Analysis of the globins from fast human haemoglobins by isoelectrofocusing on polyacrylamide gel rods

The globins from all fast haemoglobin (Hb) components obtainable by Bio-Rex 70 cation-exchange chromatography were examined by isoelectrofocusing on polyacrylamide gel rods with 8.0 mol/l urea. From this analysis HbA1a1 and HbA1a2 seem to be very heterogeneous components. HbA1b is separable into two components, one of which is varied in both the beta chains. Between HbA1b2 and the well-known HbA1c components two chromatographic peaks are separated, one with a noticeable percentage of glucosylated beta chain and one that probably contains HbF. HbA1c has both beta chains glucosylated, while HbA1x seems to be a beta monoglucosylated Hb form. Finally, the early part of the HbAo peak has a large amount of glucosylation on both alpha and beta chains.     

Fitting tabulated current functions to linear-sweep voltammograms

A procedure is described for fitting tabulated theoretical current functions to linear-sweep voltammograms. The method, suitable for a small microcomputer, employs linear extrapolation between current function values, and non-linear regression for minimizing deviations between experimental and theoretical currents. Examples of its use for confirmation of simple electrode reaction mechanisms and estimation of electrochemical parameters are described.     

Synchronization of signal sampling with liquid pulsation in systems with peristaltic pumps

Method and electronic circuitry are described for synchronization of analytical signal sampling with pulsation of liquid flow in systems with a peristaltic pump. The technique is illustrated for cathodic stripping voltammetry of manganese.     

Electrochemical systems for galvanic cells in organic aprotic solvents: V. Electrochemical behaviour of gamma-butyrolactone

Gamma-butyrolactone (GBL) was shown to decompose on the clean surface of Li, Na, K, and their amalgams. Polarization curves were obtained on Pt and “Kovar” electrodes at potentials from 4 to ?4 V vs. Li?Hg in 0.5 M LiClO₄ or vs. K?Hg in 0.5 M KPF₆. GBL was found to reduce electrochemically at potentials more positive than 1 V. Various passivation phenomena provoked by the decomposition of the solvent were observed, hindering cathodic deposition of the alkali metals from solutions of their salts in GBL. The presence of a high-molecular surfactant in the electrolyte suppresses the decomposition of GBL and suggests a path to the deposition of Li on the electrode.     

Zusammenh?nge zwischen Koordination und polarographischem Verhalten unterschiedlicher Alizarin S-Chelate

Zusammenfassung Alizarin S und seine 11-Metallchelate lassen sich an der Quecksilbertropfelektrode reduzieren. Aus der Beeinflussung der diffusionskontrollierten und der Adsorptionsstufe durch die Chelatbildung lassen sich Aussagen über die Konstitution und Ladung der adsorbierten Chelate machen: Beryllium wird in peri-, Aluminium und Gallium werden in ortho-Stellung des Alizarinmoleküls gebunden. Die 11-Chelate des Be und Al sind ungeladen. Das Ga-Chelat ist negativ geladen und enthält offensichtlich zusätzliche anionische Liganden.Wir danken der Deutschen Forschungsgemeinschaft, Bonn-Bad Godesberg, dem Minister für Wissenschaft und Forschung des Landes Nordrhein-Westfalen, Landesamt für Forschung, sowie dem Verband der Chemischen Industrie, Fonds der Chemie, für Sachbeihilfen.     

Synthesis and some properties of gem-dichlorocyclopropane carboxaldehyde acetals and cyclopropane carboxaldehyde acetals

α,β-Unsaturated aldehyde acetals add :CCl₂ (obtained in accordance with Makosza procedure) to form gem-dichlorocyclopropanecarboxaldehyde acetals (1) in high yields when the ratio of reactants is no less than 1:4. The addition of :CCl₂ to polyunsaturated aldehyde acetals in the above conditions proceeds regioselectively at double bonds enriched by electrons. Compounds 1 are reduced by sodium in liquid ammonia to give cyclopropanecarboxaldehyde acetals (2). Both 1 and 2 are hydrolized by dilute H₃P0₄ to the corresponding aldehydes and are added to vinyl ethers in the presence of BF₃·Et₂O to produce only 1:1 adducts which are hydrolyzed by a mixture of AcOH-AcONa-H₂O to give β-formylcyclopropanes which were previously unknown.     

Marine adhesives. IV: Hexosamine content of Balanus eburneus adhesive

The adhesive secreted by the barnacle, Balanus eburneus, has been demonstrated to contain two hexosamines, glucosamine and galactosamine. Degradation of the hexosamines during hydrolysis of the adhesive appears to be the reason why previous studies of the adhesive have indicated the absence of hexosamines, or the presence of only one hexosamine.     

Anionic polymerization of 1,2-butylene oxide

Anionic polymerizations of 1,2-butylene oxide were carried out in vacuum-sealed dilatometers in the range of 30–60°C. Potassium terbutoxide and dimsyl sodium were used as initiators; dimethyl sulfoxide (DMSO) and mixtures of DMSO with tetrahydrofuran were solvents. The polymer products were analyzed by gel permeation chromatography and infrared spectroscopy. The object of the investigation was to obtain information on the mechanism of the reaction and to elucidate some of its kinetic aspects. It has been shown that the polymerizations occur by two different processes, depending on the choice of experimental conditions. One of the processes involves free ions and ion-pairs, the other, ion-pairs alone. In the first case, where dimethyl sulfoxide is used as solvent, the order of the reaction with respect to the initiator concentration far exceeds unity (～1.8), while in the second case, involving mixed solvents, the order of the reaction, for all practical purposes, is one.