Aminoacyl derivatives of nucleosides, nucleotides, and polynucleotides Communication 12. Synthesis of 3?(2?)-O-L-aminoacylnucleotides without prior protection of the amino group

Author(s):  
B. P. Gottikh ◽  
A. A. Kraevskii ◽  
P. P. Purygin
Keyword(s):  

1974 ◽  
Vol 10 (5) ◽  
pp. 538-540
Author(s):  
T. �. Bezmenova ◽  
P. G. Dul'nev


Author(s):  
M. I. Dagene ◽  
L. P. Rasteikene ◽  
O. V. Kil'disheva ◽  
I. L. Knunyants


1992 ◽  
Vol 57 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.



1982 ◽  
Vol 203 (2) ◽  
pp. 427-433 ◽  
Author(s):  
N UI ◽  
C Takasaki ◽  
N Tamiya

The isoelectric points of erabutoxins a, b and c, neurotoxic proteins of a sea snake, Laticauda semifasciata, were determined by density-gradient isoelectric focusing. The same measurement was also made with monoacyl derivatives of erabutoxin b, in which each one of all amino groups had been either acetylated or propionylated. Erabutoxins a and b showed the same isoelectric point at pH 9.68. The values for [1-N alpha-acetyl-arginine]-, [15-N6-acetyl-lysine]-, [27-N6-acetyl-lysine]-, [47-N6-propionyl-lysine]- and [51-N6-acetyl-lysine]-erabutoxin b were at pH 9.52, 9.31, 9.45, 9.22 and 9.09 respectively, being definitely different from each other and lower than the value for the unmodified molecule. The isoelectric point of erabutoxin c, which is [51-asparagine]-erabutoxin b, was the same as that of [51-N6-acetyl-lysine]erabutoxin b. Assuming that no change in pK occurs on monoacylation, the pK values of amino groups in erabutoxin b were calculated from the isoelectric-point data. It is indicated that the pK values of zeta-amino groups differ markedly from each other and that the value of alpha-amino group is anomalously high.



2006 ◽  
Vol 49 (20) ◽  
pp. 6104-6110 ◽  
Author(s):  
David Rennison ◽  
Humphrey Moynihan ◽  
John R. Traynor ◽  
John W. Lewis ◽  
Stephen M. Husbands


1960 ◽  
Vol 38 (7) ◽  
pp. 1135-1140 ◽  
Author(s):  
I. Levi ◽  
A. E. Koller ◽  
G. Laflamme ◽  
J. W. R. Weed

The N-dichloroacetyl derivatives of DL-serine and DL-threonine were prepared by the Schotten–Baumann reaction from the amino acids and dichloroacetyl chloride. Negative ninhydrin tests coupled with elementary analyses indicated that only the amino group was acylated. The ester derivatives of these compounds were prepared either by esterification of the N-dichloroacetyl-DL-amino acid with diazomethane or by the reaction of the amino acid ester with dichloroacetyl chloride in the presence of triethylamine. The sodium salts and the esters were tested for antitumor activity against sarcoma 37 in mice and Walker carcinoma 256 in rats. In both cases regression of the tumors was obtained.



1960 ◽  
Vol 1 (2) ◽  
pp. 173-188 ◽  
Author(s):  
O. G. Fahmy ◽  
Myrtle J. Fahmy

The analysis of the variation in the mutation rate in the fractionated progeny of treated males, revealed a marked differential cell stage response to the various chemical series investigated. The mustard derivatives of amino-acids (particularly L-phenylalanine) exert their minimal mutagenicity on mature sperm, but possess an appreciable activity on other stages of spermatogenesis, including spermatogonia. The carboxylic-acid mustards produce their maximal effect on an early spermatid, but are practically ineffective on spermatocytes and spermatogonia. The amine mustard corresponding to the phenylalanine derivative is effective on the stages of spermiogenesis (including the early spermatids) as well as on the spermatocytes, but is inactive on the spermatogonia (at least the primary stages). The response of the gonia, therefore, is a function of the amino-acid moeity of the mutagen, and is not merely due to the presence of an amino-group in the molecule.



1970 ◽  
Vol 120 (4) ◽  
pp. 873-876 ◽  
Author(s):  
Franca Serafini-Cessi ◽  
C. Cessi

1-C-(1-Acetylacetonyl)-2-deoxy-2-(1-methyl-3-oxobut-1-enyl)amino -d-galactitol is obtained from the condensation of 2-amino-2-deoxy-d-galactose with pentane-2,4-dione in anhydrous solvent. On treatment with hot alkali it gives 2-methylpyrrole with 37% yield. By acid hydrolysis under mild conditions the compound loses the N substituent and from the resulting unstable derivative 2-methylpyrrole is obtained (52% yield). It is concluded that derivatives of aminohexoses substituted at C-1 with a dioxopentyl chain are the precursors of 2-methylpyrrole in the Cessi & Serafini-Cessi (1963) modification of the Elson–Morgan reaction. As demonstrated previously, products of condensation of aminohexoses with pentane-2,4-dione at the amino group are not converted directly into 2-methylpyrrole, but this step provides protection of the amino group during condensation at C-1.



1974 ◽  
Vol 27 (11) ◽  
pp. 2319 ◽  
Author(s):  
AB Goel ◽  
VD Gupta

The reaction of dialkyldichlorosilanes with amide oximes leads to cyclic products whose monomeric form has an l-oxa-3,5-diaza-2-silacyclopent-4-ene structure. These compounds exist mostly in adimeric form, occasionally monomeric or trimeric. Their infrared spectra have been interpreted. The secondary amino group of the compounds has been trisilylated.



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