17681-93-5Relevant academic research and scientific papers
Polycationic gramicidin S analogues with both high antibiotic activity and very low hemolytic activity
Tamaki, Makoto,Harada, Takuji,Fujinuma, Kenta,Takanashi, Kazumasa,Shindo, Mitsuno,Kimura, Masahiro,Uchida, Yoshiki
, p. 1134 - 1138,5 (2012)
The substitution of each constituent amino acid residue of gramicidin S (GS), cyclo(-Val1,1′-Orn2,2′-Leu 3,3′-D-Phe4,4′-Pro5,5′-) 2 with Lys residue indicated that each side chain structure
IBTM-containing gramicidin S analogues: Evidence for IBTM as a suitable type II' β-turn mimetic
Andreu, David,Ruiz, Sergi,Carre?o, Cristina,Alsina, Jordi,Albericio, Fernando,Jiménez, María Angeles,De La Figuera, Natalia,Herranz, Rosario,García-López, María Teresa,González-Mu?iz, Rosario
, p. 10579 - 10586 (2007/10/03)
The 2-amino-3-oxohexahydroindolizino[8,7-b]indole-5-carboxylate system (IBTM) has been proposed as a dipeptide surrogate of type II' β-turns. To evaluate which of the 11bR and 11bS diastereomers of IBTM best reproduces the conformational properties of type II' β-turns, gramicidin S (GS), a cyclic antibiotic peptide that contains two such units, has been chosen as a test compound and the effect of either diastereomer on both conformation and activity of the resulting peptide analogues has been determined. A conventional approach to the cyclic peptide structure based on solution cyclization of a partially protected precursor was only practicable for the (S)IBTM diastereomer. As an alternative, a solid phase mediated cyclization approach has been devised and applied successfully to both gramicidin S and its Lys2,2' analogue, then extended to the (R)-IBTM-containing analogues. NMR conformational analysis has clearly shown that only the (R) diastereomer of IBTM is a suitable mimic of the type II' β-turn conformation typical of GS. Differences in antibacterial activity between the (S)- and (R)-IBTM-containing GS analogues confirm the conformational results.
