Synthesis and structural characterization of homochiral homo-oligomers of parent cis- and trans-furanoid-β-amino acids.
The synthesis of homochiral homo-oligomers of cis- and trans-3-aminotetrahydrofuran-2-carboxylic acids (parent cis- and trans-furanoid-β-amino acids, referred to as "cis-/trans-FAA") has been carried out to understand their secondary structures and their dependence on the ring heteroatom. The oligomers of two diastereomers have been shown to have a distinct left-handed helicity. The cis-FAA homo-oligomers show a 14-helix structure, in contrast to the homo-oligomers of cis-ACPC, which adopt a sheet like structure. The trans-FAA homo-oligomers were found to adopt a 12-helix structure, the same trend found in trans-ACPC homo-oligomers. With the help of ab initio calculations, the structural features of cis-ACPC and cis-FAA hexamers were compared. We believe that the more compact packing of the cis-FAA hexapeptide should be due to a more favorable interaction between the ring and the backbone amide hydrogen.
Division of Organic Chemistry, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411-008, India.
Sunil K
SK
Pandey
Ganesh F
GF
Jogdand
João C A
JC
Oliveira
Ricardo A
RA
Mata
Pattuparambil R
PR
Rajamohanan
Chepuri V
CV
Ramana
D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D017433:Protein Structure, Secondary; D013237:Stereoisomerism
D000596:Amino Acids; D001386:Azides; D002264:Carboxylic Acids; D005663:Furans; D010455:Peptides