Miyake Yoshiaki, Minato Kenichiro, Fukumoto Syuichi, Yamamoto Kanefumi, Oya-Ito Tomoko, Kawakishi Syunro, Osawa Toshihiko
Fundamental Technical Research Department of Pokka Corporation Ltd., Aichi, Japan.
Biosci Biotechnol Biochem. 2003 Jul;67(7):1443-50. doi: 10.1271/bbb.67.1443.
Potent antioxidative hydroxyflavanones were produced with Aspergillus saitoi from hesperidin or naringin, which are flavanone glycosides in citrus fruit with weak antioxidative activity. The hydroxyflavanone produced from hesperidin was identified as 8-hydroxyhesperetin (8-HHE), a novel substance, and those from naringin were identified as carthamidin (6-hydroxynaringenin) and isocarthamidin (8-hydroxynaringenin) by FAB-MS, 1H-NMR and 13C-NMR analyses. The antioxidative activity of these hydroxyflavanones was examined by using the free radical-scavenging system of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the methyl linoleate oxidation system. The hydroxyflavanones (8-HHE, carthamidin, and isocarthamidin) exhibited stronger activity than the flavanone glycosides (hesperidin or naringin) and their aglycones (hesperetin or naringenin). The activity of 8-HHE and isocarthamidin was comparable to that of alpha-tocopherol, and that of carthamidin was weaker than that of isocarthamidin. The hydroxyflavanones, which were hydroxylated on A ring of flavanone by Aspergillus saitoi, were obtained as potent antioxidants.
强效抗氧化羟基黄酮是由斋藤曲霉从橙皮苷或柚皮苷中产生的，橙皮苷和柚皮苷是柑橘类水果中的黄酮糖苷，抗氧化活性较弱。从橙皮苷产生的羟基黄酮被鉴定为一种新物质8-羟基橙皮素（8-HHE），通过快原子轰击质谱（FAB-MS）、氢核磁共振（1H-NMR）和碳核磁共振（13C-NMR）分析，从柚皮苷产生的羟基黄酮被鉴定为红花素（6-羟基柚皮素）和异红花素（8-羟基柚皮素）。通过使用1,1-二苯基-2-苦基肼基（DPPH）自由基清除系统和亚油酸甲酯氧化系统来检测这些羟基黄酮的抗氧化活性。羟基黄酮（8-HHE、红花素和异红花素）表现出比黄酮糖苷（橙皮苷或柚皮苷）及其苷元（橙皮素或柚皮素）更强的活性。8-HHE和异红花素的活性与α-生育酚相当，而红花素的活性比异红花素弱。由斋藤曲霉在黄酮A环上羟基化产生的羟基黄酮是作为强效抗氧化剂获得的。
