Structure, antioxidant and α-amylase inhibitory activities of longan pericarp proanthocyanidins
Structure, antioxidant and α-amylase inhibitory activities of longan pericarp proanthocyanidins
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龙眼果皮原花青素的结构、抗氧化及α-淀粉酶抑制活性
DOI：
10.1016/j.jff.2015.01.041
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发表时间：
2015-04-01
影响因子：
5.6
通讯作者：
Yang, Hongshun
中科院分区：
文献类型：
--
作者：
Fu, Caili;Yang, Xuena;Yang, Hongshun
对龙眼果皮原花青素进行了提取，并进行了结构和生物活性分析。通过H-1和C-13核磁共振谱，首次鉴定出LPPs含有优势儿茶素/表儿茶素单元，平均聚合度为3.3。与此结果一致的是，电子喷雾电离（ESI）质谱显示，主要的LPPs是具有丰富的a型和b型键的聚儿茶素（epi）。LPPs的基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱显示出与原花青素三聚体相对应的[M + Na]（+）峰。通过ET-IR、NMR、ESI和MALDI-TOF质谱（MS）证实了LPPs单体单元中没食子酰基的存在。此外，LPPs具有较强的抗氧化活性（氧自由基清除能力ORAC）为1.23 × 104 μ mol TE/g， α -淀粉酶抑制活性IC50为0.075 mg/mL。这些结果表明，LPPs是一种很有前途的抗氧化剂，可以作为潜在的功能性食品成分加以应用。(C) 2015 Elsevier Ltd.版权所有。
Longan pericarp proanthocyanidins (LPPs) were extracted and examined by structural and bioactive analyses. By H-1 and C-13 NMR spectra, LPPs were identified for the first time containing dominant catechin/epicatechin units with a mean degree of polymerisation of 3.3. Consistent with this result, electron spray ionisation (ESI) mass spectra revealed that the predominant LPPs were poly(epi)catechin with abundant A-type and B-type linkages. Matrix-assisted laser desorption ionisation time of flight (MALDI-TOF) mass spectra of LPPs showed dominant [M + Na](+) peaks that corresponded to procyanidin trimers-octamers. The presence of galloyl group in monomeric units of LPPs was confirmed by ET-IR, NMR, ESI and MALDI-TOF mass spectrometry (MS). Moreover, LPPs had a strong antioxidant activity of 1.23 x 104 mu mol TE/g as measured by oxygen radical scavenging capacity (ORAC), and alpha-amylase inhibitory activity with IC50 for uncompetitive alpha-amylase inhibition of 0.075 mg/mL. These results indicate LPPs are promising antioxidant which could be applied as potential functional food components. (C) 2015 Elsevier Ltd. All rights reserved.