Convenient general synthesis of amidines

Rapid Comm Mass Spectrometry

2008

Picolinamidination of amino groups in peptides was carried out using ethyl picolinimidate tetrafluoroborate synthesized from picolinamide and triethyloxonium tetrafluoroborate. The N-terminal amino group as well as the epsilon-amino group of lysine were derivatized. The matrix-assisted laser desorption/ionization (MALDI) signal of a peptide was enhanced 20-35-fold upon picolinamidination depending on the number of amino groups derivatized. The signal enhancement effect is much higher than that of acetamidination or guanidination previously reported. Improved protein identification by mass mapping of the derivatized peptides was demonstrated.

Section: Methodsmentioning

confidence: 99%

Matrix‐assisted laser desorption/ionization signal enhancement of peptides by picolinamidination of amino groups

Rapid Comm Mass Spectrometry

2008

“…Ethyl picolinimidate (EPI) tetrafluoroborate was synthesized as reported [33]. Forty mg picolinamide (0.33 mmol) was dissolved in 670 L of anhydrous methylene chloride and 330 L of 1 M solution of triethyloxonium tetrafluoroborate in methylene chloride (0.33 mmol) was added.…”

Section: Synthesis Of Ethyl Picolinimidate Tetrafluoroboratementioning

confidence: 99%

Picolinamidination of phosphopeptides for MALDI-TOF-TOF mass spectrometric sequencing with enhanced sensitivity

Cui

J. Am. Soc. Mass Spectrom.

2009

Two orders of magnitude matrix-assisted laser desorption/ionization (MALDI) signal enhancement of phosphopeptides has been achieved by picolinamidination of N-terminal amine group and -amine group of lysine residues. Due to the presence of picolinamidination tag at the N-terminal amine of peptides, MS/MS spectra with a strong b-ion series was obtained, which greatly facilitated sequencing and identification of the phosphorylation site. Phosphorylation site of a phosphopeptide could be identified from MALDI TOF/TOF spectrum obtained from a tryptic or a chymotryptic phosphopeptide, which was not even detected in the positive ion mode, without signal enhancement by picolinamidination, due to the negative charge of the phosphate group in the presence of other peptides. (J Am Soc Mass

“…A reação ocorre à temperatura ambiente, em aproximadamente 24 h. Estes intermediários, mais estáveis que o fluoroborato de trietiloxônio, reagem com uma solução de amônia ou metilamina 8-9% em etanol absoluto. A reação é concluída após 3 dias, à temperatura ambiente 58 (Esquema 23).…”

Section: A Partir De Amidas E Tioimidatosunclassified

Principais métodos de síntese de amidinas

Santos¹,

Bernardino²,

Souza³

2006

Quím. Nova

Recebido em 8/6/05; aceito em 6/1/06; publicado na web em 6/7/06 SYNTHETIC APPROACHES TO AMIDINES. The amidine functional group is found in a wide range of natural products and is biologically active against several pathogens. In addition, amidines have long been regarded as useful intermediates in the synthesis of heterocyclic compounds. Consequently, a great number of methods have been developed for the preparation of amidines. Pinner's method is the most commonly used. Conventional methods include: -the addition of metal amides or amines to nitriles, the addition of amines to imido esters and the condensation of amides with amines in the presence of halogenating reagents. In this report, the main methods for synthesis of amidines will be described.