TeV. The results are based on a data sample of 107.6 pb(-1) recorded during 1992-1995 with the D0 detector at the Fermilab Tevatron collider. The background, predominantly from jets which fragment to neutral mesons, was estimated using the longitudinal shower shape of photon candidates in the calorimeter. The measured cross section is in good agreement with the next-to-leading order QCD calculation for E(gamma)(T) greater, similar36 GeV.