Synthesis of a new conformationally constrained glycoamino acid building block

A novel intramolecular hydrogen bonding between a side-chain pyridine ring and an amide hydrogen of the peptide backbone in tripeptides containing the new amino acid, α,α-di(2-pyridyl)glycine

“…[7][8][9][10] This makes them attractive building blocks for the construction of supramolecular devices with peptides as the framework. Recently, novel ,-disubstituted glycines which have additional functions are of growing interest: 4-aminopiperidine-4-carboxylic acid (Api) with a piperidine ring, 11 2,2,6,6-tetramethylpiperidine-N-oxyl-4-amino-4-carboxylic acid (TOAC) with a piperidine-N-oxide ring, [12][13][14][15][16] 9-aminofluorene-9-carboxylic acid (Afc) with a fluorene ring, 6,[17][18][19] 9-amino-4,5-diazafluorene-9-carboxylic acid (Daf) with a 4,5-diazafluorene ring, [20][21][22][23][24] conformationally constrained glycosylated amino acids, [25][26][27] 6-amino-1,11-(20-crown-6)-6,7-dihydro-5H-dibenzo-[a,c]cycloheptene-6-carboxylic acid ([20-C-6]-Bip), 28 3-thymine-1-( t butoxycarbonyl)aminocyclopentane-1-carboxylic acid, 29 etc., were reported.…”

Rational design of a Tn antigen mimic

“…Notably, although the synthesis of several biologically active peptides containing Ca-methylated amino acids has been described, 28,29 only some of them have been incorporated into glycopeptides. 23,26,27,30 Moreover, to the best of our knowledge, while the biological activity of some unnatural glycopeptides has been reported, 19,21 this particular type of glycopeptides containing Ca-methylated amino acids has not been tested yet in biological assays.…”

Non‐natural Amino Acids as Modulating Agents of the Conformational Space of Model Glycopeptides

“…[12] Scheme 3 shows the synthesis of Ac-(S)-MeSer * -NHMe, Ac-(R,R)-MeThr Glycopeptide Ac-(S)-MeSer * -NHMe was synthesized from derivative 1, which has been previously glycosylated by our group [13] to give 2. Further deprotection of the carboxylic acid and subsequent reaction with methylamine led to 4.…”

“…Column chromatography was performed on silica gel 60 (230-400 mesh). 1 H and 13 C NMR spectra were recorded on Bruker ARX 300 and Bruker Avance 400 spectrometers.…”

“…Microanalyses were carried out on a CE Instruments EA-1110 analyzer and are in good agreement with the calculated values. Compound 2 was synthesized from 1 according to a procedure reported in reference [13] and compound 7 was synthesized according a procedure reported in reference [10j].…”