Flavonolignans occur typically in Silybum marianum (milk thistle) fruit extract, silymarin, which contains silybin, isosilybin, silychristin, silydianin, and their 2,3-dehydroderivatives, together with other minor flavonoids and a polymeric phenolic fraction. Biotransformation of individual silymarin components by human microbiota was studied ex vivo, using batch incubations inoculated by fecal slurry. Samples at selected time points were analyzed by ultrahigh-performance liquid chromatography equipped with mass spectrometry. The initial experiment using a concentration of 200 mg/L showed that flavonolignans are resistant to the metabolic action of intestinal microbiota. At the lower concentration of 10 mg/L, biotransformation of flavonolignans was much slower than that of taxifolin, which was completely degraded after 16 h. While silybin, isosilybin, and 2,3-dehydrosilybin underwent mostly demethylation, silychristin was predominantly reduced. Silydianin, 2,3-dehydrosilychristin and 2,3-dehydrosilydianin were reduced, as well, and decarbonylation and cysteine conjugation proceeded. No low-molecular-weight phenolic metabolites were detected for any of the compounds tested. Strong inter-individual differences in the biotransformation profile were observed among the four fecal-material donors. In conclusion, the flavonolignans, especially at higher (pharmacological) doses, are relatively resistant to biotransformation by gut microbiota, which, however, depends strongly on the individual structures of these isomeric compounds, but also on the stool donor.

中文翻译：

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人粪便微生物群对水飞蓟素黄酮的生物转化。

黄酮木聚糖通常出现在水飞蓟（牛奶蓟）果实提取物中水飞蓟素中，其中含有水飞蓟宾，异水飞蓟宾，水飞蓟素，水飞蓟素及其2,3-脱水衍生物，以及其他次要类黄酮和聚合物酚类成分。离体研究了人类微生物群对水飞蓟素各个成分的生物转化，使用粪便浆料接种的分批培养。通过配备质谱仪的超高效液相色谱分析选定时间点的样品。使用浓度为200 mg / L的初始实验表明，黄酮木聚糖对肠道菌群的代谢作用具有抗性。在10 mg / L的较低浓度下，黄酮木聚糖的生物转化要比滑石粉的生物转化要慢得多，而紫杉醇在16 h后完全降解。水飞蓟宾 异水飞蓟宾和2,3-脱氢水飞蓟宾大多进行了脱甲基，水飞蓟素主要被还原。另外，还减少了水飞蓟素，2，3-脱氢水飞蓟素和2，3-脱氢水飞蓟素，并进行了脱羰基和半胱氨酸结合。对于任何测试的化合物，均未检测到低分子量酚代谢物。在四个粪便材料供体之间观察到了生物转化方面的强烈个体差异。总之，黄酮木聚糖，特别是在较高剂量（药理学）下，对肠道菌群的生物转化具有相对的抵抗力，但是，强烈依赖于这些异构体化合物的个体结构，还取决于粪便供体。3-脱氢水鞘磷脂和2，3-脱氢水鞘磷脂也被还原，脱羰基和半胱氨酸结合得以进行。对于任何测试的化合物，均未检测到低分子量酚代谢物。在四个粪便材料供体之间观察到了生物转化方面的强烈个体差异。总之，黄酮木聚糖，特别是在较高剂量（药理学）下，对肠道菌群的生物转化具有相对的抵抗力，但是，强烈依赖于这些异构体化合物的个体结构，还取决于粪便供体。3-脱氢水鞘磷脂和2，3-脱氢水鞘磷脂也被还原，脱羰基和半胱氨酸结合得以进行。对于任何测试的化合物，均未检测到低分子量酚代谢物。在四个粪便材料供体之间观察到了生物转化方面的强烈个体差异。总之，黄酮木聚糖，特别是在较高剂量（药理学）下，对肠道菌群的生物转化具有相对的抵抗力，但是，强烈依赖于这些异构体化合物的个体结构，还取决于粪便供体。在四个粪便材料供体之间观察到了生物转化方面的强烈个体差异。总之，黄酮木聚糖，特别是在较高剂量（药理学）下，对肠道菌群的生物转化具有相对的抵抗力，但是，强烈依赖于这些异构体化合物的个体结构，还取决于粪便供体。在四个粪便材料供体之间观察到了生物转化方面的强烈个体差异。总之，黄酮木聚糖，特别是在较高剂量（药理学）下，对肠道菌群的生物转化具有相对的抵抗力，但是，强烈依赖于这些异构体化合物的个体结构，还取决于粪便供体。