Pteridines, XCV

Pteridines ◽  
1989 ◽  
Vol 1 (4) ◽  
pp. 199-210 ◽  
Author(s):  
Ronan John Lockart ◽  
Wolfgang Pfleiderer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Elemental Analysis ◽  
Nmr Spectra ◽  
Acid Anhydride ◽  
Activated Esters ◽  
Amino Acid Conjugates ◽  
Catalytic Hydrogenolysis ◽  
Benzyl Esters

SummaryA series of new amino acid-tetrahydropterin-conjugates has been synthesized starting from N 2-isobutyryl-6,7- dimethyl-5,6,7,8-tetrahydropterin (7). The amino acids have been attached in form of their esters (10 - 16) via a succinyl spacer to the N-5 position (17 - 23) or directly via the carboxyl function applying CBZprotected activated esters (35, 39). Acylation of 7 with N-benzyloxycarbonylglutamic acid anhydride led to the y-glutamyl derivative 41. Selective deblocking experiments were achieved by catalytic hydrogenolysis to cleave the benzyl esters (24-28, 36, 42) and by DBU treatment to eliminate the p-nitrophenylethyl group (24, 25) respectively. Further reaction with ammonia hydrolysed the isobutyryl group to give the free tetrahydropterin-amino acid-conjugates 29 - 32, 37 and 43. Also a carbamoyl-type conjugate (45) was obtained from 7 and benzyl phenylalanine N-carbonylimidazolide (44). The newly synthesized compounds have been characterized by elemental analysis, UV and IH-NMR spectra.

scholarly journals Synthesis and Atiplatelet of 2-(ethyl amino acid esters), Amino pyridyl 1,3- oxzine

2006 ◽  
Vol 2 (2) ◽  
pp. 91-97
Author(s):  
Mohamad Alajelee
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Elemental Analysis ◽  
Inhibitory Activity ◽  
Amino Acid Esters ◽  
Improved Method ◽  
Acid Esters

2-(N-glycyl ,Alanyl , leucinyl , isoleacinyl , methionyl , phenyl alanyl,  vilinyl methyl ester) , 2-Amino and 4- Amino pyrideyl -1,3- Benzoxazine -4- one were synthesized from the reaction of the corresponding amino acids ester , Amino pyridines with methyl cyano salicylate using improved method. The resulted benzoxazine derivative were tested for their Antiplatelet inhibitory activity , their IR , NMR (1H , 13C) were also studied and checked by elemental analysis.

scholarly journals Preparation of two Cyclobutadiene-steroid derivatives Theoretical Analysis of its Interaction with the μ, d, and k Opiod-receptors

2018 ◽  
Vol 34 (6) ◽  
pp. 2689-2702 ◽  
Author(s):  
Figueroa-Valverde Lauro ◽  
Rosas-Nexticapa Marcela ◽  
Mateu-Armand Virginia ◽  
Diaz-Cedillo Francisco ◽  
Hau-Heredia Lenin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Theoretical Analysis ◽  
Opioid Receptors ◽  
Elemental Analysis ◽  
Nmr Spectra ◽  
Chemical Structure ◽  
Inhibition Constant ◽  
Novel Therapy ◽  
High Affinity ◽  
Docking Model

The objective of this investigation was to develop two cyclobutadiene-steroid derivatives (compounds 6 or 7) to evaluate its theoretical interaction on µ, d, and k opioid-receptors. The synthesis of 6 or 7 was carried out using a series of reactions which involves. 1) addition/cyclization: 2) imination, 3) etherification and 4) oxy-functionalization. Chemical structure of all compounds was confirmed using elemental analysis and NMR spectra. In addition, a theoretical analysis on the interaction of compounds 6 or 7 with µ, d, and k opioid-receptors was evaluated using a docking model. The results showed that 6 or 7 may interact with different type of amino acids residues on surface of the µ, d, and k opioid-receptors. Other data, indicated that inhibition constant (Ki) involved in the interaction of compounds 6 or 7 with k receptor was less compared with the Ki present in the interaction with µ, d, receptors. These data indicated that 1) compounds 6 or 7 show a high affinity by k-receptor; 2) the cyclobutadiene analogs are particularly interesting, because these drugs may constitute a novel therapy for pain.

Metal Complexes of Biologically Important Ligands, CLXIX [1]. Palladium(II) and Platinum(II) N,O-Chelate Complexes (R3P)(Cl)M(α-aminoacidate) with the Anions of Serine, Threonine, 3,4-Dehydroproline and 4-Hydroxyproline

2008 ◽  
Vol 63 (2) ◽  
pp. 124-128 ◽  
Author(s):  
Elfriede Schuhmann ◽  
Wolfgang Beck
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Metal Complexes ◽  
Nmr Spectra ◽  
Palladium Complexes ◽  
Chelate Complexes ◽  
Potassium Salts ◽  
Single Isomer ◽  
C Nmr

The N,O-chelates M(3,4-dehydro-D,L-prolinate)2 (M = Ni, Cu) have been obtained from Ni(OH)2 or Cu(OH)2 and the amino acid. The complexes (R3P)(Cl)M(α-aminoacidate) (M= Pd, Pt) have been synthesized from the chloro bridged compounds (R3P)(Cl)M(μ-Cl)2M(PR3)Cl (M = Pd, Pt; R = Et, n-Bu, Ph) and the potassium salts of the α-amino acids D,L-serine, D,L-threonine, 3,4-dehydro-D,Lproline and 4-hydroxy-L-proline. According to the 31P NMR and 13C NMR spectra the complexes with serinate and threoninate are formed as mixtures of cis/trans N-M-P isomers, whereas for the palladium complexes with 3,4-dehydroprolinate and 4-hydroxyprolinate a single isomer is observed

Comparative acidic cleavage experiments with methyl-substituted benzyl esters of amino acids

1967 ◽  
Vol 20 (10) ◽  
pp. 2243 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Amino Acid ◽  
Solid Phase ◽  
Hydrogen Bromide ◽  
Solid Phase Peptide Synthesis ◽  
Amino Acid Derivatives ◽  
Methyl Substitution ◽  
Benzyl Esters ◽  
Layer Chromatography

The action of trifluoroacetic acid and hydrogen bromide in acetic acid, respectively, on the benzyl, p-methylbenzyl, 2,4,6-trimethylbenzyl, and penta-methylbenzyl esters of some amino acid derivatives has been investigated by thin-layer chromatography. Methyl substitution greatly enhances the lability of the ester groups. The possible bearing of the results on solid-phase peptide synthesis is discussed.

Development of the Synthesis of Chromium and Molybdenum – Amino Acid Complexes: A Green Chemistry Approach

2015 ◽  
Vol 1101 ◽  
pp. 276-279
Author(s):  
Kun Sri Budiasih ◽  
Chairil Anwar ◽  
Sri Juari Santosa ◽  
Hilda Ismail
Keyword(s):  
Amino Acids ◽  
Magnetic Properties ◽  
Amino Acid ◽  
Complex Formation ◽  
Green Chemistry ◽  
Physical Properties ◽  
Elemental Analysis ◽  
Stable Condition ◽  
Molecular Formula ◽  
Optimum Ph

Some concepts of green chemistry were applied on the Synthesis of Chromium(III) and Mo(V) complexes with amino acids. Three concepts were used in this research were changing to safer solvent, using less energy and appliying a shorter process. The optimum pH of the complex formation of Chromium (III) is 4, whereas for Mo(V) complex, the most stable condition is at pH=1. The products were characterized by physical properties, Infrared and Uv-Vis spectrophotometer, Atomic Absorbtion Spectrophotometer, Elemental Analysis, and VSM (Vibrational Sample Magnetometer). The molecular formula of the complexes were predicted by simulation from the composition and the magnetic properties.

scholarly journals Synthesis of novel 1,10-phenanthroline-2,9-bis-α-amino acid conjugates

2000 ◽  
Vol 2000 (4) ◽  
pp. 170-171 ◽  
Author(s):  
Zhong-Ming Wang ◽  
Hua-Kuan Lin ◽  
Zhi-Fen Zhou ◽  
Shou-Rong Zhu ◽  
Tian-Fu Liu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Conjugates

Starting from 2,9-dimethyl-1,10-phenanthroline, the syntheses of eight novel 1,10-phenanthroline-2,9-bis-α-aminoacid conjugates (α-amino acids: DL-Ala, L-Val, L-Phe, L-His, L-Ile, L-Met, L-Glu, L-Asp) are described in detail.

scholarly journals Synthesis and Antimicrobial Activity of Amino Acids Conjugated Diphenylmethylpiperazine Derivatives

2009 ◽  
Vol 6 (s1) ◽  
pp. S473-S479 ◽  
Author(s):  
K. N. Shivakumara ◽  
K. C. Prakasha ◽  
D. Channe Gowda
Keyword(s):  
Amino Acids ◽  
Antimicrobial Activity ◽  
Amino Acid ◽  
Elemental Analysis ◽  
Coupling Agent ◽  
Antibacterial Activities ◽  
Antimicrobial Drugs ◽  
H Nmr

A series of amino acid conjugated diphenylmethylpiperazine derivatives were synthesized by coupling diphenylmethylpiperazine with different Boc-amino acids using EDCI/HOBt as coupling agent and NMM as base. The synthesized compounds were characterized by1H-NMR and elemental analysis. The Boc-deblocked derivatives were tested for their antimicrobial activity. We are here reporting that Phe and Trp conjugated diphenylmethylpiperazine showed equally good antibacterial activities as that of conventional antimicrobial drugs.

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