Bioactivity-Guided Separation of Potential D₂ Dopamine Receptor Antagonists from Aurantii Fructus based on Molecular Docking Combined with High-Speed Counter-Current Chromatography

• Published in: Molecules (Basel, Switzerland) Vol. 23; no. 12; p. 3135
• Main Authors: He, Yingjie, Zhu, Shihao, Wu, Changqiao, Lu, Ying, Tang, Qi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 29.11.2018; MDPI
• Subjects: Acetic acid; Aurantii fructus; Biological activity; Butanol; Chemical compounds; Chromatography; D2 dopamine receptor antagonists; Dopamine; Dopamine D2 receptors; Eluents; Ethanol; Ethyl acetate; Flavonoids; Gastrointestinal diseases; Hexanes; High speed; high-speed counter-current chromatography; Mass spectrometry; Mass spectroscopy; Metabolites; Molecular docking; Motility; Naringenin; Natural resources; Neohesperidin dihydrochalcone; NMR; Nuclear magnetic resonance; Purity; Separation; Simulation; Solvents; Tangeretin; naringenin; molecular docking; Aurantii fructus; high-speed counter-current chromatography; D2 dopamine receptor antagonists
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules23123135

The typical compounds of Aurantii fructus (AF) reported in previous research were screened for their high antagonistic ability on the D₂ dopamine receptor (D₂R) in silico, and then bioactivity-guided separation was undertaken on the potential D₂R antagonists from AF using high-speed counter-current chromatography (HSCCC). Three flavanones, two polymethoxyflavonoids, and three coumarins were effectively isolated from ethanol extracts of Aurantii fructus (AF) by the use of a two-step HSCCC method, and their chemical structures were identified by mass spectrometry, ¹H-NMR, and C-NMR and compared with published data. Firstly, crude extract of 70% ethanol eluent (150 mg) was isolated by HSCCC using an -hexane-ethyl acetate- -butanol-methanol-0.05% acetic acid (1:3:1.8:1:5, / / / / ) solvent system, and compounds (naringin, 28 mg), (neohesperidin, 13 mg), (meranzin, 5 mg) and (poncirin, 3 mg) were successfully isolated with 98.5%, 95.1%, 97.7%, and 92.4% purity, respectively. Then, the crude extract of 95% ethanol eluent (120 mg) was isolated by -hexane- -butanol-ethanol (methanol)-0.05% acetic acid (2:0.6:1:3, / / / ) solvent system and compounds (meranzin, 3 mg), (meranzin hydrate, 4 mg), (isomeranzin, 6 mg), (nobiletin, 10 mg), and (tangeretin, 7 mg) were successfully isolated with 95.8%, 98.5%, 95.1%, 92.4%, and 97.7% purity, respectively. Naringenin, a parent structure of naringin with the excellent binding score of -9.3 kcal/mol, was completely in conjunction with the active site of D₂R, indicating that it is critical for the treatment of gastrointestinal dysfunction. The results indicated that the bioactivity-guided method is practical for the effective separation of active compounds from natural resources.