Síntese e controle de qualidade da ureia enriquecida em 13C para diagnóstico da Helicobacterpylori (HP)

The aim of the study was to synthesize the urea (13CO(NH2)2), with 99% 13C atoms, and to perform a quality analysis for the diagnosis (breath test) of Helicobacter pylori. Furthermore, the process was submitted to economic analysis. The reaction was performed in a stainless steel reactor, lined with polytetrafluoroethylene, under low pressure and temperature. The synthesis method was shown to be appropriate (2.35 g; 81.9% yield), evidenced by physico-chemical and microbiological results, according to Brazilian legislation. The production and diagnosis costs were competitive compared with national and international market values, rendering this a valuable tool in clinical medicine

15N-labed glycine synthesis

This work describes a method for 15N-isotope-labeled glycine synthesis, as well as details about a recovery line for nitrogen residues. To that effect, amination of alpha-haloacids was performed, using carboxylic chloroacetic acid and labeled aqueous ammonia (15NH3). Special care was taken to avoid possible 15NH3 losses, since its production cost is high. In that respect, although the purchase cost of the 13N-labeled compound (radioactive) is lower, the stable tracer produced constitutes an important tool for N cycling studies in living organisms, also minimizing labor and environmental hazards, as well as time limitation problems in field studies. The tests were carried out with three replications, and variable 15NH3(aq) volumes in the reaction were used (50, 100, and 150 mL), in order to calibrate the best operational condition; glycine masses obtained were 1.7, 2, and 3.2 g, respectively. With the development of a system for 15NH3 recovery, it was possible to recover 71, 83, and 87% of the ammonia initially used in the synthesis. With the required adaptations, the same system was used to recover methanol, and 75% of the methanol initially used in the amino acid purification process were recovered.Este trabalho descreve um método para a síntese de glicina marcada no isótopo 15N, bem como detalhes da linha de recuperação dos resíduos nitrogenados. Para isso, foirealizada uma aminação de alfa-haloácidos, empregando-se o ácido carboxílico cloroacético e amônia aquosa marcada (15NH3). Especial cuidado foi tomado para evitar possíveis perdas de 15NH3, uma vez que o custo de produção é elevado. A esse respeito, embora o custo de aquisição do composto marcado em 13N (radioativo) seja inferior, o traçador estável produzido se configura numa importante ferramenta em estudos de ciclagem de N em seres vivos, minimizando também os riscos ocupacionais e ambientais, bem como os problemas de limitação de tempo em estudos de campo. Os testes foram realizados em triplicata variando-se o volume de 15NH3(aq) utilizado na reação (50, 100 e 150 mL), com a finalidade de aferir a melhor condição de trabalho, sendo as massas de glicina obtidas de 1,7, 2 e 3,2 g, respectivamente. Com o desenvolvimento do sistema para recuperação de 15NH3, foi possível recuperar 71, 83 e 87% da amônia inicialmente utilizada na síntese. Com as adaptações necessárias, o mesmo sistema foi utilizado na recuperação de metanol 75% do metanol utilizado inicialmente no processo de purificação do aminoácido

Síntese e controle de qualidade da ureia enriquecida em 13C para diagnóstico da Helicobacterpylori (HP) Synthesis and quality control of 13C-enriched urea for Helicobacter pylori (HP) diagnosis

The aim of the study was to synthesize the urea (13CO(NH2)2), with 99% 13C atoms, and to perform a quality analysis for the diagnosis (breath test) of Helicobacter pylori. Furthermore, the process was submitted to economic analysis. The reaction was performed in a stainless steel reactor, lined with polytetrafluoroethylene, under low pressure and temperature. The synthesis method was shown to be appropriate (2.35 g; 81.9% yield), evidenced by physico-chemical and microbiological results, according to Brazilian legislation. The production and diagnosis costs were competitive compared with national and international market values, rendering this a valuable tool in clinical medicine