Tri‐ and Bicyclic Taxoids from the Taiwanese Yew Taxus sumatrana |
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| Authors: | Lon‐Je Luh Mohamed?H?Abd El‐Razek Chia‐Ching Liaw Chen‐Tung?Arthur Chen Yun‐Sheng Lin Yao‐Haur Kuo Ching‐Te Chien Ya‐Ching Shen |
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| Institution: | 1. Institute of Marine Geology and Chemistry, National Sun Yat‐sen University, Kaohsiung 80424, Taiwan, R.O.C;2. School of Pharmacy, College of Medicine, National Taiwan University, Taipei 100, Taiwan, R.O.C, (phone: 886‐2‐2312‐3456 ext. 62226;3. fax: 886‐02‐23919098);4. Department of Marine Biotechnology and Resources, National Sun Yat‐Sen University, Kaohsiung 804, Taiwan, R.O.C;5. National Research Institute of Chinese Medicine, Taipei, Taiwan, R.O.C;6. Division of Silviculture, Taiwan Forestry Research Institute, Taipei, Taiwan, R.O.C |
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| Abstract: | Five new taxoids, including a new 2(3→20)‐abeo‐taxane with a 6/10/6‐membered ring system and four 3,8‐seco‐taxanes having a 6/12‐membered ring system, were isolated from an acetone extract of the leaves and twigs of the Taiwanese yew (Taxus sumatrana, Taxaceae). The structures were established as 2α,7β,10α‐triacetoxy‐5α‐hydroxy‐2(3→20)‐abeo‐taxa‐4(20),11‐dien‐9,13‐dione ( 1 ), (3E,8E)‐2α,9,10β, 13α,20‐pentaacetoxy‐7β‐hydroxy‐3,8‐secotaxa‐3,8,11‐trien‐5‐one ( 2 ), (3E,8E)‐2α,9,10β,13α,20‐pentaacetoxy‐5α,7β‐dihydroxy‐3,8‐secotaxa‐3,8,11‐triene ( 3 ), (3E,8E)‐9,10β,13α‐triacetoxy‐2α,7β,20‐trihydroxy‐5α‐(2E)‐cinnamoyloxy]‐3,8‐secotaxa‐3,8,11‐triene ( 4 ), and (3E,8E)‐2α,5α,7β,9,10β,13α‐hexaacetoxy‐20‐hydroxy‐3,8‐secotaxa‐3,8,11‐triene ( 5 ), respectively, on the basis 1D‐ and 2D‐NMR spectral analyses. The in vitro cytotoxic activity of compounds 1 – 5 against four human tumor cell lines, including HeLa (cervical epitheloid), WiDr (colon), Daoy (medulloblastoma), and Hep2 (liver carcinoma) tumor cells was evaluated. Whereas compounds 1 – 3 were inactive, the novel taxanes 4 and 5 showed significant cytotoxicity. |
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| Keywords: | Taxus sumatrana Cytotoxic activity Taxoids |
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