Obtention and application of isoflavone standards from soybeans / Obtenção e aplicação de padrões de isoflavonas de soja

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The use of analytical standards in chromatographic analyses is very important to get trustworthy analytical results for validation of methodologies and for routine analyses. However, the cost of the available reference standards is high, prejudicing the overall analytical process. In this work, a transposition from analytical to preparative scale was carried out to obtain analytical standards of isoflavones from soybeans. An analytical methodology using high performance liquid chromatography (HPLC) was developed for separation and identification of isoflavones in dry soy extract. The transposition of the analytical parameters to the preparative scale was done initially through direct transposition. The characterization and purity of the isoflavones was determined by HPLC with spectra from a DAD detector, complemented by mass (MS+/-) and nuclear magnetic resonance spectrometries. The resulting isoflavone purities, after preparative separation and lyophilization, were 93.1 % for daidzin, 99.8 % for daidzein, 89.5 % for genistein and 87.7 % for glycitin, allowing their use as standards in routine analyses. To demonstrate the applicability of the standards obtained, an approach for extraction, acid hydrolysis and determination of the total amounts of isoflavone aglicones in soybeans was developed and validated. The results indicated total isoflavone contents of 283.5 ± 10.7 mg/100 g for non-transgenic (BRS133) and 228.2 ± 13.8 mg/100 g for transgenic (BRS245RR) soybeans, demonstrating significant differences in the isoflavone content of these two different soybeans.

ASSUNTO(S)

validation of methods cromatografia soybeans isoflavonas validação de metodo chromatography isoflavones soja

ACESSO AO ARTIGO

Documentos Relacionados