Reaction of Alantolactone, an Allergenic Sesquiterpene Lactone, with some Amino Acids. Resultant Loss of Immunologic Reactivity

1974 ◽  
Vol 52 (7) ◽  
pp. 575-581 ◽  
Author(s):  
G. Dupuis ◽  
J. C. Mitchell ◽  
G. H. N. Towers
Keyword(s):  
Amino Acids ◽  
Contact Dermatitis ◽  
Sesquiterpene Lactone ◽  
Sesquiterpene Lactones ◽  
Sulfhydryl Group ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Amino Group ◽  
Michael Type Addition ◽  
Methylene Group

A study of the reaction of a hapten, alantolactone, with some amino acids is reported. Previously, we have reported than an α-methylene group attached to the γ-lactone is the immunologic requisite of alantolactone and some other sesquiterpene lactones. Such a group is known to be capable of undergoing "Michael-type addition" with the sulfhydryl group of cysteine. We confirm this finding and report that alantolactone can also undergo addition with the imidazole group of histidine and with the ε-amino group of lysine, but not with the guanido group of arginine, the hydroxyl group of serine, or the thio ether function of methionine. We selected these amino acids for further study because of their nucleophilic side chain. Samples of alantolactone that have undergone such addition no longer produce allergic eczematous contact dermatitis, as measured by patch test.

scholarly journals ANTIGEN RECOGNITION AND THE IMMUNE RESPONSE

1972 ◽  
Vol 136 (2) ◽  
pp. 387-391 ◽  
Author(s):  
Sefik S. Alkan ◽  
Maurice E. Bush ◽  
Danute E. Nitecki ◽  
Joel W. Goodman
Keyword(s):  
Immune Response ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Low Molecular Weight ◽  
Carboxyl Group ◽  
Amino Group ◽  
Structural Requirements ◽  
Phenolic Ring ◽  
Cellular Immune ◽  
Charged Group

The low molecular weight compound L-tyrosine-azobenzenearsonate (RAT) induces a cellular immune response in guinea pigs. The contribution of the side chain of tyrosine to the immunogenicity of RAT and the structural requirements at that position for immunogenicity were assessed by synthesizing a series of analogs of RAT containing modifications in the side chain of tyrosine and employing them as immunogens. Removal of either the carboxyl or amino group did not markedly affect immunogenicity, measured by the induction of delayed cutaneous sensitivity, whereas deletion of both completely abolished it. However, a charged group was not required since side chains containing a polar hydroxyl group could substitute for chains bearing an amino or carboxyl group. The size of the side chain exerted a pronounced influence; the charged or polar substituent had to be extended from the phenolic ring by at least two carbon atoms in order to confer immunogenicity.

Specificity of the transport system for neutral amino acids in the hamster intestine

1962 ◽  
Vol 202 (5) ◽  
pp. 919-925 ◽  
Author(s):  
Edmund C. C. Lin ◽  
Hiroshi Hagihira ◽  
T. Hastings Wilson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Transport System ◽  
Side Chain ◽  
Carboxyl Group ◽  
Amino Group ◽  
Methyl Group ◽  
Neutral Amino Acids ◽  
Active Transport System ◽  
Everted Sacs

The specificity of the active transport system for neutral amino acids has been studied with everted sacs of hamster intestine. Amino acids with modifications or replacements of the carboxyl, amino, or α-hydrogen groups were poorly transported and were poor inhibitors of the transport of other l-amino acids. The carboxyl group must remain free, the amino group must not be in the tertiary or quaternary state, and the α-hydrogen can not be replaced by a methyl group without serious effect on the transport rate. It was concluded that the l-amino acids were distinguished from the d-isomers by the interaction of the carrier with the carboxyl group, the amino group, and the α-hydrogen. The side chain of the amino acid must be nonpolar but there is relatively little restriction on its structure.

Simple, Efficient, and Selective Synthesis of Phthaloylserine and Phthaloylthreonine

2015 ◽  
Vol 1088 ◽  
pp. 363-366
Author(s):  
Yu Ting Liu ◽  
Si Meng Song ◽  
Da Wei Yin ◽  
Dan Chen
Keyword(s):  
Amino Acids ◽  
Phthalic Anhydride ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Synthetic Method ◽  
Selective Synthesis ◽  
Protection Method ◽  
Amino Protection

An amino protection method was developed in which phthalic anhydride was used as the amino protection group, N,N-dimethylformamide (DMF) as solvent, L-threonine and L-serine with hydroxyl groups in side chain as the protected amino acids.The structures of products were confirmed by IR、1H NMR and 13C NMR. It is an efficient and simple protection method of amino acids with a hydroxyl group in the side chain.In addition, the synthetic method avoids the side reaction and significantly improves reaction yields(over 90%).

Succinimidyl esters of fatty acids for amino acid acylations

1976 ◽  
Vol 54 (5) ◽  
pp. 733-737 ◽  
Author(s):  
Alenka Paquet
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Side Chain ◽  
Amino Acid Esters ◽  
Amino Group ◽  
Acyl Chlorides ◽  
Hydroxysuccinimide Esters ◽  
Acid Esters

Fatty acid N-hydroxysuccinimide esters have been prepared from the thallium(I) salt of N-hydroxysuccinimide and the corresponding acyl chlorides in essentially quantitative yields. These active esters were used for acylation of amino acid esters in organic solvents, or of free amino acids in aqueous medium. The title compounds were found to be selective towards the side chain amino group of lysine. An efficient preparation of ε-N-benzyloxycarbonyl-L-lysine using benzyl succinimidyl carbonate is described.

One-step functionalization of carbon fiber using in situ generated aromatic diazonium salts to enhance adhesion with PPBES resins

RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70704-70714 ◽  
Author(s):  
Nan Li ◽  
Zuoqiang Wu ◽  
Lei Huo ◽  
Lishuai Zong ◽  
Yujie Guo ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Sulfhydryl Group ◽  
Hydroxyl Group ◽  
Diazonium Salts ◽  
Amino Group ◽  
Novel Approach ◽  
One Step

In the present study, we developed a novel approach to introduce amino group (–NH2), hydroxyl group (–OH) and sulfhydryl group (–SH) onto carbon fibers (CFs) using aromatic diazonium salts.

Recognition of β-lactam antibiotics by rat peptide transporters, PEPT1 and PEPT2, in LLC-PK1 cells

1997 ◽  
Vol 273 (5) ◽  
pp. F706-F711 ◽  
Author(s):  
Tomohiro Terada ◽  
Hideyuki Saito ◽  
Mayumi Mukai ◽  
Ken-Ichi Inui
Keyword(s):  
Phenyl Ring ◽  
Inhibition Constant ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Amino Group ◽  
Inhibitory Effects ◽  
Peptide Transporters

PEPT1 and PEPT2 are H+-coupled peptide transporters expressed preferentially in the intestine and kidney, respectively, which mediate uphill transport of oligopeptides and peptide-like drugs such as β-lactam antibiotics. In the present study, we have compared the recognition of β-lactam antibiotics by LLC-PK1 cells stably transfected with PEPT1 or PEPT2 cDNA. Cyclacillin (aminopenicillin) and ceftibuten (anionic cephalosporin without an α-amino group) showed potent inhibitory effects on the glycylsarcosine uptake in the PEPT1-expressing cells. Other β-lactams, such as cephalexin, cefadroxil, and cephradine (aminocephalosporins), inhibited modestly the PEPT1-mediated glycylsarcosine uptake. Except for ceftibuten, these β-lactams showed much more potent inhibitions on the glycylsarcosine uptake via PEPT2 than via PEPT1. Comparison of the inhibition constant ( K i) values between cefadroxil and cephalexin suggested that the hydroxyl group at the NH2-terminal phenyl ring increased affinity for both PEPT1 and PEPT2. It is concluded that PEPT2 has a much higher affinity for β-lactam antibiotics having an α-amino group than PEPT1 and that substituents at the NH2-terminal side chain of these drugs are involved in the recognition by both peptide transporters.

scholarly journals Synthesis of functionalised β-keto amides by aminoacylation/domino fragmentation of β-enamino amides

2018 ◽  
Vol 14 ◽  
pp. 2602-2606 ◽  
Author(s):  
Pavel Yanev ◽  
Plamen Angelov
Keyword(s):  
Amino Acids ◽  
Side Chain ◽  
Amino Group ◽  
Acylation Reactions

Ethylenediamine-derived β-enamino amides are used as equivalents of amide enolate synthons in C-acylation reactions with N-protected amino acids. Domino fragmentation of the obtained intermediates leads to functionalised β-keto amides, bearing a protected amino group in their side chain.

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