Amino adds, derivatization

Rouse, J.G., Yang, J., Ryman-Rasmussen, J.P., Barron, A.R. and Monteiro-Riviere, N.A. (2007) Effects of mechanical flexion on the penetration of fullerene amino add-derivatized peptide nanopartides through skin. 

Disulfide connectivities of a partially reduced and alkylated peptide can be identified by the pairwise recognition of the specifically derivatized PTH-Cys on sequencing/46 PTH-Cys(Cam) and PTH-Cys(CM) are reported to elute on the ABI sequencer with PTH-Glu and PTH-Ser, respectively/46 and PTH-Cys(NEM) after PTH-Pro. 49 Therefore, it is important to know the primary structure of the target molecule in advance and to focus on the determination of its disulfide arrangement during sequence analysis in order to avoid mis-assignment of the amino adds at the cycles of the modified cysteine residues. 

Santerre and collaborators [72,73] also found that the plasma interaction of polyether urethanes was significantly altered by incorporation of sulfonate groups [73] which could be derivatized with amino adds [72]. The synergistic effect of pendant PEO and sulfonate groups grafted onto polyurethanes resulted in prolonged ex vivo occlusion times [482]. These results corresponded well with... 

To 4-alkoxybenzyl alcohol resin (100 mg, 0.45 mmol g, prewashed with CHjCb) in CH2CI2 (2mL) was added at 0 °C Emoc-Val-OH (4 equiv), B0C2O (4 equiv), Py (14 pL), and DMAP (2 mg). The mixture was gently stirred at 0°C under anhydrous conditions for 16 h. Then the resin was washed with DME (3x3 mL) and CHjCb (3x3 mL) and the substitution determined by cleavage of the Emoc group and absorbance measurement at 301 nm of the dibenzofulvene-piperidine adduct. Optical purity of the resin-bound amino acid was determined by the Marfey method. The 5deld of the derivatization of the 4-alkoxybenzyl alcohol resin was 86% and the content of D-amino add 0.3%. 

Resin-bound peptide mixtures (each approx. 5 mg, approx. 10 000 beads) containing one mixture position, introduced by coupling a mixture of 18 amino acids in a predetermined molar ratio (see Section 4.3.7.1.2), were hydrolyzed in 50% propionic add/HCl at 130 °C for 2h. Each hydrolysate was then submitted to amino add analysis using a derivatizer-analyzer system (Applied Biosystems) in conjunction with PTH derivatization. Two samples of each peptide-resin were hydrolyzed and analyzed in parallel. 

Fonnation of Isoindoks. In 1971 Roth described a sensitive analytical method for amino adds based on their reaction with o-phthaldia dehyde (OPA) and a thiol, 2-mercaptoethanol (117). The reaction produces an intensely fluorescent isoindole derivative of the amino acid and is specific for the primary amino group (118,119). Subsequently, the OPA method was extended to the enantiospedfic LC analysis of amino adds by substituting an optically active (single enantiomer) thiol for 2-mercaptoethanol in the derivatization reaction (120-122). This results in the formation of two... 

The solutes resolved by the Type IV CSPs must be able to form coordination complexes with transition metal ions. This limits the classes of compounds to a-amino acids and mono- and dicarboxylic acids containing an ot hydroxyl moiety. The most common solutes resolved on these CSPs are underivatized amino acids, although a number of derivatized amino acids can be resolved, including W-acetyl, amide, N-carbamoyl, N-carbo-benzoxy, and hydantoin derivatives, as well as complex amino adds such as the biochemical modulator BSD (79). 

Many chiral derivatization reactions were used and the compounds examined are mostly amphetamines, /3-blocking agents, amino adds, and anti-inflammatory drugs. Silica gel and, to a lesser extent, silanized silica were used as stationary phases. The Rf values obtained for the diastereomeric pairs were not usually very high (0.04 -0.07), with the exception of amino alcohol and amino acid diastereomers obtained with Marphey s reagent, a derivative of L-alanine amide (0.06 - 0.22). 

The nonderivatized amino adds, following their chromatographic separation, can either be directly detected as free amino acids, on-line derivatized, or by postcolumn derivatization. Derivatization with ninhy-drin, the classical amino add analysis, was the first re-... 

A novel route for the synthesis of piperazin-2-ones on a solid support relies on an intramolecular Mitsunobu reaction [111]. First, commercially available amino alcohols are attached to an aldehyde resin by reductive ami-nation. The alcohol function is protected and the secondary amine obtained is acylated with an amino add. Sulfonamide activation of the free amino group allows intramolecular alkylation through a Mitsunobu reaction, and thereby the formation of a derivatized ring. 

Lindroth, P. and K. Mopper. 1979. High performance liquid chromatographic determination of subpicomole amounts of amino adds by precolumn fluorescence derivatization with o-phthaldialdehyde. Anal. Chem. 51 1667-1674. 

USE Derivatizing agent for primary, secondary amines, la sequencing of peptides by Ed man degradation. In amino add analyses by HPLC (Pico-Tag). 

For urinary amino adds [22], 0.5 ml of urine was mixed with 0.5 ml of 0.5 M sodium bicarbonate and 2 ml of DABSCl (2 g P in acetone). The reaction mixture was maintained at pH 8.5-9.0 and 25-26 "C for 30 min. The filtrates were directly applied to a Cjg column for HPLC separation. Interfering amino compounds present in the urine also form derivatives with DABSQ, but may be removed by extraction with chloroform. Ammonia reacts readily with DABSCl, resulting in a derivative coeluted with DABS-methionine. Furthermore, ammonia may consume so much DABSCl that it seriously interferes with the derivatization of amino acids. Therefore the ammonia should be removed by lyophilizing the samples at pH 8.9 before derivatization. This method allowed the detection of urinary amino acid down to concentrations of about 16mgl ... 

Amines Amino Adds Amides and Imides Derivatization for GC Analysis... 

Fluorescence in combination with post-column derivatization Excitation and emission Ammonium, amino adds, and primary amines after reaction with OPA... 

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