Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
J Agric Food Chem. 2024 Aug 28;72(34):18942-18956. doi: 10.1021/acs.jafc.4c02603. Epub 2024 Aug 15.
Not only free amino acids and normal short-chain peptides but also modified amino acids, such as -acetyl- and -formyl amino acids, monoamines, polyamines, and modified peptides, such as isomerized aspartyl peptides, pyroglutamyl peptides, and diketopiperazines, were identified in Japanese fermented soy paste () prepared using different fungal starters, rice, barley, and soybean- One hour after oral administration of water extract of soybean- to rats, the modified peptides increased significantly in the lumen upon the ingestion, while the normal peptides did not. In the blood from the portal vein and abdominal vena cava, 17 and 15 diketopiperazines, 16 and 12 isomerized aspartyl peptides, and 2 and 1 pyroglutamyl peptides significantly increased to approximately 10-400 nM, respectively. The modified peptides, which increased in rat blood, showed angiotensin-converting enzyme (ACE) inhibitory activity in a dose-dependent manner, indicating multiple ACE inhibitory peptides with high bioavailability in Among them, l-β-Asp-Pro showed the highest ACE inhibitory activity (IC 4.8 μM).
不仅游离氨基酸和正常短链肽，而且修饰氨基酸，如 -乙酰基- 和 -甲酰基氨基酸、单胺、多胺以及修饰肽，如异构化天冬氨酰肽、焦谷氨酸肽和二酮哌嗪，在使用不同真菌启动子、大米、大麦和大豆制备的日本发酵豆酱（）中被鉴定出来。在大鼠口服大豆水提取物后的 1 小时内，修饰肽在摄入时腔内显著增加，而正常肽则没有。在门静脉和腹静脉的血液中，17 和 15 个二酮哌嗪、16 和 12 个异构化天冬氨酰肽以及 2 和 1 个焦谷氨酸肽分别显著增加到约 10-400 nM。在大鼠血液中增加的修饰肽以剂量依赖性方式表现出血管紧张素转换酶（ACE）抑制活性，表明具有高生物利用度的多种 ACE 抑制肽。其中，l-β-Asp-Pro 表现出最高的 ACE 抑制活性（IC 4.8 μM）。
