ChemInform Abstract: In the Search for New Anticancer Drugs. Part 16. Selective Protection and Deprotection of Primary Amino Groups in Spermine, Spermidine and Other Polyamines.

1986 ◽  
Vol 17 (22) ◽  
Author(s):  
G. SOSNOVSKY ◽  
J. LUKSZO
1986 ◽  
Vol 41 (1) ◽  
pp. 122-129 ◽  
Author(s):  
George Sosnovsky ◽  
Jan Lukszo

Abstract Spermidine, spermine and other polyamines 1-5 were selectively protected at the terminal primary amino functions without affecting the secondary amino groups using N-ethoxycarbonyl-phthalimide (15), the Nefkens’ reagent. Three representative products, 17, 18 and 20, readily underwent acylation at the secondary amino nitrogen to give the corresponding compounds 21-26. Selective deprotection of two representative samples 22 and 25 at the primary amino function by hydrazinolysis yielded the corresponding derivatives 27 and 28 with free primary amino groups.In summary, the application of Nefkens’ reagent for the terminal protection of primary amino groups in various polyamines results in a simple, efficient and selective one-step procedure using commercially available reagents.


Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.


1992 ◽  
Vol 57 (10) ◽  
pp. 2187-2191 ◽  
Author(s):  
Jiří Jiráček ◽  
Tomislav Barth ◽  
Jiří Velek ◽  
Ivo Bláha ◽  
Jan Pospíšek ◽  
...  

Penicillin amidohydrolase (EC 3.5.1.11.) is one of the few enzymes used successfully for deprotection of primary amino groups of semisynthetic peptides. The available material is usually contamined by endo- and exopeptidases. We managed to prepare the enzyme devoid of trypsin- and chymotrypsin-like activities using affinity chromatography with specific ligands: Gly-D-Phe-Phe-Tyr-Thr-Pro-Lys-Thr (the fF peptide) and Leu-Gly-Val-D-Arg-Arg-Gly-Phe (the rR peptide). For further purification of the enzyme affinity chromatography with N-phenylacetyl-D-tert-Leu as a ligand was used.


2006 ◽  
Vol 3 (3) ◽  
pp. 149-151 ◽  
Author(s):  
S. Fiuza ◽  
A. Amado ◽  
Paulo Oliveira ◽  
Vilma Sardao ◽  
L. de Carvalho ◽  
...  

1983 ◽  
Vol 38 (7) ◽  
pp. 884-894 ◽  
Author(s):  
George Sosnovsky ◽  
Jan Lukszo

Abstract Several N-diethoxyphosphoryl derivatives 7 of various diaziridines, and compounds 12, 15a, 15b, 18 and 20, structurally related to TEPA (1a) and spin labeled Thio-TEPA (1c) were synthesized.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Suyeon Kim

Chitosan is obtained from alkaline deacetylation of chitin, and acetamide groups are transformed into primary amino groups during the deacetylation. The diverse biological activities of chitosan and its derivatives are extensively studied that allows to widening the application fields in various sectors especially in biomedical science. The biological properties of chitosan are strongly depending on the solubility in water and other solvents. Deacetylation degree (DDA) and molecular weight (MW) are the most decisive parameters on the bioactivities since the primary amino groups are the key functional groups of chitosan where permits to interact with other molecules. Higher DDA and lower MW of chitosan and chitosan derivatives demonstrated higher antimicrobial, antioxidant, and anticancer capacities. Therefore, the chitosan oligosaccharides (COS) with a low polymerization degree are receiving a great attention in medical and pharmaceutical applications as they have higher water solubility and lower viscosity than chitosan. In this review articles, the antimicrobial, antioxidant, anticancer, anti-inflammatory activities of chitosan and its derivatives are highlighted. The influences of physicochemical parameters of chitosan like DDA and MW on bioactivities are also described.


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