scholarly journals Solid-Phase Insertion of N-mercaptoalkylglycine Residues into Peptides

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4261
Author(s):  
Spyridon Mourtas ◽  
Dimitrios Gatos ◽  
Kleomenis Barlos
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Free Amino ◽  
Solid Phase ◽  
Amino Groups ◽  
Bromoacetic Acid ◽  
Nucleophilic Replacement

N-mercaptoalkylglycine residues were inserted into peptides by reacting N-free amino groups of peptides, which were initially synthesized on 2-chlorotrityl resin (Cltr) using the Fmoc/tBu method, with bromoacetic acid and subsequent nucleophilic replacement of the bromide by reacting with S-4-methoxytrityl- (Mmt)/S-trityl- (Trt) protected aminothiols. The synthesized thiols containing peptide–peptoid hybrids were cleaved from the resin, either protected by treatment with dichloromethane (DCM)/trifluoroethanol (TFE)/acetic acid (AcOH) (7:2:1), or deprotected (fully or partially) by treatment with trifluoroacetic acid (TFA) solution using triethylsilane (TES) as a scavenger.

Complex of Diphenylcyclopropenone with Substituted Acetic Acid and Formic Acid

1977 ◽  
Vol 32 (4) ◽  
pp. 453-454 ◽  
Author(s):  
Narendra S. Sridhara ◽  
Rajendra Singh
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Trifluoroacetic Acid ◽  
Bromoacetic Acid

Reaction of diphenylcyclopropenone with bromoacetic acid, trifluoroacetic acid and benzoylformic acid leads to crystalline complexes.

scholarly journals Process Control in the Solid Phase Peptide Synthesis by Titration of Free Amino Groups.

1969 ◽  
Vol 23 ◽  
pp. 2906-2907 ◽  
Author(s):  
K. Brunfeldt ◽  
P. Roepstorff ◽  
J. Thomsen ◽  
D. Heinegård ◽  
Alexandru T. Balaban ◽  
...  
Keyword(s):  
Process Control ◽  
Peptide Synthesis ◽  
Free Amino ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Amino Groups

Determination of Free Amino Acids in Banlangen Granule and its Fractions by Solid Phase Extraction Combined with Ion-pair High Performance Liquid Chromatography using a Corona-charged Aerosol Detector (SPE-HPLC-CAD)

2020 ◽  
Vol 16 ◽  
Author(s):  
Xiuyu Qian ◽  
Lixing Nie ◽  
Zhong Dai ◽  
Shuangcheng Ma
Keyword(s):  
Amino Acids ◽  
Trifluoroacetic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Performance ◽  
Solid Phase ◽  
Gradient Elution ◽  
Hplc Method ◽  
Ion Pair

Background: Banlangen granules are broad-spectrum effective antiviral drugs, and have a large clinical demand in China. Free amino acid is one of the main antiviral active ingredients of Banlangen granules. The preprocessing of samples by the existing pre-column derivatization reversed-HPLC method is complicated. Therefore, determination of free amino acids (AAs) by underivatized ion-pair HPLC-CAD is advantageous for simplifying preparation process and improving sensitivity. Objective: To better optimize AAs analysis methods, here, a sensitive SPE-HPLC-CAD method with a better resolution was established for the determination of underivatized AAs in Banlangen Granule for the first time. Method: The analytes were separated only by HPLC using a Hypercarb column with gradient elution of solvent A (20 mM nonafluorovaleric Acid in water) and solvent B (0.3% trifluoroacetic acid in acetonitrile-0.3% trifluoroacetic acid in water (1:9, v/v)) at a flow rate of 0.15 mL/min. N2 gas pressure and evaporation temperature of CAD were held at a constant 58.6 psi and 60 ℃, respectively. Results: This method was linear over the respective concentration range of six amino acids. The precision, accuracy, stability and recovery were satisfactory in all samples examined. And the method was successfully applied to determination of free amino acids in Banlangen granules and its fractions. The total contents of six amino acids in 28 batches of Banlangen Granule were between 1.36 mg/g-11.62 mg/g. Conclusion: The proposed method could be a simple, accurate and sensitive alternative approach for the determination of free AAs in Banlangen Granule.

COMPARATIVE STUDIES OF THE POTENTIATION OF CORTICOTROPHIN ACTIVITY BY SEVERAL INACTIVE DERIVATIVES

1963 ◽  
Vol 42 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Arthur I. Cohen ◽  
Edward H. Frieden
Keyword(s):  
Biological Activity ◽  
Comparative Studies ◽  
Free Amino ◽  
Hormonal Activity ◽  
Amino Groups

ABSTRACT A number of corticotrophin analogues have been prepared, some of which potentiate the biological activity of the untreated hormone in vitro. The free amino groups of corticotrophin appear to be essential not only for hormonal activity, but also for the interaction of the analogues with the tissue corticotrophin inactivating system which is assumed to account for the potentiating effect.

Coupling of Steroid O-(Carboxymethyl)oxime Derivatives with Single-Protected α,ω-Diaminoalkanes

1999 ◽  
Vol 64 (12) ◽  
pp. 2035-2043 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý ◽  
Pavel Drašar
Keyword(s):  
Trifluoroacetic Acid ◽  
Protecting Groups ◽  
Oxime Group ◽  
Amino Groups ◽  
New Approach ◽  
Terminal Amino ◽  
Oxime Derivatives

New approach to the synthesis of steroid oximes bearing O-substituents with terminal amino groups was described. The easily accessible steroid O-(carboxymethyl)oximes were reacted with single-protected Boc-α,ω-diaminoalkanes to give corresponding amide intermediates. From them the Boc protecting groups were cleaved with trifluoroacetic acid to afford the desired steroid derivatives with terminal amino groups. The procedure was succesfully tested on steroids with O-(carboxymethyl)oxime group in positions 7 and 17. The decomposition of target products was observed during deprotection of substituted 19-oximes.

scholarly journals FREE AMINO GROUPS OF EQUINE γ-GLOBULINS AND A SPECIFIC ANTIBODY

1955 ◽  
Vol 216 (2) ◽  
pp. 621-624
Author(s):  
Mary L. McFadden ◽  
Emil L. Smith
Keyword(s):  
Specific Antibody ◽  
Free Amino ◽  
Amino Groups ◽  
Γ Globulins

scholarly journals FREE AMINO GROUPS AND N-TERMINAL SEQUENCE OF RABBIT ANTIBODIES

1955 ◽  
Vol 214 (1) ◽  
pp. 185-196 ◽  
Author(s):  
Mary L. McFadden ◽  
Emil L. Smith
Keyword(s):  
Free Amino ◽  
Terminal Sequence ◽  
Amino Groups

Confirmatory Tests for Aflatoxin B1

1964 ◽  
Vol 47 (5) ◽  
pp. 801-803 ◽  
Author(s):  
Peter John Andrellos ◽  
George R Reid
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Formic Acid ◽  
Thionyl Chloride ◽  
Aflatoxin B1 ◽  
Trifluoroacetic Acid ◽  
Reaction Products ◽  
Confirmatory Tests ◽  
Aflatoxin B ◽  
Layer Chromatography

Abstract Three confirmatory tests have been devised to identify aflatoxin B±. Portions of the isolated toxin are treated with formic acid-thionyl chloride, acetic acid-thionyl chloride, and trifluoroacetic acid, respectively, and aliquots of the three fluorescent reaction products are spotted on thin-layer chromatography plates. Standards treated with each of the three reagents, plus an untreated standard, are spotted on the same plate, and after development the spots are compared under ultraviolet light.

PhFl acetic acid: A new linker for solid phase organic synthesis

1998 ◽  
Vol 39 (26) ◽  
pp. 4591-4594 ◽  
Author(s):  
Konrad H. Bleicher ◽  
James R. Wareing
Keyword(s):  
Acetic Acid ◽  
Organic Synthesis ◽  
Solid Phase ◽  
Solid Phase Organic Synthesis
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