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1.
Zusammenfassung Für die Elemente Neon, Natrium, Magnesium, Aluminium und Silizium werden mit einem quantenmechanischen Variationsverfahren unter Verwendung einer minimalen STF-Funktionenbasis Röntgenübergänge vom Typ K 1L1L2 berechnet und den K -Satellit-Linien , , 3, 3 and 4 zugeordnet.
Relation between K -Satellits and X-ray-transitions of the type K 1 L 1L 2 for Ne, Na, Mg, Al and Si
STF-Calculations are reported for X-ray-transitions of the type K 1L1L2 for Ne, Na, Mg, Al and Si. It is shown that these transitions are correlated with the K -satellits , , 3, 3 and 4.


Die Wellenfunktionen können auf Anfrage zur Verfügung gestellt werden.  相似文献   

2.
Whereas 1 1 crystalline complexes have been isolated between borane ammonia and methyl 4,6-O-benzylidene-2,3-dideoxy--d-galactopyranosido [2,3-b]-1,4,7,10,13,16-hexaoxacyclo-octadecane (1), methyl 4,6-O-benzylidene-2,3-dideoxy--d-mannopyranosido [2,3-b] (methyl 4,6-O-benzylidene-2,3-dideoxy--d-mannopyranosido [2,3-k]-1,4,7,10,13,16-hexaoxacyclo-octadecane (3), and (1R,2R,7R,24R)-3,5,8,11,14,17,20,23,26,28-decaoxatricyclo-[21.4.0.02,7]octacosane (4), the hosts, methyl, 4,6-O-benzylidene-2,3-dideoxy--d-mannopyranosido[2,3-b] 1,4,7,10,13,16-hexaoxacyclo-octadecane (2) and 1,4 1,4 3,6 3,6-tetra-anhydro-2,2 5,5-bis-O-oxydiethylenedi-d-mannitol (5) have yielded 2 1 (guest:host) crystalline complexes with borane ammonia as guest. X-ray analyses of the supramolecular structures of BH3NH3 ·1, (BH3NH3)2 ·2, BH3NH3 ·3, BH3NH3 ·4, and (BH3NH3)2 ·5 have been carried out and BH3NH3 ·1, BH3NH3 ·2, and (BH3NH3)2 ·5 have been shown to reduce acetophenone with enantiomeric excesses of 5, 13, and 10% respectively. Supplementary Data relating to this article (atomic coordinates of the hydrogen atoms and thermal parameters) are deposited with the British Library as Supplementary Publication No. SUP 82017 (74 pages).Dedicated to Professor H. M. Powell.  相似文献   

3.
Zusammenfassung Von den synthetischen Ketosiden der N-Acetyl-d-neuraminsäure werden nur die weniger stark linksdrehenden, als -Ketoside bezeichneten Anomeren durch die Neuraminidasen vonVibrio cholerae und Influenzavirus hydrolysiert. Die Natur des -ketosidisch gebundenen Restes ist für die Spaltbarkeit von untergeordneter Bedeutung. DieMichaelis-Konstanten für die enzymatische Hydrolyse von 2-Alkyl- und 2-Aralkyl-N-acetyl--d-neuraminsäuren liegen ebenso wie für die des natürlich vorkommenden Trisaccharides N-Acetylneuraminyl-lactose in der Größenordnung von 10–3 m. Für quantitative bestimmungen der enzymatischen Wirksamkeit von Neuraminidase-Präparaten ist die gut kristallisierende und rasch spaltbare 2-m-Nitrobenzyl-N-acetyl--d-neuraminsäure besonders geeignet. -Ketoside der N-Glykolyl-d-neuraminsäure werden vonV. cholerae-Neuraminidase ebenfalls, wenn auch langsamer, hydrolysiert. Die Methylester der -Methyl-ketoside von N-Acetyl- und N-Glykolyl-d-neuraminsäure sind enzymatisch nicht spaltbar.
Among the synthetic ketosides of N-acetyl-d-neuraminic acid only the less levorotatory anomers, which have been designated as the -ketosides, are hydrolyzed by the neuraminidase ofVibrio cholerae and influenza virus. The -ketosides are prone to be cleaved by the neuraminidase irrespective of the nature of their aglycon. TheMichaelis constants have been determined for the enzymatic hydrolysis of several 2-alkyl and 2-aralkyl N-acetyl-d-neuraminic acids as well as for the cleavage of the naturally occurring trisaccharide, N-acetylneuraminyl-lactose, and have been found to be of the order of 10–3 m. The crystalline and readily hydrolyzable substrate, 2-m-nitrobenzyl-N-acetyl--d-neuraminic acid, has proved to be particularly suited for quantitative estimations of the enzymatic activity of neuraminidase preparations. -Ketosides of N-glycolyl-d-neuraminic acid are also cleaved byV. cholerae neuraminidase, though somewhat more slowly. The methyl esters of the methyl ketosides of N-acetyl and N-glycolyl--d-neuraminic acid are resistant to neuraminidase.


Mit 7 Abbildungen  相似文献   

4.
Zusammenfassung Es wird über die Synthese von N-(-Aminoacyl)-p-toluolsulfonamiden und N-(-Aminoacyl)-methansulfonamiden berichtet, deren Acylreste sich vonl-Tyrosin,d,l--Methyl-tyrosin undd,l-3,4-Dihydroxy-phenylalanin ableiten.
The synthesis of N-(-aminoacyl)-p-toluenesulfonamides and N-(-aminoacyl)-methanesulfonamides containing the acyl groups ofl-tyrosine,d,l--methyltyrosine andd,l-3,4-dihydroxy-phenylalanine is described.
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5.
Zusammenfassung Aus Mono-und Dihalogen-essigsäuren bilden sich mitSchiff-schen Basen in Dimethylformamid (DMF) und POCl3 (bzw. POBr3) über labile Addukte -Lactame. Analog reagieren -Chlor-und -Brom-propionsäure.
The reaction of -chloro and -bromo acetic or propionic acids withSchiff bases inDMF in the presence of POCl3 or POBr3 yields -lactames via unstable adducts.
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6.
Five new sulfated derivatives of sokotrasterol and halistanol have been obtained: 24-nor-5-cholane-2,3,6,23-tetraol 2,3,6-tri(sodium sulfate); 24-nor-5-cholane-2,3,6,23-tetraol 2,3,6-tri(sodium sulfate) 23-palmitate; 24,25-dimethyl-5-cholestane-2,3,6-triol 3-(sodium sulfate); 24,25-dimethyl-5-cholestane-2,3,6-triol 6-(sodium sulfate); and 24,25-dimethyl-5-cholestane-2,3,6-triol 2,6-di(sodium sulfate). The inhibiting and membranolytic properties of the polysulfated steroids from sponges and their derivatives have been studied. It has been shown that physiological activity in this series of compounds depends on biphilicity.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 441–445, July–August, 1986.  相似文献   

7.
Zusammenfassung -Äthyl--phenylacetessigester (I) wurde bromiert, der resultierende -Bromacetylphenylbuttersäureester (II) mit NaBH4 zum Bromhydrin (III) reduziert. Umsetzung mit KCN lieferte den -Cyan--hydroxy--phenyl--äthylbuttersäureester (IV), der in Gegenwart vonRaney-Ni zu den beiden stereoisomeren 3-Äthyl-3-phenyl-4-hydroxypiperidonen-(2) (Va) und (Vb) reduziert wurde. Oxydation von (Vb) mit CrO3 lieferte das 3-Äthyl-3-phenylpiperidindion-(2,4) (VI).  相似文献   

8.
New 1,3-dioxanes, which are derivatives of 2-nitro-2-ethylpropane-1,3-diol and aldehydes of the furan series, were synthesized. The nitrodioxanes were reduced by means of sodium amalgam to the corresponding amines. The kinetics of the formation of the nitrodioxanes was studied. The accelerating action of the electron-acceptor diol substituent on the reaction rate was established. The rate constants in the aldehyde series increase on passing from-methylfurfural to-nitrofurfural, and they correlate satisfactorily with Brown's p + constants.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1159–1162, September, 1972  相似文献   

9.
N1-(-Tetrahydrofuranyl)- and N1-(-tetrahydropyranyl)uracils and the corresponding 6-azauracils have been obtained by the condensation of bistrimethylsilyl derivatives of uracils and 6-azauracils with-chlorotetrahydrofuran and-chlorotetrahydropyran. The superiority of the silyl method over the mercury method used previously has been demonstrated.For part III, see [9].  相似文献   

10.
The action of N-methylpiperazine and , -dimethylpyrrolidine on chloroacetyl derivatives of phenylhydrazides of diaryl- and dialkylglycolic acids has given the previously unknown N-methylpiperazinoacetyl and , -dimethylpyrrolidnoacetyl derivatives of these phenylhydrazides.For part XL, see [1].  相似文献   

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