Seventeen compounds, including three new pairs of coumarinolignoid enantiomers, (7' S,8' S)-sapiumins A-C (1a-3a) and (7' R,8' R)-sapiumins A-C (1b-3b), six new taraxerane triterpenoids, sapiumic acids A-F (4-9), and five known taraxerane triterpenoids (10-14), were isolated from an ethanol extract prepared from the stems and leaves of Sapium discolor. The structures of 1-9 and their relative configurations were determined by spectroscopic data analysis, and the absolute configurations of the coumarinolignoids 1a/1b-3a/3b and triterpenoids 6-9 were assigned using experimental and calculated ECD data. Compounds 1a/1b-3a/3b are the first coumarinolignoids to be reported from the genus Sapium. Among all the isolates, compounds 1b, 2a/2b, 3a/3b, and 6-9 inhibited nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells, with IC values of 1.7-15.3 μM.
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http://dx.doi.org/10.1021/acs.jnatprod.8b00585 | DOI Listing |
Acta Crystallogr E Crystallogr Commun
August 2024
Department of Chemistry, University of Manchester, Manchester, United Kingdom.
The X-ray crystal structure data of 12-α-fluoro-3β-hy-droxy-olean-28,13β-olide methanol hemisolvate, 2CHFO·CHOH, (), and 12-α-fluoro-3β-hy-droxy-taraxer-28,14β-olide methanol hemisolvate, 2CHFO·CHOH, (), are described. The fluoro-lactonization of oleanolic acid using Selectfluor yielded a mixture of the six-membered δ-lactone () and the unusual seven-membered γ-lactone () following a 1,2-shift of methyl C-27 from C-14 to C-13.
View Article and Find Full Text PDFSteroids
August 2021
Martin-Luther-University Halle-Wittenberg, Organic Chemistry, Kurt-Mothes-Str. 2, D-06120 Halle (Saale), Germany. Electronic address:
Reaction of 3-O-acetyl-oleanolic acid (3) with formic acid/hydrogen peroxide at 100 °C for several hours provides an extraordinary but simple pathway to a taraxeran-28,14 β -olide type triterpenoid while the same reaction at 0 °C occurred without re-arrangement of the carbon skeleton, and an oleanane-28,13 β -olide was obtained instead. The products from these reactions were subjected to a cytotoxicity screening employing several human tumor cell lines showing the latter compound not cytotoxic while the former was cytotoxic especially for MCF-7 (breast adenocarcinoma), and FaDu (hypopharyngeal carcinoma) cells. The highest cytotoxicity, however, was observed for 3 β, 12α, 13 β -trihydroxy-oleanan-28-oic acid (6) holding with EC = 4.
View Article and Find Full Text PDFBioorg Chem
June 2021
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:
Thirty new pentacyclic triterpenoids, including five oleanane-type (1-5), twenty-three ursane-type (9-23, 26-33) and two taraxerane-type (24 and 25), along with fourteen known triterpenoids, were isolated from the stems and branches of Enkianthus chinensis. Their structures were elucidated by extensive spectroscopic analyses, X-ray crystallographic data and electronic circular dichroism (ECD) techniques. Sixteen compounds (1-5, 9-13, 20, 22, 32, 34-36) bearing a gem-hydroxymethyl group at C-4 represent rare examples of pentacyclic triterpenoids.
View Article and Find Full Text PDFPhytochemistry
June 2021
Key Laboratory of Plant Resources Conservation and Sustainable Utilization & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China; University of Chinese Academy of Sciences, Beijing, China; South China Branch of Innovation Academy for Drug Discovery and Development, Chinese Academy of Sciences, Guangzhou, 510650, China.
Casuarina equisetifolia L. (Casuarinaceae), an actinorhizal plant, exhibits mutualistic symbiosis with Frankia and promotes nitrogen fixation in root nodules. While the exchange of metabolites between host plant and microsymbiont is well understood in legume symbioses, the situation in the symbiosis between nitrogen-fixing Frankia and actinorhizal plants is less clear.
View Article and Find Full Text PDFPhytochemistry
April 2021
School of Pharmacy, Wenzhou Medical University, Wenzhou, 325035, People's Republic of China. Electronic address:
Phytochemical investigation of the resin of Liquidambar formosana Hanc led to the separation and identification of five undescribed pentacyclic triterpenoids, including two lupane type, one taraxerane type, and two oleanane type triterpenoids, in addition to ten known analogues. Structures and relative or absolute configurations were elucidated by intensive spectroscopic methods, and single-crystal X-ray diffraction analysis. All isolated compounds were evaluated for their anti-angiogenic effects in vitro against VEGF-induced endothelial cell proliferation and migration in HUVECs.
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