Identification of nicotianamine as a potential inhibitor of angiotensin I-converting enzyme in aqueous extract of okara dry powder

• Published in: Journal of food and nutrition research Vol. 60; no. 2; p. 161
• Main Authors: Nishibori, Naoyoshi, Sagara, Takefumi, Morita, Kyoji
• Format: Journal Article
• Language: English
• Published: Bratislava Vyskumny Ustav Potravinarsky 01-01-2021
• Subjects: Angiotensin; Angiotensin I; Antihypertensives; Cation exchange; Cation exchanging; Chromatography; Conversion; Enzymes; Food plants; High performance liquid chromatography; Liquid chromatography; Mass spectrometry; Mass spectroscopy; Nicotianamine; Okara; Peptides; Peptidyl-dipeptidase A; Powder
• ISSN: 1336-8672; 1338-4260

A powder was prepared from an autoclaved okara extract to increase the concentration of potential angiotensin I-converting enzyme (ACE) inhibiting substances contained in the extract, thereby enhancing its inhibitory activity to characterize active substances more easily. On the other hand, nicotianamine, one of phytosiderophores, is now drawing attention for its ACE-inhibiting activity and anti-hypertensive effect among foods of plant origin, and therefore anticipated as an active component other than short-chain peptides contained in okara extract. Then, to investigate potential ACE-inhibiting substances contained in okara, the extract of the powder was fractionated using reverse-phase high performance liquid chromatography, and nicotianamine in the active fraction separated with strong cation exchange column was identified using liquid chromatography-mass spectrometry. As a result, nicotianamine was detected in the active fraction regarding ACE inhibition, but not in the inactive fractions, thus providing indirect evidence for suggesting nicotianamine as a potential ACE-inhibiting substance in okara extract powder.