羊踯躅的代谢组学研究

目的:鉴定羊踯躅花、茎、叶的全部代谢物和不同部位间含量有差异的代谢物,分析差异代谢物的代谢通路。方法:采用广泛非靶向代谢组学对羊踯躅不同部位的代谢物进行比较分析。结果:共鉴定出535个代谢物,其中包括金合欢素、落新妇苷、苔黑酚龙胆二糖苷、去甲蟛蜞菊内酯、补骨脂定、秦皮素、络塞维等49个在其他植物中分离鉴定出的具有药用活性的化合物;鉴定出差异代谢物202个,包括β-氰基丙氨酸、蜀黍苷和黄曲霉毒素G23个有毒代谢物,且这3个有毒代谢物分别在花、茎、叶中含量最高;鉴定出百里香酚、丹皮酚、欧芹酚、东莨菪内酯、异泽兰黄素、野鸢尾黄素、石蒜碱和豆甾醇8个有药用价值的化合物,其在花、茎、叶中含量差异有统计学意义;排名前4位的差异代谢物通路中,花、茎、叶共有的通路为精氨酸生物合成,丙氨酸、天冬氨酸和谷氨酸代谢,以及氨酰基-tRNA生物合成通路,其中涉及花的通路还包括氰基氨基酸代谢通路。结论:羊踯躅中存在丰富的天然药用活性产物,使其药用价值并不限于毒性成分;氨基酸的合成与代谢是不同部位代谢物差异的主要原因。研究结果可为进一步筛选解析羊踯躅中药用价值较高的关键代谢物提供参考。

Metabolomics of Rhododendron molle (Blum) G. Don

Objective To identify the total and differential metabolites in the flowers, stems, and leaves of Rhododendron molle (Blum) G. Don and analyze the metabolic pathways involving the differential metabolites.Methods Widely untargeted metabolomics was employed to compare the metabolites among different tissues in R. molle.Results A total of 535 metabolites were identified. Among the metabolites, 49 bioactive compounds had been identified in other plant species, including acacetin, astilbin, orcinol gentiobioside, demethylwedelolactone, psoralidin, fraxetin, and rosavin. 202 differential metabolites were identified, including three poisonous compounds: 3-cyano-L-alanine, dhurrin, and aflatoxin G₂, which were most abundant in flowers, stems, and leaves, respectively. The content of eight medicinal compounds (thymol, paeonol, osthenol, scopoletin, eupatilin, irigenin, lycorine, and stigmasterol) differed between tissues. Flowers, stems, and leaves shared three of the top 4 metabolic pathways, namely arginine biosynthesis, alanine, aspartate, and glutamate metabolism, and aminoacyl-tRNA biosynthesis. Another pathway of the differential metabolites in flowers was cyanoamino acid metabolism.Conclusion The plentiful natural compounds including the toxic ones endow R. molle with a medicinal value. The metabolic pathway analysis demonstrates that the biosynthesis and metabolism of amino acids is the main reason for the metabolite differentiation among tissues in R. molle. The findings provide references for further screening and analyzing the key metabolites with higher medicinal values in R. molle.