From the CH(2)Cl(2) extract of the sponge Hyrtios cf. erecta, collected from Fiji, two new sesterterpenes, 1 and 2, and the known compounds isodehydroluffariellolide (3), homofascaplysin A (4), and fascaplysin (5) were isolated. The structures of 1-5 were established employing 1D and 2D NMR spectroscopy and mass spectrometry. All NMR resonances of fascaplysin (5) have been unambiguously assigned. Evaluation of the biological activity of the extracts and pure compounds toward Plasmodium falciparum, Trypanosoma brucei subsp. rhodesiense, Trypanosoma cruzi, hepatitis A virus (HAV), several other microbial targets, and HIV-1-RT and p56(lck) tyrosine kinase revealed new activities for homofascaplysin (4) and fascaplysin (5), both being potently active in vitro against P. falciparum.

ZUSAMMENFASSUNG :Bei der Kristallisation orientierter Schmelzen &us isotaktischem Polypropylen erhiilt man Bandspharolithe, die uberwiegend aus 8-Modifikation bestehen, wenn die Kristallisationstemperatur im Bereich von 100 bis 130°C liegt. Dabei ist es gleichgiiltig, auf welche Weise die Orientierung erzeugt wird. Der Anteil der Bandspharolithe am kristallisierenden Material ist um so groBer, je starker die Schmelze orientiert wurde.Der Gehalt an 8-Modifikation in den Bandsphgrolithen ist um so groaer, je hoher die Orientierung der Schmelze ist und je schneller die Schmelze auf die Kristallisationstemperatur abgekiihlt wird. Auf Grund der um ca. 35% hoheren Wachstumsgeschwindigkeit der 8-Modifikation geniigt eine relativ geringe Anzahl von 8-Keimen in der Achse der Bandspharolithe, um uberwiegend aus 8-Modiiikation bestehende Bandsphgrolithe zu erhalten. SUMMARY :Crystallization of oriented melts of isotactic polypropylene yields row spherulites consisting mainly of the 8-modification, if crystallization temperature is in the range between 100 and 130 "C. This does not depend on the way by which orientation has been achieved. The amount of row spherulites in the crystallizing material parallels with increasing orientation of the melt.The row spherulites contain increasing amounts of 8-form, if the orientation of the melt and the cooling rate from melt to crystallization temperature are increased. Based on the observation that the rate of crystallization is approximately 35% faster for the 8-form, only a relative small number of @-nuclei in the axis of the row spherulites is necessary to produce row spherulites, which consist mainly of the 8-modification. Einleitung

Methods have been developed for the preparation of terminal p-idophenyl-substituted alpha- and beta-methyl-branched long-chain fatty acids. The syntheses and physical properties of 14-(p-iodophenyl)-2(RS)-methyltetradecanoic acid and 15-p-iodophenyl)-3(RS)-methylpentadecanoic acid are described. The radioiodinated agents are of interest as a result of the expected pronounced uptake and prolonged myocardial retention that may result from the inhibition of fatty acid metabolism. Tissue distribution studies in rats with 14-(p-[125I]iodophenyl)-2(RS)-methyltetradecanoic acid and 15-(p-[125I]iodophenyl)-3(RS)-methylpentadecanoic acid show significant heart uptake and prolonged retention accompanied by low in vivo deiodination and high blood levels. A comparison of the heart uptake of the radioiodinated methyl-branched fatty acids and their unbranched analogues has demonstrated a greater myocardial retention of the methyl-branched fatty acids than the unbranched analogues. These results suggest that the mechanism of myocardial retention results from steric or chemical inhibition of the metabolism of these fatty acids by the presence of the methyl group.

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In memory of the late Professor Oskar E. Polansky Phosphorescence in ethanol and n-pentane at 77 K of the benzologues 1-8 of furan, thiophene, selenophene and tellurophene has been investigated. The rate constants of both the radiative (A .PT) and non-radiative (A :GT) deactivation of the lowest triplet state correlate linearly with X cl C2 where ck denotes the Hückel AO coefficients in the HOMO of the carbon atoms bound to the hetero-atom and ( is the spin-orbit coupling constant of the hetero-atom present. -The linear correlation observed between A .PT and kGT is an example for the Orlandi-Siebrand rule. -The influence of an external heavy-atom perturber (methyl iodide) on phosphorescence lifetimes and the vibrational structure of phosphorescence spectra is the more efficient the less efficient is the internal perturbation caused by the intra-annular heavy-atom.