title: Furostanol saponins from the seeds of Allium cepa L.
abstract: Allium cepa L. is one of the most widely cultivated and used plants. In addition to its bulb (onion), which is used as food in many cultures, the seeds of A. cepa L. are used as a traditional herbal medicine by the Uygur nationality in China to treat diarrhea and promote blood flow. In a bioactivity-screening, the ethanol extract of seeds of A. cepa L. showed inhibitory effects on protein tyrosine phosphatase 1B (PTP1B) enzyme, with 81.1% inhibition. Phytochemical investigation of the ethanol extract of red onion (Allium cepa L.) seeds led to the isolation of eight new furostanol saponins, named ceparosides E-L (1-8). Their structures were established using 1D and 2D NMR spectroscopy, mass spectrometry and chemical methods. Compounds 1-8 were screened for inhibitory effects on the PTP1B enzyme and cytotoxic activity against five human cells, including HCT-8, Bel-7402, BGC-823, A549 and A2780, but all were found to be inactive.
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China. Electronic address: lichuangjun@imm.ac.cn.
authors.forename: Chuang-Jun
authors.initials: CJ
authors.lastname: Li
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Teng-Fei
authors.initials: TF
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China. Electronic address: suyalun@imm.ac.cn.
authors.forename: Ya-Lun
authors.initials: YL
authors.lastname: Su
mesh_terms: D005956:Glucose-6-Phosphate Isomerase; D006801:Humans; D015394:Molecular Structure; D019697:Onions / Q000737:chemistry*; D010840:Phytosterols / Q000737:chemistry* / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry*
chemical_list: D010840:Phytosterols; D010936:Plant Extracts; D012503:Saponins; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D005956:Glucose-6-Phosphate Isomerase
keywords: Allium cepa L; Ceparosides E–L; Furostanol saponins; Liliaceae