Publications by authors named "Xiao-Meng Tian"
Sunflower pollen is a natural nutritious food with a long history and multiple functions, however, the main chemical components apart from flavonoids and their biosynthesis processes have not been thoroughly investigated. In this study, seven hydroxycinnamic acid amides (HCAAs) (1-7) abundant in sunflower pollen were isolated and identified as one type of the pollen's main chemicals. For a comprehensive understanding of HCAA biosynthesis in Helianthus annuus flowers, RNA-seq, metabolomics, and key genes related to biosynthesis in the sunflower were studied.
View Article and Find Full Text PDFCajuputones A-C, β-Triketone Flavanone Hybrids from the Branches and Leaves of Melaleuca cajuputi.
Chem Biodivers
November 2020
Three new β-triketone flavanone hybrids, cajuputones A-C were obtained from Melaleuca cajuputi (the Australian 'tea tree'). The structures of cajuputones A-C were elucidated by 1D/2D NMR spectroscopy and HR-ESI-MS analyses; and their absolute configurations were established by electric circular dichroism (ECD) calculations using TDDFT method. Structurally, cajuputones A-C feature a rare 6/6/6/6 oxatetracyclic ring system fused between an acylphloroglucinol-derived β-triketone and a pinocembrin or strobopinin moiety via an angle-type pyran-like motif.
View Article and Find Full Text PDFThe plants of genus Toona are well known for diverse limonoid secondary metabolites, while polyacetylenes are rarely found from Toona species. In this work, six new polyacetylenes toonasindiynes A-F (1-6) and six known analogues (7-12) were isolated from the root bark of Toona sinensis. Their structures and absolute configurations were elucidated by HRESIMS, 1D and 2D NMR spectroscopic analysis, modified Mosher's method, and biosynthetic consideration.
View Article and Find Full Text PDFArticle Synopsis
- - Eight new chemical compounds, including four limonoids, two steroids, one triterpenoid, and one lignan, were extracted from the stem barks of the Entandrophragma utile plant.
- - The structures of these compounds were identified using advanced spectroscopic techniques like HRESIMS and 1D/2D-NMR.
- - Bioactivity tests revealed that compounds 1, 6, and 7 can effectively reverse drug resistance in breast cancer cells, and compounds 5 and 6 showed moderate anti-inflammatory effects in activated macrophage cells.
Highly oxygenated and rearranged limonoids from the stem barks of Entandrophragma utile.
Phytochemistry
April 2020
Article Synopsis
- - Seventeen new and unique limonoids were extracted from the stem barks of the Entandrophragma utile tree in Ghana, including nine previously unreported types with specific structural configurations (entanutilins C-K) and three other novel limonoids (entanutilins L-N).
- - The chemical structures and configurations of these limonoids were determined using advanced analytical techniques like HRESIMS, NMR spectroscopy, CD exciton chirality, TDDFT/ECD calculations, and single-crystal X-ray diffraction.
- - Some of the isolated compounds showed promising bioactivity, effectively overcoming drug resistance in certain cancer cells (MCF-7/DOX) at a safe concentration of 30 µM, with an
Background: Immunocytes-involved inflammation is considered to modulate the damage in various diseases. Herein, novel therapeutics suppressing over-activation of immunocytes could prove an effective strategy to prevent inflammation-related diseases.
Purpose: The objective of this study is to evaluate the anti-inflammatory activity of Khayandirobilide A (KLA), a new andirobin-type limonoid with modified furan ring isolated from the Khaya senegalensis (Desr.