PTP1B inhibitory and cytotoxic C-24 epimers of Δ28-24-hydroxy stigmastane-type steroids from the brown alga Dictyopteris undulata Holmes
PTP1B inhibitory and cytotoxic C-24 epimers of Δ28-24-hydroxy stigmastane-type steroids from the brown alga Dictyopteris undulata Holmes
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DOI：
10.1016/j.phytochem.2017.11.013
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发表时间：
2018-02-01
期刊：
影响因子：
3.8
通讯作者：
Mao, Shui-Chun
中科院分区：
文献类型：
--
作者：
Feng, Mei-Tang;Wang, Ting;Mao, Shui-Chun
从褐藻dictyopterisisb /C、FIG和I/J中分离出10个含有不寻常的δ(28)-24羟基侧链的甾体甾类化合物，包括3对C-24外显体，dictyopterisins B/C、FIG和I/J，以及先前报道的2个类似物(24S)-和(24R)- saringo甾醇。它们的结构在广泛的光谱分析的基础上得到了阐明，它们在侧链的立体中心C-24的绝对构型是通过与相关已知化合物的H-1 NMR数据的直接比较确定的。用改良的Mosher法测定了dictyopterisins A、B和H的甾体核绝对构型。dictyopterisins D、E和dictyopterisin I的混合物显示出良好的PTP1B抑制活性，IC50值分别为1.88和3.47 μ M，与阳性对照齐墩果酸（IC50值为2.78 μ M）相当。此外，dictyopterisins D和E与dictyopterisins F-J的混合物对人癌细胞HL-60 （IC50为1.02 ~ 2.70 μ M）和A-549 （IC50为135 ~ 2.85 μ M）具有显著的细胞毒性。(C) 2017 Elsevier Ltd.。版权所有。
Ten stigmastane-type steroids bearing unusual Delta(28)-24-hydroxy side chains, dictyopterisins A-J, including three pairs of C-24 epimers, dictyopterisins B/C, FIG, and I/J, were isolated from the brown alga Dictyopteris undulata Holmes, together with two previously reported analogues, (24S)- and (24R)-saringosterol. Their structures were elucidated on the basis of extensive spectroscopic analysis, with their absolute configurations at the stereogenic center C-24 of the side chain being assigned by a direct comparison of H-1 NMR data with those of related known compounds. The absolute configurations of the steroidal nuclei of dictyopterisins A, B, and H were determined using the modified Mosher's method. The mixture of dictyopterisins D and E and dictyopterisin I exhibited promising PTP1B inhibitory activities with IC50 values of 1.88 and 3.47 mu M, respectively, comparable to the positive control oleanolic acid (IC50, 2.78 mu M). In addition, the mixture of dictyopterisins D and E and dictyopterisins F-J displayed significant cytotoxicities against the human cancer cell lines HL-60 (IC50 from 1.02 to 2.70 mu M) and A-549 (IC50 from 135 to 2.85 mu M). (C) 2017 Elsevier Ltd. All rights reserved.