The aim of this study was to examine whether extreme endurance stress of trained athletes can influence lipid peroxidation and muscle enzymes. A randomized and placebo-controlled study was carried out on 24 trained long-distance runners who were substituted with alpha-tocopherol (400 I.U. d-1) and ascorbic acid (200 mg d-1) during 4.5 weeks prior to a marathon race. The serum concentrations of retinol, ascorbic acid, beta-carotene, alpha-tocopherol, malondialdehyde (TBARS) and uric acid as well as glutathione peroxidase (GSH Px) and catalase were measured 4.5 weeks before (A), immediately before (B), immediately after (C) and 24 h after (D) the course. After competition (C) TBARS serum concentrations of the athletes (n = 22) decreased in both groups (P < 0.0001). The ascorbic acid serum concentration increased significantly in the supplemented group from (A) to (B) (P < 0.01), from (B) to (C) (P < 0.001) and in the placebo group a significant increase from (B) to (C) (P < 0.01) was observed. The alpha-tocopherol serum concentration increased significantly in the supplemented group from (A) to (B) (P < 0.001) and from (B) to (C) (P < 0.05). The enzymes glutathione peroxidase (GSH Px) and catalase measured in erythrocytes as well as the serum selenium levels did not show significant differences at any time. A significant increase of CK concentration was observed from (C) to (D) in the supplemented group (P < 0.01) and in the placebo group (P < 0.001). The increase of CK serum concentration is remarkably lower in the supplemented group compared with the placebo group (P < 0.01). It is concluded that endurance training coupled with antioxidant vitamin supplementation reduces blood CK increase under exercise stress.

This study was undertaken to evaluate the effects of 5 months of α-tocopherol supplementation on physical performance during aerobic exercise training in 30 top-class cyclists. Antioxidative effects of supplementation were also studied. Plasma α-tocopherol concentration increased significantly in the vitamin E-supplemented group, whereas the placebo group showed a trend toward decrease. Physical performance did not improve in the α-tocopherol-supplemented group compared to the placebo group. Heart rates were also not significantly different. Lactate concentrations at the aerobic threshold and the anaerobic threshold were identical. Thus, there was no performance improvement in the α-tocopherol-supplemented group. However there was a significant reduction in CK in serum of the E-supplemented group. A trend toward decrease in GOT, GPT, and LDH was observed with α-tocopherol supplementation. Moreover, significantly reduced malondialdehyde serum levels were measured in the E-supplemented group. The findings indicate a protective effect of α-tocopherol supplementation against oxidative stress induced by strenuous exercise.

No abstract

Die 'H-und 3C-Kernresonanz-Spektren eines [2]-Catenans (1) und seiner molekularen Untereinheiten (2, 3) wurden in CDCI3, C6Db und C6Dlz gemessen. Im 13C-NMR-Spektrum beobachtet man beim ubergang von den molekularen Untereinheiten zum Catenan Tieffeldverschiebungen von bis zu 1 ppm, die mit van der Waals-Wechselwirkungen zwischen den beiden Untereinheiten erklart werden konnen. Im 'H-NMR-Spektrum findet man sowohl Hochfeldals auch Tieffeldverschiebungen, die in erster Linie durch Losungsmitteleffekte hervorgerufen werden. Die Spektren der Cycloalkane von C6H12 bis C44H88 werden zum Vergleich in Abhangigkeit von der Ringgrok diskutiert. Comparative N. M. R. Studies on Macrocycles and on a CatenaneThe 'H and 13C n.m.r. spectra of a [2]-catenane (1) and its molecular subunits (2,3) were measured in CDCI,, Cb&, and C6D12. In the I3C n.m.r. spectrum low field shifts of up to 1 ppm are noted in going from the molecular subunits to the catenane. These can be explained by van der Waals interactions between the two subunits. In the 'H n.m.r. spectrum high field as well as low field shifts can be observed which are mainly caused by solvent effects. For comparison the spectra of the cycloalkanes from C6HI2 up to C44Hs8 are discussed as a function of ringsize.

Bei der Cyclisierung der Verbindung 15 sind die vier monomeren, vierfach iiberbriickten 5,6-Diamino-l,3-benzodioxol-Derivate 16 -19 zu erwarten. Ausgehend von Verbindung 3 wird in einer neunstufigen Reaktionsfolge 15 synthetisiert. Seine Cyclisierung in Isoamylalkohol in Gegenwart von Natriumcarbonat und Natriumiodid unter Verdiinnungsbedingungen ergab drei isomere Cyclisierungsprodukte in einer Gesamtausbeute von 1.7%. Ihre Konstitution wird anhand der Massenspektren sowie von 13C-und 'H-NMR-Spektren diskutiert.Studies on the Synthesis of Molecules with Knot Structure Fourfold Bridged 5,6-Diamino-1,3-benzodioxole Derivatives By cyclization of compound 15 the four monomeric fourfold bridged 5,6-diamino-l,3benzodioxole derivatives 16-19 are to be expected. Starting with compound 3 the diaminoacetal 15 is synthesized in a nine-ship reaction sequence. Its cyclization in isoamyl alcohol in the presence of sodium carbonate and sodium iodide under high dilution conditions afforded three isomeric cyclization products in a total yield of 1.7%. The structure of the cyclization products, based on mass spectra, I3C-and ' H NMR spectra, is discussed.Verbindungen mit Knotenstruktur sind rnit einfachen Makrocyclen topologisch isomer, wenn sie identisch sind hinsichtlich der Art, Anzahl und Reihenfolge ihrer Atome. Die Synthese verknoteter Verbindungen ist von Interesse, weil an diesen Verbindungen intramolekulare Wechselwirkungen zwischen Molekiilketten und die Abhangigkeit der physikalischen Eigenschaften einer Verbindung von der Topologie untersucht werden konnen. In jiingster Zeit konnten Wung und Mitarbb. zeigen, daI3 sich aus einstrangiger cyclischer Phagen-DNA durch Behandlung mit Escherichiu coli-o-Protein Verbindungen mit Knotenstrukturen bilden.Die bisher gemachten Vorschlage zur Synthese von Verbindungen mit Knotenstruktur haben wir in einer friiheren Publikation zusammengefaRt2). In einern von uns entworfenen Konzept3) zur Synthese einer Verbindung mit der Struktur eines dreiblattrigen Knotens kommt einem vierfach iiberbriickten 5,6-Diarnino-l,3-benzodioxol-Derivat der Struktur 18, dern ,,Prlknoten", eine Schliisselrolle zu. Aus dieser Verbindung sollte nach Spalten der Acetalbindungen und der Bindungen zwischen dem aromatischen Kern und den beiden Stickstoffatomen ein dreiblattriger Knoten entstehen.Die Synthese des Prtiknotens 18 erscheint moglich durch Cyclisieren eines zweifach iiberbriickten 5,6-Diamino-l,3-benzodioxols 1 unter Verdiinnungsbedingungen. Hierbei sollten neben 18 noch zwei strukturell bzw. topologisch isomere Verbindungen des Typs 16 und 17 entstehen ').