Italian National Agency for New Technologies, Energy and Sustainable Development, Casaccia Research Centre, 00123 Rome, Italy.
Instituto Botánico, Departamento de Ciencia y Tecnología Agroforestal y Genética, Facultad de Farmacia, Universidad de Castilla-La Mancha, Campus Universitario, s/n, 02071 Albacete, Spain.
Molecules. 2017 Aug 20;22(8):1359. doi: 10.3390/molecules22081359.
This study set out to determine the distribution of sulfur compounds and saponin metabolites in different parts of garlic cloves. Three fractions from purple and white garlic ecotypes were obtained: the tunic (SS), internal (IS) and external (ES) parts of the clove. Liquid Chromatography coupled to High Resolution Mass spectrometry (LC-HRMS), together with bioinformatics including Principal Component Analysis (PCA), Hierarchical Clustering (HCL) and correlation network analyses were carried out. Results showed that the distribution of these metabolites in the different parts of garlic bulbs was different for the purple and the white ecotypes, with the main difference being a slightly higher number of sulfur compounds in purple garlic. The SS fraction in purple garlic had a higher content of sulfur metabolites, while the ES in white garlic was more enriched by these compounds. The correlation network indicated that diallyl disulfide was the most relevant metabolite with regards to sulfur compound metabolism in garlic. The total number of saponins was almost 40-fold higher in purple garlic than in the white variety, with ES having the highest content. Interestingly, five saponins including desgalactotigonin-rhamnose, proto-desgalactotigonin, proto-desgalactotigonin-rhamnose, voghieroside D1, sativoside B1-rhamnose and sativoside R1 were exclusive to the purple variety. Data obtained from saponin analyses revealed a very different network between white and purple garlic, thus suggesting a very robust and tight coregulation of saponin metabolism in garlic. Findings in this study point to the possibility of using tunics from purple garlic in the food and medical industries, since it contains many functional compounds which can be exploited as ingredients.
本研究旨在确定大蒜鳞茎不同部位中硫化合物和皂苷代谢物的分布。从紫蒜和白蒜生态型中获得了三个馏分：蒜衣（SS）、内（IS）和外（ES）部分。采用液相色谱与高分辨质谱（LC-HRMS）联用技术，结合主成分分析（PCA）、层次聚类（HCL）和相关网络分析等生物信息学方法进行分析。结果表明，这些代谢物在紫蒜和白蒜不同部位的分布不同，主要区别在于紫蒜中硫化合物略多。紫蒜的 SS 部分含有更多的硫代谢物，而白蒜的 ES 部分则富含这些化合物。相关网络分析表明，二烯丙基二硫醚是与大蒜中硫化合物代谢最相关的代谢物。紫蒜中的总皂苷含量几乎比白蒜高出 40 倍，ES 部分含量最高。有趣的是，五种皂苷，包括二烯丙基二硫化物-鼠李糖、原二烯丙基二硫化物、原二烯丙基二硫化物-鼠李糖、沃格尔苷 D1、satidoside B1-鼠李糖和 satidoside R1，仅存在于紫蒜中。皂苷分析得到的数据揭示了白蒜和紫蒜之间非常不同的网络，这表明大蒜中皂苷代谢存在非常强大和紧密的协同调控。本研究的结果表明，紫蒜的蒜衣可能用于食品和医疗行业，因为它含有许多功能化合物，可以作为成分加以利用。
