Über die Wechselwirkung des Katalysators und Cokatalysators mit dem Monomeren und Polymeren bei der kationischen Polymerisation des Isobutylens. I. Modellstudium der primären Deuterierung und isomerisierung des triisobutylens durch das system AlBr3/DBr

The course of the isomerization and deuteration into different positions of 1.1-dineopentylethylene by the AlBr₃/DBr system corresponds to the reaction of the deuteron and of AlBr₃ itself with the substrate. The possible role of this effect in the cationic polymerization of isobutylene is discussed.     

Modifizierung von homo- und copolymeren des epichlorhydrins durch polymeranaloge umsetzungen

Poly(epichlorohydrin) and poly(epichlorohydrin-co-ethylene oxide) were modified by reaction with potassium thiocyanate (KSCN), tetrabutylammonium p-toluenesulfinate (NBu₄SO₂C₇H₇) and tetrabutylammonium benzenesulfinate (NBu₄SO₂C₆H₅). Though the substitution of chlorine in the polymers with these nucleophilic reagents in most cases is accompanied by side reactions, appropriate reaction conditions allow degrees of substitution higher than 90% to be obtained. The glass transition temperature (T_g) of the thiocyanate-modified homo- and copolymer exhibits only a small increase with increasing degree of substitution. While the T_g of the original homo- and copolymer is observed at ?20°C and ?38°C, respectively, the glass transition of the highly substituted homopolymer occurs at ?12°C and for the copolymer at ?31°C. On the other hand, the thiocyanate-modified polymers show a remarkably higher decomposition temperature of about 250°C as compared with that of the unmodified polymers (160–180°C). In addition, the solubility is markedly influenced by the substitution. While the original homo- and copolymers are soluble in, e.g., benzene and toluene, the highly modified products are only soluble in polar solvents such as THF, acetone, DMSO and diglyme. Introducing sulfonyl groups, the resulting polymers exhibit a glass transition temperature increased to a greater extent. For the homopolymer with the highest degree of substitution (98,3%), a T_g of 73°C is observed. Concerning the decomposition temperature, a drastical increase up to 370°C occurs. Finally the influence of phase transfer catalysts on the described reactions was investigated.     

Lichtinitiierte polymer- und polymerisationsreaktionen, 26. Elektrophile ringöffnungsreaktionen zwischen glycidylethern und ketonen oder aldehyden initiiert durch photoinitiatorsysteme

By the irradiation of benzoin derivatives in the presence of arene diazonium salts or aryl iodonium salts cationic species are formed, which initiate ring-opening reactions of 2,3-epoxy-propyl (glycidyl) ethers in the presence of ketones or aldehydes. 1,3-Dioxolane formation dominates over homopolyaddition reactions of glycidyl ethers. This method forms dioxolane in satisfactory preparative yields. The quantum yields of disappearance of phenyl glycidyl ether in acetone (Φ_PGE) were measured in dependence of some system parameters. By the photolysis of benzil dimethyl ketal more catalytic species are produced as in the case of benzoin isopropyl ether or α-phenylbenzoin. The Φ_PGE values for diazonium salts are higher than for iodonium salts, with triphenylsulfonium salts the reaction failed. With the anions of iodonium salts the following sequence for Φ_PGE is observed: SbF₆^? > PF₆^? ? SbCl₆^? = BF₄^? = 0. Because the key step of the catalyst formation is an electron transfer reaction between radicals produced by the photolysis and the onium ions, the concentration of the salts influences Φ_PGE. Phenyl glycidyl ether reacts more rapidly than 2,2-bis(4-hydroxyphenyl)trimethylene diglycidyl ether and isobutyl glycidyl ether.     

Thermisch und UV-photochemisch initiierte hochdruckpolymerisation des ethylens, 1. Molmassen-mittelwerte

Ethylene is polymerized with thermal and with UV-photochemical initiation at temperatures between 130°C and 255°C up to pressures of 2500 bar. The conversions are between two and five percent. The degrees of polymerization as obtained from viscosity experiments are dependent on reaction temperature and pressure, but are insensitive to the kind of initiation, thermal or photochemical. These observations are explained by an equation which relates the degree of polymerization to kinetic parameters of the system which have partly been determined by independent experiments. From this equation, the activation energy and the activation volume of the transfer constant with the monomer, c_m, are determined to be E_a(c_m) = 43,9 ± 4 kJ · mol⁻¹ and ΔV^≠ (c_m)=20,1 ± 3 cm³ · mol⁻¹, respectively.     

Über die bildung und struktur von polymeren des α-cyanstyrols und des p-phenylendiacrylnitrils. II

By the reaction of p-phenylendiacetonitrile with formaldehyde in presence of alkali compounds crosslinked polymers were formed. The reaction of phenylacetonitrile with formaldehyde and reactions with model compounds indicated that these crosslinked polymers arise from phenylenacrylonitrile units by anionic polymerisation. Methoxy-hydroxymethyl. and imidoester endgroups were found to be present in the polymers. An equilibrium exists between hydroxymethyl endgroups and free formaldehyde as well as between final cyano groups and imidoester groups. Imidoester groups are shown to be formed only at cyano groups linked to hydrogen-substituted carbon atoms.     

Mechanismus der photopolymerisation des styrols, 1. Zur desaktivierung elektronisch angeregten styrols durch chemische konzentrations-löschprozesse: Photooligomere und photopolymere

Electronically excited styrene—in bulk or in concentrated solution—via intermolecular fluorescence self quenching processes undergoes a series of parallel and consecutive chemical reactions, leading to photooligomers and photopolymers. The oligomeric photoproducts, as shown by gas chromatography analysis, consist of dimers (M₂) and trimers (M₃) of styrene, whereby the quantity of M₂ exceeds M₃ by a factor of 20. The dimer fraction is built up of (a) 4 non olefinic cyclic C₁₆-hydrocarbons: cis-1,2-diphenylcyclobutane (c-CB, 45–50 wt.-%), trans-1,2-diphenylcyclobutane (tr-CB, 8–10 wt.-%), 1-phenyl-1,2,3,4-tetrahydronaphthalene (1-PhT, 7–9 wt.-%), and 2-phenyl-1,2,3,4-tetrahydronaphthalene (2-PhT, 3–5 wt.-%), (b) an open chain unsaturated compound–1-vinyl-2-(2-phenylethyl)benzene (VPEB, 5–7 wt.-%), and (c) 5 highly unsaturated mono-, bi-, and/or tricyclic C₁₆-valence isomers (19–32 wt.-%) which are considered to be the result of the participation of the aromatic benzene system in 1,2-, 1,3- or 1,4-photocycloaddition reactions, respectively. Among the numerous phototrimers, two saturated C₂₄-hydrocarbons were identified: 1-phenyl-4-(1-phenylethyl)-1,2,3,4-tetrahydronaphthalene (T₁) and 2-phenyl-4-(1-phenylethyl)-1,2,3,4-tetrahydronaphthalene (T₂). Under conditions where simultaneous thermal processes could be excluded (?20?T/°C?25), the presence of 1-PhT, 2-PhT, T₁ and T₂ gives strong evidence for the involvement of two 4π + 2π-photointermediates, viz. 1-phenyl-1,2,3,8a-tetrahydronaphthalene ( 1 ) and 2-phenyl-1,2,3,8a-tetrahydronaphthalene ( 1 ′), which undergo two consecutive reactions: (a) a unimolecular, photo-induced 1,3-sigmatropic rearrangement (1-PhT, 2-PhT) and (b) a bimolecular, photo-induced ene-reaction with styrene as enophilic component (T₁, T₂). Because of the non-concerted, stepwise nature of this photo-ene-process, the trimers have to be interpreted as the products of a cage reaction between two radical pairs |R₁…R₂| and |R₁…R₂′|. Their presence therefore gives strong evidence that the non-concerted ene-reaction is the most probable pathway for the production of the free radicals, which are responsible for the initiation of photopolymerization.     

Transduktion mit dem temperenten Proteus mirabilis-Phagen π1. I. Charakterisierung des Transduktionssystems

The influence of adsorption and multiplicities of infection on the transducing system Proteus mirabilis—π₁ was studied. The frequency of transduction and the rate of survival depended on the duration of the incubation of the transducing mixture. The maximum of transducing frequency was obtained after 5 min of incubation at 37 °C. This time corresponds to that required for optimal adsorption. The frequency of transduction and the rate of survival depended on the multiplicities of infection. An optimal frequency of transduction for the system studied was obtained with multiplicities of infection ranging from 4:1 to 8:1.     

Polymere mit dem Zentralatom eines makrocyclus in der hauptkette, 2. Polykondensationsreaktionen mit Germaniumkomplexen des Phthalocyanins und meso-Tetraphenylporphins

Dihydroxy(phthalocyanino)germanium ( 1b ) and Dihydroxy(tetraphenylporphino)germanium ( 3b ) react with different monovalent alcohols to afford low-molecular bisalkoxyderivatives ( 1c – f and 3c – h ). With bivalent alcohols and phenols polymers of the structure 5 and 6 or 8a, 9a and 8b, 9b , resp., are obtained. Dichloro(phthalocyanino)germanium ( 1a ) and Dichlor(tetraphenylporphino)germanium ( 3a ) react also with phenol, resp. hydroquinone, to give low-molecular and polymeric phenoxy-derivatives. The reaction of 1b and 3b with mono- and dibasic carboxylic acids leads to the corresponding esters. Dehydration of 3b gives polymeric porphin 15 . The IR-spectra of the prepared compounds are discussed and compared with the analogous complexes of hemiporphyrazingermanium. Thermogravimetric and semiconductive measurements (σ_298K = 10^?10 – 10^?15Ω^?1 cm^?1) are described.     

Einfluß verschiedener Initiatoren auf die Homo- und Copolymerisation des Trioxans

The hydride shift reaction occurring during the homo- and copolymerization of trioxane is influenced by the nature of the initiator used for the polymerization. Perchloric acid, boron trifluoride etherate, triphenylmethylhexafluoroarsenate and triethyloxoniumtetra-fluoroborate as initiators decrease the rate of the hydride shift reaction in comparison to molybdenylacetylacetonate and especially to tin tetrachloride. The transacetalization reaction is suppressed in favour of the propagation reaction when perchloric acid and molybdenylacetylacetonate are used as initiators; in these cases the dioxolane units are not statistically distributed over the polyoxymethylene chain. In comparison with these findings boron trifluoride and tin tetrachloride as initiators give statistical copolymers. Here the transacetalization reaction is not suppressed by the propagation reaction. By nuclear magnetic resonance investigations of trioxane-dioxolane copolymers it could be shown that the transacetalization, which leads to a connection of two dioxolane units, is suppressed in favour of all other possible transacetalization reactions.     

Synthesis of poly(phenyleneethynylene) without diine defects

Poly(phenyleneethynylene)s prepared by Pd/Cu-catalyzed synthesis contain diine defect structures. Diines are formed by reaction of Pd(II) species with ethynylides. The side reaction can be avoided by a low stationary state concentration of ethynylides. This can be achieved by a one pot reaction where removing of the trimethylsilyl groups and the polycondensation is simultaneously carried out. Deprotection is becoming the rate determining step, and thus the stationary state concentration of ethynyl compounds is low. A Cufree Pd catalyst is used. The absence of diines is shown in model reactions. An ester-containing poly(phenyleneethynylene) is prepared using the new technique. The polymer is amorphous, thermotropic, and lyotropic with a T_g of 41°C. It can be hydrolyzed to a polyelectrolyte with a rigid polymer backbone.     

Polymere mit dem Zentralatom eines Makrocyclus in der Hauptkette, 1. Polykondensationsreaktionen mit Phthalocyaninsilicium- und Hemiporphyrazingermanium-Verbindungen

Dihydroxy(phthalocyanino)silicon ( 1b ) and dihydroxy(hemiporphyrazino)germanium ( 2b ) react with different monovalent alcohols to afford low-molecular bisalkoxy derivatives ( 4 and 5 ), and with thiophenol the phenylthio derivatives 11a and 11b , resp. With bivalent alcohols and phenols polymers of the structure 6 and 7 or 8a, b, 9a, b , and 10a, b , resp. are obtained. Dichloro(phthalocyanino)silicon ( 1a ) and dichloro(hemiporphyrazino)germanium ( 2a ) react also with phenol, resp. hydroquinone, to give low-molecular and polymeric phenoxy derivatives. The reaction of 1b and 2b with mono- and dibasic carboxylic acids leads to the corresponding esters. The IR-spectra of the prepared compounds are discussed. Thermogravimetric and semiconductive measurements (σ_298K ≈ 10^?7 to 10^?16Ω^?1cm^?1) are described.     

Polykondensationen mit α-aminocarbonsäureestern. V. Kondensation des L-leucinäthylesters

The SnCl₄ catalyzed polycondensation of L-leucine ethyl ester is slower than the corresponding condensation of glycine ethyl ester, and leads to lower degrees of polymerisation, smaller yields, and to considerable amounts of the dioxopiperazine. A strong racemisation occurs in this reaction. Intermediately formed dioxopiperazine cannot be polymerized by SnCl₄ alone, but with α-aminocarbonic acid esters as cocatalysts polymerization takes place. Chloroform as a solvent has a strong influence on racemisation and yield of dioxopiperazine. In reactions without catalyst only racemization but no formation of oligopeptide esters or dioxopiperazine was observed. Mechanisms are presented for the catalyzed condensation polymerisation of the α-aminocarbonic acid esters, the ring opening polymerization of the dioxopiperazines, and the racemization.     

Polymere mit dem zentralatom eines makrocyclus in der hauptkette, 3.Polykondensationsreaktionen mit zinnkomplexen des meso-tetraphenylporphins,phthalocyanins und hemiporphyrazins

Dihydroxy(meso-tetraphenylporphino)tin ( 1b ), dihydroxy(phthalocyanino)tin ( 1d ), and dihydroxy(hemiporphyrazino)tin ( 1f ) react with bivalent phenols to afford polymers of type B . With 1,2-ethanediol and 1b low molecular compound 3 is obtained, which eliminates 1,2-ethanediol to give poly[oxyethyleneoxy(meso-tetraphenylporphin)stannandiyl] ( 4 ). Dehydration of the dihydroxy compounds 1b, 1d, 1f leads to polymers of type C . The IR-spectra of the prepared compounds are discussed; thermogravimetric and semiconductive measurements (σ_298K≈10^?6?10^?16Ω^?1cm^?1) are described and compared with the analogous complexes of germanium.     

Modification of isotactic poly(propylene) with a nitrogen plasma; differences in comparison to the treatment with a carbon dioxide plasma

The modification of isotactic poly(propylene) by nitrogen plasma treatment was studied in comparison to the use of a carbon dioxide plasma, which was reported earlier. The effect of the modification was characterized with secondary ion mass spectrometry (SIMS) to a depth of 3 Å, with electronic spectroscopy for chemical analysis (ESCA) to a depth of 20 Å and with attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to a depth of 10 μm: the nitrogen plasma modification seems to be milder than the CO₂ plasma treatment. Surface degradation is a minor reaction, and in an opposite manner, crosslinking and functionalization (formation of primary amino groups) are the most important reactions. Radicals, probably originating from the elimination of [methyl groups] along the polymer backbone, could induce these reactions.     

Lichtinitiierte polymer- und polymerisationsreaktionen, 10. Photoinduzierte zersetzung von diareniodonium- und triarensulfoniumsalzen durch kaliumtrisoxalatoferrat

In order to elucidate kinetics and mechanism of photoinitiation processes based on potassium trioxalatoferrate(III) (K₃[Fe(cx)₃])/ onium compounds/acrylamide (AA) interactions, photolysis and stationary photopolymerization were carried out. Diphenyliodonium chloride (Ph₂I^⊕Cl^?) and triphenylsulfonium tetrafluoroborate (Ph₃S^⊕BF^?₄) were used as onium compounds. These compunds react with photolytically formed ^˙ CO^?₂ radicals by an electron transfer mechanism. The resulting phenyl radicals were detected by spin trapping with nitrosodurene. The quantum yield of the decomposition of onium salts, ?_In, depends both on their reduction potentials and concentrations. Thus, an efficient redox reaction between ^˙ CO^?₂ radical and Ph₃S^⊕BF^?₄ is impossible because the former reacts faster with the Fe(III) complex. The ratio between rate constants of these competitive reactions (onium compound/Fe(III)) are 0,1 (Ph₂I^⊕Cl^?) and 4 · 10^?4 (Ph₃S^⊕BF^?₄). Only with the system K₃[Fe(ox)₃]/Ph₂I^⊕Cl^?/AA a radically induced photopolymerization was observed. Both the rate and the quantum yield (?_Br) depend on the Ph₂I^⊕Cl^? concentration. A correlation between ?_Br and √?_In was found.     

Thermodynamische verträglichkeit und wechselwirkungsparameter des systems oligoethylenglycol-oligopropylenglycol

The thermodynamics of the binary system oligo(ethylene glycol) (OEG) - oligo(propylene glycol) (OPG) is investigated by lightscattering. The Flory-Huggins interaction parameter χ₁₂ for this system is determined by the decrease of the OEG melting point in a mixture with OPG. At 310,8 K the system is compatible in the concentration range between 0 and 30 vol.-% of OPG in the mixture. The analysis of the temperature dependence of χ₁₂ according to the novel Flory theory leads to the assumption that mixing in this system occurs at a lower critical mixing temperature.     

Funktionsdiagnostik des Hypophysen-Schilddrüsensystems mit dem hypothalamischen Thyreotropin ausschüttendem Hormon (TRF) und dem Radiojod-Dreiphasenstudium

Zusammenfassung 1. Zur Aufstellung eines einfachen Untersuchungsschemas des Hypothalamo-Hypophysen-Schilddrüsensystems wurde die Dosis-Wirkungskurve peroral applizierten TSH-freisetzenden Hormones (TRH) im Radiojod-Dreiphasenstudium ermittelt.2. 10 mg TRF peroral bewirken bei etwa 30% gesunder Versuchspersonen einen deutlichen Anstieg der Radiojod-Aufnahme. 20 mg TRF peroral führt bei allen Versuchspersonen zu einem deutlichen Anstieg der Radiojod-Aufnahme, während das Gesamtthyroxin im Serum im Mittel sich nicht signifikant verändert. Nach 40 mg TRF peroral erfolgt der maximale Anstieg der Radiojod-Aufnahme. Nach 40 mg TRF peroral beginnt das Gesamtthyroxin im Serum etwas anzusteigen und erreicht den maximalen Anstieg nach etwa 140 mg.Diese Dosis-Wirkungsbeziehung ermöglicht neben der Messung der hypophysären TSH-Reserve eine getrennte Messung der thyreoidalen Jod-Aufnahme-Reserve und der Sekretionsreserve.3. Auf Grund dieser Ergebnisse wird folgendes Untersuchungsschema vorgeschlagen: Nach dem üblichen Radiojodstudium Applikation von 20 mg TRF peroral. Am nächsten Tag erneute Radiojod-Applikation und Messung der 2 h Radiojodaufnahme. Danach Applikation von 140 mg TRF peroral über 2 Tage und Messung des Gesamtthyroxins im Serum sowie der 48 h Radiojod-Aufnahme.4. Trijodthyroninbelastung (60 µg täglich über 14 Tage) bewirkt eine deutliche Hemmung des TRF-Effektes.5. Die Anwendungsmöglichkeiten dieser Untersuchung bei verschiedenen Störungen im Hypothalamus-Hypophysen-Schilddrüsensystem werden diskutiert.

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Hypophyseo-Thyroid system function test with thyrotropin-releasing-factor and the radioiodine-three-phase test

Summary The effect of orally administered thyrotropin-releasing-factor (TRF) on thyroid and hypophyseal function in the radioiodine-three-phase test was investigated in healthy volunteers. The following dose-effect relationship was found:(a) In only 30% of healthy controls did 10 mg TRF orally result in an increase of thyroidal radioiodine uptake.(6) 20 mg TRF results nearly always in a distinct increase of thyroidal radioiodine uptake, whereas the total serum thyroxine (T-4) remains unchanged. This increase of thyroidal radioiodine uptake is maximal after 80 mg TRF.(c) A signifikant increase of T-4 is measurable after 80 mg TRF. The elevation of T-4 is maximal after 140 mg TRF.These results show a dose related thyrotropin secretion due to TRF. Small doses have an effect on radioiodine uptake only, greater doses induce T-4 secretion too. This fact allows the selective testing of thyroidal uptake—and secretory reserve as well as measurement of hypophyseal sensitivity and thyrotropin reserve. Possible applications of TRF in the diagnostic of the hypothalamo-hypophyseo-thyreoideal system are discussed. The small dose and the maximal dose can be administered in one radioiodine test: after oral application of 20 mg TRF (at least 8 hours before investigation) measurement of the two hour radioiodine uptake, thereafter, further administration of 120 mg over two days and then measurement of 48 h radioidine uptake and analysis of serum thyroxine.

     

Der Stoffwechsel des menschlichen Herzens unter dem Einfluß von Insulin

Zusammenfassung Der Einfluß von Insulin bzw. Insulin und Glucose auf den Kohlenhydratstoffwechsel des menschlichen Herzens wurde an insgesamt 34 Patienten mit angeborenen und erworbenen Herzfehlern im Rahmen diagnostischer Herzkatheterisationen untersucht.Nach isolierter Insulinverabreichung (0,2 E/kg) lassen sich eine Abnahme der Glucosekonzentration sowie eine Steigerung des Lactat- und Pyruvatgehaltes im arteriallen Blut beobachten. Die arteriocoronarvenösen Differenzen, prozentualen Extraktionen und myokardialen Utilisationen dieser Substrate sowie deren Beteiligung am O₂-Verbrauch finden sich gegenüber dem Ausgangswert deutlich erhöht.Unter dem Einfluß von Insulin (0,1 E/kg) und Glucose (1 g/min) steigt der Blutzuckergehalt auf das Doppelte des Ausgangswertes an. Die arteriellen Konzentrationen von Lactat und Pyruvat zeigen ein ähnliches Verhalten wie nach isolierter Insulinverabreichung. Sowohl 20 als auch 30 min nach Infusionsbeginn sind Aufnahme, Verbrauch und O₂-Extraktionsquotient aller Kohlenhydrate deutlicher erhöht als nach alleiniger Insulingabe.Der Anteil aller Kohlenhydrate am myokardialen O₂-Verbrauch, der normalerweise bei etwa 35% liegt, erfährt nach isolierter Insulinverabreichung eine Steigerung auf mehr als das Doppelte und bei kombinierter Insulin-Glucoseeinwirkung auf annähernd das Vierfache.Somit führt Insulin nicht nur in der Peripherie, sondern auch am Herzen zu einer bedeutenden Zunahme der Kohlenhydrataufnahme und -verwertung. Dabei werden Lactat und Pyruvat weitgehend in Relation zum arteriellen Angebot extrahiert, während dieses für Glucose keine Bedeutung hat. Der Herzmuskel stellt sich aber nicht auf reine Kohlenhydratverwertung um, wie der respiratorische Quotient unter 1 beweist. Da der Anteil der Kohlenhydrate am O₂-Verbrauch stärker zunimmt, als es dem respiratorischen Quotienten entspricht, und der Gesamtsauerstoffextraktionsquotient über 100% anwächst, müssen im Herzmuskel unter dem Einfluß von Insulin Speicherungsvorgänge stattfinden. Diese werden ebenso wie der oxydative Abbau der Kohlenhydrate noch intensiviert, wenn mit Insulin gleichzeitig Glucose gegeben wird, da die Insulinwirkung bei erhöhtem Blutzucker keine Beeinträchtigung durch reaktiv ausgeschüttetes Adrenalin erfährt.

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Summary The effects of insulin and of insulin combined with glucose on the carbohydrate metabolism were determined during diagnostic heart catheterisations in a total of 34 patients with congenital and acquired heart diseases.Following isolated insulin administration (0.2 U/kg) a diminution of glucose concentration and a rise in lactate and pyruvate content of the arterial blood are observed. The arterio-coronaryvenous difference, the percentual extraction, the myocardial utilisation and the O₂-extraction ratios of the substrates show a marked elevation from initial levels.Under the influence of insulin (0.1 U/kg) and glucose (1 g/min) the blood sugar rises to double levels. The arterial concentrations of lactate and pyruvate show reactions similar to those found following isolated insulin administration. Twenty and thirty minutes after the infusions have started the uptake, utilisation and oxygen extraction ratio of all carbohydrates are more distinctly increased than after insulin application alone.The myocardial oxygen extraction ratio of all carbohydrates which is normally about 35 per cent more than doubles after isolated insulin administration and rises to nearly four times the initial levels under combined insulin-glucose influence.Insulin thus causes a marked rise of carbohydrate uptake and utilisation not only in the periphery but also in the myocardium. The myocardial lactate and pyruvate extraction depends mainly on the arterial concentration whereas the glucose uptake is not relative to the arterial blood sugar content. The heart muscle, however, does not adjust to sole carbohydrate usage, as reflected by a respiratory quotient below one. The disproportionately high oxygen extraction ratio of carbohydrates in relation to the respiratory quotient and an oxygen extraction ratio of all substrates over 100 per cent indicate that storage of substrates must take place in the myocardium under the influence of insulin. This storage and the oxydative degradation of carbohydrates are further intensified when glucose and insulin are administered simultaneously because due to the raised blood sugar the action of insulin is not inhibited by reactive adrenalin secretion.

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Herrn Prof. Dr. Dr.G. Bodechtel zum 70. Geburtstag.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Zur Bedeutung des Proteasen-Inhibitors des Säugerspermas bei der Befruchtung und zur Frage der Identität mit dem Dekapazitationsfaktor

Zusammenfassung Ein aus Kaninchensperma isoliertes trypsinähnliches Enzym, das {ie826-1}-Benzoyl-DL-arginin-p-nitroanilid und denaturiertes Hämoglobin spaltet, ist durch den von uns aus menschlichem Sperma isolierten Trypsin-Plasmin-Inhibitor hemmbar. Das Spermaenzym vermag die Corona radiata und die Zona pellucida von Kanincheneizellen aufzulösen. Dieser Vorgang kann durch den Proteinase-Inhibitor aus menschlichem Spermaplasma verhindert werden.Die Frage, ob der Proteasehemmstoff aus Spermaplasma mit dem sog. Dekapazitationsfaktor identisch ist, wird diskutiert.

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Summary A trypsinlike enzyme isolated by us out of rabbitssperm splits {ie826-2}-benzoyl arginine-DL-p-nitroanilide and denaturated hemoglobin. This enzyme is inhibited by an inhibitor for trypsin and plasmin which was isolated by us out of human sperma plasma. This enzyme is able to destroy the corona radiata and the zona pellucida of the ovum of rabbits. These reactions are inhibited by the proteinase inhibitor of sperma plasma of man.The question if the proteinase inhibitor is identical with the decapacitation factor is discussed.

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Vorgetragen auf dem VII. Int. Congress of Clinical Chemistry Genf am 12. 9. 69.     

Studies on organometallic compounds as polymerization catalysts. II. Diethylzinc/water system for epoxide polymerization

Diethylzinc/water system was studied using infrared spectroscopy, X-ray diffraction, and vapor phase chromatography. The main reactions of diethylzinc with water are considered to be as follows: Relative LEWIS acidity for ether is found to be in the order: Initiators for the polymerization of propylene oxide by diethylzinc/water system are found to be Et(ZnO)_nZnEt, Et(ZnO)_nH, or HO(ZnO)_nH, which have disordered wurtzite structures concerning zinc-oxygen bond. On the hydrolysis of the polymerization system, 2-methyl-l-butanol, 2-pentanol, and propylene glycol are found as initial products. The main reaction of the polymerization of propylene oxide catalyzed by diethylzinc/water system was discussed in terms of the coordinate ionic mechanism.