6511-00-8Relevant academic research and scientific papers
MW-enhanced high-speed deprotection of Boc group using p-TsOH and concommitant formation of N-Me-amino acid benzyl ester p-TsOH salts
Suresh Babu, Vommina V.,Patil, Basanagoud S.,Vasanthakumar, Ganga-Ramu
, p. 1795 - 1802 (2007/10/03)
A high-speed, complete deprotection of Boc group from Boc amino acids and protected peptide esters employing p-TsOH in toluene under microwave irradiation is found to be complete in 30s. The deprotection can be carried out in methanol and acetonitrile also. Under the present conditions, C-peptide benzyl esters and O-benzyl ethers have been found to be stable. This has permitted us to carry out the synthesis of [Leu]enkephalin employing the Boc/Bzl-group strategy. Further more, it has been found that both Nα-Fmoc and N α-Z groups are completely stable. The present conditions can be extended for the concomitant removal of the Boc group and the formation of C-benzyl amino acid esters as well. This has been utilized for the synthesis of N-Me amino acid benzyl esters starting from Boc-N-Me amino acids in a single step. Copyright Taylor & Francis, Inc.
The partial molar volumes of some tetra- and pentapeptides in aqueous solution: A test of amino acid side-chain group additivity for unfolded proteins
Hackel,Hinz,Hedwig
, p. 4843 - 4849 (2007/10/03)
Ten new peptides with the amino acid sequences glycyl-X-Y-glycine and glycyl-X-Y-Z-glycine, where X, Y and Z are amino acids with neutral side-chains, have been synthesized and the partial molar volumes at infinite dilution, V2/(o), have been determined for all these peptides in aqueous solution at 298.15 K. For several of the peptides, V2/(o) data have also been obtained over the temperature range 283.15 to 363.15 K using a scanning densimetric method. The V2/(o) results obtained are compared with those calculated using the principle of group additivity and the group partial molar volumes we have derived in earlier work. We have shown that our group partial molar volumes can be used to reliably predict the partial molar volumes over a wide temperature range of polypeptides that have neutral amino acid side-chains.
