1.Click chemistry aided synthesis of 1,4-substituted 1,2,3-triazole based N-Fmoc protected epsilon-amino acids: isolation, characterization and synthesis of novel triazole based unnatural amino acids.
Sureshbabu VV1, Narendra N, Hemantha HP, Chennakrishnareddy G. Protein Pept Lett. 2010 Apr;17(4):499-506.
A new class of 1,4-substituted 1,2,3-triazole-based unnatural amino acids is demonstrated by employing click reaction between N-Fmoc amino alkyl azides and propiolic acid. The resulting unnatural amino acids were isolated and then subjected to Fmoc deprotection to isolate 1,2,3-triazole based amino acids as stable solids. These new class of molecules were also used for chain extension from both N- and C-terminals to synthesize dipeptidomimetics bearing 1,2,3-triazole moiety in the backbone.
2.Solid-phase synthesis of O-glycosylated Nalpha-Fmoc amino acids and analysis by high-resolution magic angle spinning NMR.
Yao NH1, He WY, Lam KS, Liu G. J Comb Chem. 2004 Mar-Apr;6(2):214-9.
Direct O-glycosylation of amino acids bound to TentaGel resin with a number of glycosyl trichloroacetimidate donors results in high yields. The glycosylation reaction can be easily monitored by analyzing the bead-bound amino acids with high-resolution magic angle spinning (HR-MAS) NMR. These studies pave a new way for the construction of "one-bead one-compound" O-glycopeptide libraries with standard amino acid building blocks and appropriate glycosyl trichloroacetimidate donors.
3.Isocyanates of N alpha-[(9-fluorenylmethyl)oxy]carbonyl amino acids: synthesis, isolation, characterization, and application to the efficient synthesis of urea peptidomimetics.
Patil BS1, Vasanthakumar GR, Suresh Babu VV. J Org Chem. 2003 Sep 19;68(19):7274-80.
The Curtius rearrangement of Fmoc-amino acid azides 1 was carried out in toluene by refluxing the solution for 30 min. The resulting isocyanates 2 have been isolated as crystalline solids and are fully characterized by IR, (1)H NMR, (13)C NMR, and mass spectra. They are found to be stable for several months when stored at 4 degrees C. The acyl azides of Asp, Glu, Ser, Tyr, and Lys with side-chain protection having tert-butyl, benzyl, and Boc groups were also converted to the corresponding isocyanates 2h-m. The rearrangement of Fmoc-amino acid azides in toluene to isocyanates 2 under microwave irradiation was also accomplished. The direct exposure of solid azides to microwaves for 60 s led to the completion of the rearrangement. The resulting isocyanates, after recrystallization, were found to be analytically pure. The scale-up of the rearrangement, under microwave irradiation as tested up to 0.75 mol, posed no problems and led to the isolation of the isocyanates in 91-96% yield.
4.Determination of proline in wine using flow injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection.
Costin JW1, Barnett NW, Lewis SW. Talanta. 2004 Nov 15;64(4):894-8. doi: 10.1016/j.talanta.2004.03.065.
Flow injection methodology is described for the determination of proline in red and white wines using tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection. Selective conditions were achieved for proline at pH 10, while other amino acids and wine components did not interfere. The precision of the method was less than 1.00% (R.S.D.) for five replicates of a standard (4 x 10(-6)M) and the detection limit was 1 x 10(-8)M. The level of proline in white and sparkling wines using the developed methodology was equivalent to those achieved using HPLC-FMOC amino acid analysis. SPE removal of phenolic material was required for red wines to minimize Ru(bipy)(3)(3+) consumption and its associated effect on accuracy.
![Fmoc-Gly-OH-[2-13C]](https://resource.bocsci.com/structure/175453-19-7.gif)
