Natural Products from Lindera reflexa

Characterization and identification of the chemical constituents in the root of Lindera reflexa Hemsl. using ultra-high performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry.[Pubmed: 27139818]

The root of Lindera reflexa Hemsl. (LR) is a newly discovered herbal drug and has been used to treat gastritis and peptic ulcers. Nevertheless, the chemical profile of LR has not been established. In this study, ultra-high performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MS) was performed to investigate the fragmentation behaviors of multiple compounds from LR. The 12 standards were divided into five types according to their basic skeletons: stilbenes, flavonoids, alkaloids, pyranone I and pyranone II. The MS(n) spectra of the [M+H](+) or [M±NH4](+) ions for these compounds provided a wealth of structural information on the five different types of compounds. Stilbenes yielded ions with successive loss of 78Da (C6H6) and 28Da (CO). The subsequent loss of H2O, CO, RDA and C-ring fragmentation were the most possible fragmentation pathways for flavonoids. Fragmentation with successive loss of 17Da (NH3) or 31Da (CH5N), 32Da (CH4O) and 28Da (CO) in the MS(n) spectra were characteristics of alkaloids. The characteristic ions for Pyranone I were m/z 255.1013, m/z 243.1013 and m/z 237.0909, and the diagnostic ions for Pyranone II were m/z 227.0700, m/z 215.0700, m/z 185.0594 and m/z 131.0489. Using accurate mass measurements for each precursor ion and the subsequent fragmented ions, a total of 42 compounds were identified or tentatively characterized in LR, including 24 potentially new compounds.

Secondary metabolites from the root of Lindera reflexa Hemsl.[Pubmed: 26176582]

Fourteen compounds were isolated from the root of Lindera reflexa Hemsl. Among these compounds, reflexan A (compound 1) was discovered to possess a novel skeleton and two stilbenes (compounds 2 and 3) were newly discovered compounds. Eleven known compounds (4-14) were also isolated, which included three alkaloids, one coumarin, four stilbenes, two flavonoids and katsumadain. The unusual structure of compounds 1, 2 and 3, along with their absolute configurations, was determined from UV, IR, HR ESI-MS, and 1D and 2D NMR data and by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. All of the isolates were tested with antitumor and anti-inflammatory assays. The results revealed that compounds 1, 2, and 3 all showed inhibitory activity toward three tumor cell lines, A549 (human lung carcinoma), BEL-7402 (human liver carcinoma) and HCT-8 (human colon carcinoma). None of the compounds exhibited anti-inflammatory activity.