Ahmad Aliya, Ramasamy Kalavathy, Majeed Abu Bakar Abdul, Mani Vasudevan
Faculty of Pharmacy, Puncak Alam Campus, Universiti Teknologi MARA (UiTM) , Selangor Darul Ehsan , Malaysia and.
Pharm Biol. 2015 May;53(5):758-66. doi: 10.3109/13880209.2014.942791.
Soybean and its fermented products are the most common source of isoflavones in human food.
The present study quantifies the major glycosides and aglycones in soybean and its fermented product tempeh isoflavone extracts. The comparision of antioxidant effects and BACE1 inhibitory activity between the isoflavones of soybean and tempeh were also established.
The major isoflavones such as daidzein and genistein (aglycones), and their sugar conjugates (glycosides) daidzin and genistin in soybean and tempeh isoflavones were quantified using HPLC analysis. Comparative studies on BACE 1 (β-site amyloid precursor protein cleaving enzyme 1 or β-secretase 1) inhibition and free-radical scavenging activities (diphenyl-1-picrylhydrazyl (DPPH) and ferrous ion chelating ability) were conducted.
The amount of actives (mg/100 g) in soybean isoflavone compared with tempeh isoflavone is as follows: daidzein 16.72 mg/100 g versus 38.91 mg/100 g, genistein 11.10 mg/100 g versus 24.03 mg/100 g, daidzin 6.16 mg/100 g versus 0.69 mg/100 g, and genistin 24.61 mg/100 g versus 6.57 mg/100 g. The IC50 values of soybean and tempeh isoflavones against BACE1 were 10.87 and 5.47 mg/ml, respectively. The tempeh isoflavone had a more potent DPPH free-radical scavenging activity (IC50 = 2.67 mg/ml) than the soybean isoflavone (IC50 = 10 mg/ml). The ferrous ion chelating ability of the isoflavones was practically similar (IC50 = 10.40 mg/ml, soybean and 11.13 mg/ml, tempeh).
The present study indicates that tempeh is a healthy supplement to alleviate oxidative stress through the enrichment of aglycones.
大豆及其发酵产品是人类食物中异黄酮最常见的来源。
本研究对大豆及其发酵产品印尼豆豉异黄酮提取物中的主要糖苷和苷元进行定量分析。同时还对大豆和印尼豆豉异黄酮的抗氧化作用和β-分泌酶1（BACE1）抑制活性进行了比较。
采用高效液相色谱分析法对大豆和印尼豆豉异黄酮中的主要异黄酮，如大豆苷元、染料木黄酮（苷元）及其糖结合物（糖苷）大豆苷和染料木苷进行定量分析。对β-分泌酶1（β-位点淀粉样前体蛋白裂解酶1或β-分泌酶1）抑制活性和自由基清除活性（二苯基-1-苦基肼（DPPH）和亚铁离子螯合能力）进行了比较研究。
大豆异黄酮与印尼豆豉异黄酮中活性成分的含量（mg/100g）如下：大豆苷元16.72mg/100g对38.91mg/100g，染料木黄酮11.10mg/100g对24.03mg/100g，大豆苷6.16mg/100g对0.69mg/100g，染料木苷24.61mg/100g对6.57mg/100g。大豆和印尼豆豉异黄酮对BACE1的半数抑制浓度（IC50）分别为10.87mg/ml和5.47mg/ml。印尼豆豉异黄酮的DPPH自由基清除活性（IC50 = 2.67mg/ml）比大豆异黄酮（IC50 = 10mg/ml）更强。异黄酮的亚铁离子螯合能力实际相近（大豆异黄酮IC50 = 10.40mg/ml，印尼豆豉异黄酮IC50 = 11.13mg/ml）。
本研究表明，印尼豆豉是一种健康的补充剂，可通过富集苷元来减轻氧化应激。
