0000000000292840
AUTHOR
Xiao-jiang Hao
A new dibenzofuran and other constituents from Ligularia caloxantha, a Chinese medicinal plant.
A new dibenzofuran named 1,2,4-trimethyl-7,8-dimethoxy-dibenzofuran (1), together with seven known compounds, euparin (2), 2,5-diacetyl-6-hydroxy-benzofuran (3), 2-acetyl-5,6-dimethoxy-benzofuran (4), gummosogenin (5), lupeol (6), stigmasterol (7) and (E)-2,5-dihydroxy-cinnamic acid (8), were isolated from the roots of Ligularia caloxantha, a Chinese medicinal plant. The structures of the compounds were elucidated by spectroscopic methods.
The endoperoxide ascaridol shows strong differential cytotoxicity in nucleotide excision repair-deficient cells
Targeting synthetic lethality in DNA repair pathways has become a promising anti-cancer strategy. However little is known about such interactions with regard to the nucleotide excision repair (NER) pathway. Therefore, cell lines with a defect in the NER genes ERCC6 or XPC and their normal counterparts were screened with 53 chemically defined phytochemicals isolated from plants used in traditional Chinese medicine for differential cytotoxic effects. The screening revealed 12 drugs that killed NER-deficient cells more efficiently than proficient cells. Five drugs were further analyzed for IC50 values, effects on cell cycle distribution, and induction of DNA damage. Ascaridol was the most effe…
A petrol ether extract of the roots of Onosma paniculatum induces cell death in a caspase dependent manner
Traditional Chinese medicine (TCM) has become very popular in Western countries during the last years. Zicao, a remedy of TCM, has been traditionally used to treat cancer, and, its main constituents, naphthoquinones, have been reported to possess antitumor activity (Chen et al., 2002; Papageorgiou et al., 1999). Here, we prepared extracts of different polarities of Onosma paniculatum Bur.Franch., a plant which is amongst others used as Zicao, but, much less investigated. The extracts were analyzed concerning their growth inhibitory and apoptosis-inducing activity in various tumor cells.Cell viability was measured by XTT viability and a growth inhibition assay. Effects on the cell cycle and …
Preparation of ferulic acid derivatives and evaluation of their xanthine oxidase inhibition activity.
Several ferulic acid ethyl esters (3a-h) were synthesized under the Knoevengel reaction condition and they were further reduced to afford the respective allylic alcohol derivatives (4a-g). Some of them were evaluated for the xanthine oxidase (XO) inhibitory activity. Among them, 3h exhibited a significant inhibitory activity with an IC50 value of 1.35 x 10(-5) M, while the IC50 value of allopurinol used as the positive control was 1.49 x 10(-5) M. The study suggested that the higher acidity of the phenolic OH group in the ferulic acid derivatives might result in improved XO inhibitory activity.
Four new eremophilendiolides from Ligularia atroviolacea
From Ligularia atroviolacea, four new eremophilendiolides, 8 beta-hydroxy-eremophil-3,7 (11)-dien-12,8 alpha(14,6 alpha)-diolide (1), 8 beta-methoxy-eremophil-3,7(11)-dien-12,8 alpha(14,6 alpha)-diolide (2), 8 alpha-hydroxy-eremophil-3,7(11)-dien-12,8 beta(14,6 alpha)-diolide (3) and eremophil-3,7(11),8-trien-12,8 (14,6 alpha)-diolide (4), as well as a known diolide (5) were isolated. Their structures were elucidated on the basis of 1D and 2D NMR as well as ESI-MS spectral data. (c) 2006 Yu Zhao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.