In vitro metabolism of anthocyanins by human gut microflora
In vitro metabolism of anthocyanins by human gut microflora
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DOI：
10.1007/s00394-004-0502-2
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发表时间：
2005-03-01
影响因子：
5
通讯作者：
Santos-Buelga, C
中科院分区：
文献类型：
--
作者：
Aura, AM;Martin-Lopez, P;Santos-Buelga, C
背景只有一小部分的膳食花青素被吸收。因此，大量摄入的化合物可能进入结肠。体外和体内研究表明，结肠细菌将各种黄酮类化合物转化为较小的酚酸。然而，很少有关于细菌转化花青素的信息。本研究的目的是探索花青素苷是否被去糖基化，所产生的糖苷配基是否被结肠细菌进一步降解为较小的酚类化合物，以及降解为代谢产物。方法以人粪便微生物为接种物，对分离的矢车菊素-3-葡萄糖苷和β-芸香糖苷进行体外发酵.通过HPLC-DAS和LC-MS分析和表征代谢物。通过将其特征与可用标准品的特征进行比较来鉴定代谢物，并使用初始时间点样品中分析的底物量进行半定量。结果矢车菊素-3-葡萄糖苷和矢车菊素苷元为矢车菊素-3-芸香糖苷的中间代谢产物。在早期的时间点（2小时前），原儿茶酸的形成作为一个主要的代谢产物的花青素糖苷和检测较低分子量的代谢产物表明，花青素被肠道微生物菌群转化。此外，糖苷配基与其他组的再缀合，对于膳食花青素苷来说是非典型的，在较晚的时间点（2小时后）是明显的。结论细菌对花青素的代谢包括糖苷键的断裂和花青素杂环的断裂。
Background Only a small part of the dietary anthocyanins are absorbed. Thus large amounts of the ingested compounds are likely to enter the colon. In vitro and in vivo studies have shown that colonic bacteria transform various flavonoids to smaller phenolic acids. However, there is very little information on bacterial transformations of anthocyanins. Aim of the study was to explore if anthocyanin glycosides were deglycosylated,whether the resulting aglycones were degraded further to smaller phenolic compounds by colonic bacteria, and to characterise metabolites. Methods Isolated cyanidin-3-glucoside and -rutinoside were fermented in vitro using human faecal microbiota as an inoculum. Metabolites were analysed and characterised by HPLC-DAS and LC-MS. They were identified by comparing their characteristics with those of available standards, and semi-quantified using the amount of substrate analysed from samples at initial timepoint. Results Cyanidin-3-glucoside and cyanidin aglycone could be identified as intermediary metabolites of cyanidin-3-rutinoside. At early timepoints (before 2 h), the formation of protocatechuic acid as a major metabolite for both cyanidin glycosides and detection of lower molecular weight metabolites show that anthocyanins were converted by gut microflora. Furthermore, reconjugation of the aglycone with other groups, non-typical for dietary anthocyanins, was evident at the later (after 2h) timepoints. Conclusions Bacterial metabolism of anthocyanins involves the cleavage of glycosidic linkages and breakdown of the anthocyanidin heterocycle.