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Intraalveolar fibrin formation is a hallmark of many acute and chronic lung inflammatory processes. We investigated the influence of fibrin polymerization on biochemical and biophysical properties of a calf lung surfactant extract (CLSE) used for therapy of neonatal distress syndrome. Thrombin-induced coagulation of human fibrinogen (range, 0.04 to 4 mg/ml) in the presence of CLSE (2 mg/ml phospholipids) resulted in progressive loss of surface tension-lowering properties and adsorption facilities of this surfactant preparation; the CLSE-inhibitory capacity of desAABB-fibrin surpassed that of fibrinogen by more than two orders of magnitude. In parallel with the loss of surface activity, association of the predominant surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) (14C-labeled, admixed to 2 mg/ml CLSE) with polymerizing desAABB-fibrin occurred. A volume of 0.3 mg/ml insoluble fibrin effected a approximately 50% loss, and 0.6 mg/ml a > 90% loss, of DPPC from the aqueous phase. Dioleoylphosphatidylcholine, dipalmitoylphosphatidic acid, stearic acid, palmitic acid, and arachidonic acid, admixed to CLSE as labeled compounds, as well as total CLSE phospholipids were retained in polymerizing desAABB-fibrin with dose-effect curves superimposable to that of DPPC; no fibrin association was noted for 14C-glycerol-3-phosphate. Polymerizing desAA-fibrin, generated by incubation of CLSE-fibrinogen mixtures with arvin, captured DPPC and resulted in loss of surface properties at even lower concentrations, compared with desAABB-fibrin. In contrast, CLSE incubation with preformed desAABB- and desAA-fibrin polymers did not cause substantial phospholipid coupling with the clot material or loss of surface properties. Microtiter plate-immobilized fibrinogen and desAABB- and desAA-fibrinomonomers did not bind CLSE phospholipids enriched with 14C-DPPC.(ABSTRACT TRUNCATED AT 250 WORDS)

SocietC suisse de chimie, BPle -Societa svizzera di chimica, Basilea Nachdruck verboten -Tous droits reserves -Printed by Birkhauser AG., Basel, Switzerland Erscheint 9mal jahrlich -Parait 9 fois par an Summary Chiral derivatives of the complexing 1 , 2-diheterosubstituted ethanes A-D are prepared from tartaric acid. The key starting materials are the succinic acid derivative 1, the dioxolane 2a, and the diamide 3a. These are converted to the ethers, alkoxyamines, and alkylthio-amines listed in the first column of Table 2 which also contains the derivatives 21c, 22d, and 23d made from lactic acid, malic acid, and proline, respectivelly. It is shown that the highest optical yields (up to 40%) in reactions of butyllithiam with aldehydes are obtained when mixtures of (-)-1 ,2,3,4-tetramethoxybutane (4b), ( +)-2,3-dimethoxy-N, N , N', N'-tetramethyl-l,4-butanediamine (17 a), and (-)-1 ,4-dimethoxy-N, N , N', N'-tetramethyl-2,3-butanediamine (14c) with pentane are used at temperatures down to -150" and ratios of auxiliary/butyllithium of up to 10: 1 (gee equation (l), Tables 2 4 ) .Seit elnigen Jahren beschaftigen wir uns [l-41 mit der durch nicht kovalente Wechselwirkungen zwischen Hilfsstoff und Reaktanden verursachten, bisher kaum untersuchlten [5], asymmetrischen Synthese. Hierfur mussen die Hilfsstoffe in grosseren Mengen einfach herstellbar, moglichst in beiden enantiomeren Formen zuganglich und leicht zuriickgewinnbar sein. Als Vorlaufer bietet sich daher Weinsaure an. Aus ihr sowie aus Milchsaure, Apfelsaure und Prolin haben wir eine Reihe von Polyathern, Alkoxyaminen und Thioathern hergestellt. Sie leiten sich alle von 1,2-diheterosubstituierten Athanen A-D ab. Von diesen haben sich Dimethoxyathan (Glyme, A) und N, N, N', N'-Tetramethylathylendiamin (B) als Losungs-[6] und Komplexierungs-1) 31a Teilweise aus den geplanten Dissertationen von G. Crass, W. Langer, H.-A. Oei und M . Schmidt, Universitat Giessen. 302 HELVETICA CHIMICA ACTA -Vol. 60, Fasc. 2 (1977) -Nr. 35 R mittel [7] in der metallorganischen Synthese bewahrt, so dass zu erwarten war, dass mit chiralen Komplexen E enantioselektive Synthesen moglich sind. Wir beschreiben hier zunachst die Herstellung der Hilfsstoffe nach Verfahren, die zum Teil aus jahrelangen Erfahrungen resultieren, sowie Induktionsversuche bei der Addition von Butyllithium an Aldehyde. Viele der erhaltenen Zwischenstufen sind auch als Ausgangsprodukte fur den Aufbau von optisch reinen Naturstoffen und pharmakologisch aktiven Verbindungen [8-101 sowie zur Herstellung von chiral modifiziertem Lithiumaluminiumhydrid [8] [9] [l 11 interessant. In allen folgenden Formeln sind die Konfigurationen der aus der naturlichen ( R , R)-( + )-Weinsaure erhaltenen Produkte angegeben; wenn wir auch das Enantiomere herstellten, finden sich entsprechende Hinweise im exper. Teil. A. Herstellung der Hilfsstoffe. -Wir gingen von den drei Weinsaurederivaten 1-3 aus. 1 erhielt man durch Veratherung (NaH/(CH30)2S02) von Weinsaureester [12], wofur wir eine racemisierungsfreie, einfache, ungefahrliche D...

Attempts to deprotonate nitrocyclopropane led to solutions which showed strong ESR. signals (Fig. 1)and from which 1‐nitro‐ l′‐nitroso‐bicyclopropyl (3) and 1,1′‐dinitro‐bicyclopropyl (2) were isolated. The activation energy for rotation about the central C, C‐bond of 2 is estimated to be about 12 kcal/mol (1 H‐NMR. spectra in Fig. 2). In contrast, the oven‐chain analogue 2,3‐dimethyl‐2,3‐dinitrobutane (1) shows a methyl singlet down to −70° C. Low‐temperature X‐ray analyses of 1, 2, 3, and also of 1,1′‐dinitro‐bicyclobutyl (4) show that all four molecules have gauche‐conformations but reveal striking structural differences between the openchain and the cyclic derivatives (Fig. 4–6): the central C, C‐bond is long in 1 (1.575 Å), short in 2 (1.479 Å); the C, N‐bonds are long in 1 (1.549 Å), short in 2 (1.488 Å); the orientation of the nitro groups is bisected in 2 and perpendicular in 1. The crystal structure of the nitro‐nitroso compound 3 is isomorphous with that of the dinitro compound 2 and thus disordered (Fig. 15–16). The effect of the nitro group as π‐electron acceptor on the molecular conformations and bond lengths is discussed. From analysis of the anisotropic vibrational parameters of 2 the root‐mean‐square librational amplitude of the nitro groups about their C, N‐bonds is estimated to be about 5.8° at 95 K, corresponding to a rotational barrier of about 9 kcal/mol, i. e. the same order of magnitude as the NMR. estimate of about 12 kcal/mol for C, C‐rotation.