In this study, we investigated the effects of dicaffeoylquinic acid derivatives, including 1,4-di-O-caffeoylquinic acid (1,4-DCQA), 3,4-di-O-caffeoylquinic acid (3,4-DCQA), 3,5-di-O-caffeoylquinic acid (3,5-DCQA), 4,5-di-O-caffeoylquinic acid (4,5-DCQA), and 1,5-di-O-caffeoylquinic acid (1,5-DCQA) on glucose-stimulated insulin secretion (GSIS) activity and α-glucosidase activity were compared in rat INS-1 pancreatic β-cells. The α-glucosidase inhibitory activities of dicaffeoylquinic acid derivatives were as follows: 1,4-DCQA > 1,5-DCQA > 3,4-DCQA > 4,5-DCQA > 3,5-DCQA. In INS-1 cells, dicaffeoylquinic acid derivatives showed no cytotoxic effect at any concentration (2.5–10 μM). In addition, the GSIS activities of dicaffeoylquinic acid derivatives were as follows: 4,5-DCQA > 3,4-DCQA > 1,4-DCQA > 3,5-DCQA > 1,5-DCQA. Treatment of INS-1 cells with 4,5-DCQA resulted in a marked increase in protein expression of extracellular signal-regulated protein kinases (ERK), insulin receptor substrate-2 (P-IRS-2), Akt, phosphoinositide 3-kinase (P-PI3K), and pancreatic and duodenal homeobox-1 (PDX-1), which might be related to its GSIS activity in INS-1 cells. These findings indicate that the location of the dicaffeoyl functional group influences the anti-diabetic activity of quinic acid.

中文翻译：

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二咖啡酰奎尼酸衍生物的胰岛素分泌和α-葡萄糖苷酶抑制作用

在这项研究中，我们研究了二咖啡酰奎尼酸衍生物的影响，包括 1,4-二-O-咖啡酰奎尼酸 (1,4-DCQA)、3,4-二-O-咖啡酰奎尼酸 (3,4-DCQA)、 3,5-二-O-咖啡酰奎尼酸 (3,5-DCQA)、4,5-二-O-咖啡酰奎尼酸 (4,5-DCQA) 和 1,5-二-O-咖啡酰奎尼酸 (1,在大鼠 INS-1 胰腺 β 细胞中比较了 5-DCQA) 对葡萄糖刺激的胰岛素分泌 (GSIS) 活性和 α-葡萄糖苷酶活性的影响。二咖啡酰奎尼酸衍生物的α-葡萄糖苷酶抑制活性如下：1,4-DCQA > 1,5-DCQA > 3,4-DCQA > 4,5-DCQA > 3,5-DCQA。在 INS-1 细胞中，二咖啡酰奎尼酸衍生物在任何浓度 (2.5–10 μM) 下均未显示出细胞毒性作用。此外，二咖啡酰奎宁酸衍生物的GSIS活性如下：4,5-DCQA > 3,4-DCQA > 1,4-DCQA > 3,5-DCQA > 1,5-DCQA。用 4,5-DCQA 处理 INS-1 细胞导致细胞外信号调节蛋白激酶 (ERK)、胰岛素受体底物 2 (P-IRS-2)、Akt、磷酸肌醇 3-激酶的蛋白质表达显着增加(P-PI3K)，以及胰腺和十二指肠同源框-1 (PDX-1)，这可能与其在 INS-1 细胞中的 GSIS 活性有关。这些发现表明，二咖啡酰基官能团的位置影响奎尼酸的抗糖尿病活性。