New diketopiperazine derivatives from a deep-sea-derived Nocardiopsis alba SCSIO 03039
作者:Qingbo Zhang、Sumei Li、Yuchan Chen、Xinpeng Tian、Haibo Zhang、Guangtao Zhang、Yiguang Zhu、Si Zhang、Weimin Zhang、Changsheng Zhang
DOI:10.1038/ja.2012.88
日期:2013.1
The strain SCSIO 03039 was isolated from a sediment sample in the Indian Ocean and was characterized as a Nocardiopsis alba species on the basis of its 16S rRNA gene sequence. Seven diketopiperazines (DKPs), including two new DKPs nocazines D (2a) and E (2b), and five known DKPs (1, 3â6), were isolated from N. alba SCSIO 03039, along with two known compounds 2-methoxy-1,4-naphthoquinone (7) and 1-hydroxy-4-methoxy-2-naphthoic acid (8). Their structures were elucidated by mass and NMR spectroscopic analyses. The structure of methoxyneihumicin (1), previously proposed in a conference poster lacking publicly available experimental data, was validated for the first time by detailed NMR analyses and X-ray diffraction study. The two enantiomers nocazines D (2a) and E (2b) were isolated as a mixture. Compounds 3 and 4 were only known as synthetic compounds before. Methoxyneihumicin (1) exhibited in vitro cytotoxicities against MCF-7 and SF-268 with IC50 values of 4.6 and 12.7âμM, respectively, better than those of 6 (22.0 and 20.6âμM). The other compounds showed less pronounced cytotoxities against three tested human cancer cell lines and no compounds displayed antibacterial activities toward four indicator strains.
菌株SCSIO 03039是从印度洋的沉积样本中分离出的,并根据其16S rRNA基因序列被鉴定为Nocardiopsis alba物种。从N. alba SCSIO 03039中分离出了七种二酰肽(DKPs),其中包括两个新的DKPs——nocazines D (2a)和E (2b),以及五种已知的DKPs(1,3-6),还分离出了两个已知化合物:2-甲氧基-1,4-萘醌(7)和1-羟基-4-甲氧基-2-萘酸(8)。它们的结构通过质谱和核磁共振光谱分析进行了阐明。先前在一个会议海报中提出的甲氧基尼胡米新(methoxyneihumicin, 1)结构,因缺乏公开可用的实验数据而未被验证,此次通过详细的核磁共振分析和X射线衍射研究首次得到了验证。两个对映异构体nocazines D (2a)和E (2b)作为混合物被分离。化合物3和4在此之前仅作为合成化合物被知晓。甲氧基尼胡米新(1)对MCF-7和SF-268细胞的体外细胞毒性表现出IC50值分别为4.6和12.7μM,优于化合物6(22.0和20.6μM)。其他化合物对三种测试的人癌细胞系表现出较弱的细胞毒性,且没有化合物对四种指示菌株显示抗菌活性。