Determination of the Complete Absolute Configuration of Petriellin A

2006 ◽  
Vol 59 (6) ◽  
pp. 407 ◽  
Author(s):  
Luigi Aurelio ◽  
Robert T. C. Brownlee ◽  
Jason Dang ◽  
Andrew B. Hughes ◽  
Gideon M. Polya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Natural Product ◽  
Absolute Configuration ◽  
Structural Determination ◽  
Amino Acid Residues ◽  
The Common ◽  
The Absolute ◽  
Derivatives Of

We report the full structural determination of the depsipeptide petriellin A. The absolute configuration of the amino acid residues, N-methyl isoleucine and N-methyl threonine, have been determined by a combination of HPLC and TLC comparison of synthetic Marfey’s derivatives and Marfey’s derivatives of the natural product hydrolysate. The configuration of the chiral centres in these two N-methylated residues was found to be the same as those of the common unmethylated l-amino acids.

Studies in Thiohydantoin Chemistry. II. C-Terminal Sequencing of Peptides

1996 ◽  
Vol 49 (5) ◽  
pp. 551 ◽  
Author(s):  
F Casagranda ◽  
BM Duggan ◽  
A Kirkpatrick ◽  
RL Laslett ◽  
JFK Wilshire
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Side Chains ◽  
Amino Acid Residues ◽  
The Common ◽  
Derivatives Of

An investigation has been carried out into the thiocyanate degradation (AcOH/Ac2O/HSCN) procedure as it relates to the C-terminal sequencing of peptides, particular emphasis being placed on the sequencing of amino acid residues containing sensitive or functional side chains. Attempted C-terminal sequencing of several serine- and threonine -containing peptides stopped at these particular residues, and did not proceed further. It is concluded that sequencing of most of the common amino acids is achievable but that significant problems will have to be overcome before routine sequencing of proline , serine, threonine, arginine , and, in particular, aspartic and glutamic acids can be claimed. The action of base on the thiohydantoin derivatives of N,S- diacetylcysteine and N,S- diacetyl-β-methylcysteine causes β-elimination of thioacetic S-acid to give the corresponding olefinic thiohydantoins.

scholarly journals Rapid Organocatalytic Chirality Analysis of Amines, Amino Acids, Alcohols, Amino Alcohols and Diols with Achiral Iso(thio)cyanate Probes

2021 ◽  
Author(s):  
Eryn Nelson ◽  
Jeffrey S. S. K. Formen ◽  
Christian Wolf
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Rapid Determination ◽  
Amino Alcohols ◽  
Enantioselective Synthesis ◽  
Widespread Occurrence ◽  
Chiral Compounds ◽  
New Methods ◽  
The Absolute

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...

scholarly journals Determination of the Absolute Configuration of the Pseudo‐Symmetric Natural Product Elatenyne by the Crystalline Sponge Method

2016 ◽  
Vol 55 (8) ◽  
pp. 2678-2682 ◽  
Author(s):  
Sylvia Urban ◽  
Robert Brkljača ◽  
Manabu Hoshino ◽  
Shoukou Lee ◽  
Makoto Fujita
Keyword(s):  
Natural Product ◽  
Absolute Configuration ◽  
The Absolute

scholarly journals Chiral Resolution and Absolute Configuration of 3α,6β-Dicinnamoyloxytropane and 3α,6β-Di(1-ethyl-1H-pyrrol-2-ylcarbonyloxy)tropane, Constituents of Erythroxylum Species

2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Marcelo A. Muñoz ◽  
Solange Arriagada ◽  
Pedro Joseph-Nathan
Keyword(s):  
Stationary Phase ◽  
Natural Product ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Normal Phase ◽  
Vibrational Circular Dichroism ◽  
Chiral Resolution ◽  
Case Characteristic ◽  
The Absolute

Chiral resolution of (±)-3α,6β-dicinnamoyloxytropane (1) and (±)-3α,6β-di(1-methyl-1 H-pyrrol-2-ylcarbonyloxy)tropane (2), prepared by esterification of (±)-3α,6β-tropanediol (3), was achieved using an amylose-derived HPLC stationary phase and normal phase conditions. The corresponding vibrational circular dichroism (VCD) spectra provided the absolute configuration of the enantiomers as (-)-(3 R,6 R)-1, (+)-(3S,6S)- 1, (-)-(3 R,6 R)-2 and (+)-(3S,6S)- 2. In each case, characteristic VCD bands for the absolute configuration determination of the 3α,6β-tropandiol esters were observed. While the absolute configuration of natural 1, previously isolated from Erythroxylum hypericifolium, could not be established due to the lack of literature optical rotation values, that of catuabine E, previously isolated from E. vacciniifolium, is now assigned as (-)-(3 R,6 R)-2 by comparison with the optical rotation values of the prepared samples and the reported rotation of the natural product.

scholarly journals Absolute Stereochemistry of the β-Hydroxy Acid Unit in Hantupeptins and Trungapeptins

2016 ◽  
Vol 11 (1) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Deepak Kumar Gupta ◽  
Gary Chi Ying Ding ◽  
Yong Chua Teo ◽  
Lik Tong Tan
Keyword(s):  
Amino Acid ◽  
Structural Feature ◽  
Absolute Configuration ◽  
Hydroxy Acid ◽  
Hplc Analysis ◽  
The Absolute ◽  
Absolute Stereochemistry ◽  
Common Structural Feature ◽  
Acid Unit

The β-hydroxy/amino acid unit is a common structural feature of many bioactive marine cyanobacterial depsipeptides. In this study, the absolute stereochemistry of the β-hydroxy acid moieties in hantupeptins and trungapeptins were determined through their synthesis and HPLC analysis of the Mosher ester derivatives. Synthesis of two3-hydroxy-2-methyloctanoic acid (Hmoa) stereoisomers, (2 S,3 R)-Hmoa and (2 S,3 S)-Hmoa, were achieved using diastereoselective asymmetric method and the retention times of all four Hmoa isomers were established indirectly by RPLC-MS analysis of their Mosher ester derivative standards. Based on the retention times of the standards, the absolute configuration of the Hmoa unit in hantupeptin C (3) and trungapeptin C (6) was assigned as (2 R,3 S)- and (2 S,3 R)-Hmoa, respectively. The use of the Mosher's reagents, coupled with HPLC analysis, provided a viable alternative to the absolute stereochemical determination of β-hydroxy acid units in depsipeptides.

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