Biomedical subjects

E Fenude

Publications and source records attributed to E Fenude.

2 recordsLinked to original sources

PubMed1996

Three protected tetrapeptides.

The structures of three protected tetrapeptides, containing the Boc-Gly-Gly-Phe-X-OMe chain, tert-butoxycarbonyl-glycy-glycl-phenylalanine-leucine methyl ester dihydrate, Boc-Gly-Gly-L-Phe-D-Leu-OMe, C25H38N4O7.2H2O, tert-butoxycarbonyl-glycy-glycl-phenylalanine-methionine methyl ester dihydrate, Boc-Gly-Gly-L-Phe-D-Met-OMe, C24H36N4O7S.2H2O and tert-butoxycarbonyl-glycy-glycl-phenylalanine-norleucine methyl ester dihydrate, Boc-Gly-Gly-D-Phe-L-Nle-OMe, C25H38N4O7.2H2O, are described. The three molecules have the same conformation on the tetrapeptide chain and display the same packing, consisting of couples of molecules linked head-to-tail by two hydrogen (N--H...O) bonds; other hydrogen bonds, also involving two water molecules of crystallization, link these couples together and give rise to a planar structure.

Amino Acid Sequence↗

PubMed1989

Conformationally constrained D,L-alternating oligopeptides.

The possibility of selectively reducing the number of beta-helical structures theoretically possible for a D,L-alternating peptide by using a N-methyl group as conformational constraint is considered. Some 1H-nmr data regarding Boc(L-Nle-D-Nle)3-L-Nle-D-MeNle-L-Nle-D-Nle-L-Nle-OMe (I), its formyl analogue (II), and the pentadecapeptide Boc(D-Leu-L-Leu)5-D-MeLeu-(L-Leu-D-Leu)2-OMe (III) are presented. It is shown that these alternating stereocooligopeptides with a N-methyl group in the (n - 3) (I and II) or (n - 4) position (III) differ drastically in their behavior from the corresponding nonmethylated compounds. In chloroform, I and II form predominantly -- beta 7.2-helices and III forms almost exclusively -- beta 5.6 or -- beta 7.2-helices. The helices are in every case those having the maximum possible number of interchain H bonds.

Isomerism↗