Collaborative Innovation Center of Ecological Civilization, School of Chemical Engineering and Technology, Hainan University, Haikou 570228, China.
Mar Drugs. 2022 Sep 29;20(10):616. doi: 10.3390/md20100616.
A mangrove endophytic fungus DHS-48 was found to be particularly productive with regard to the accumulation of substantial new compounds in our previous study. In order to explore its potential to produce more unobserved secondary metabolites, epigenetic manipulation was used on this fungus to activate cryptic or silent genes by using the histone deacetylase (HDAC) inhibitor sodium butyrate and the DNA methyltransferase (DNMT) inhibitor 5-azacytidine (5-Aza). Based on colony growth, dry biomass, HPLC, and H NMR analyses, the fungal chemical diversity profile was significantly changed compared with the control. Two new compounds, named phaseolorin J () and phomoparagin D (), along with three known chromones (-) and six known cytochalasins (-), were isolated from the culture treated with sodium butyrate. Their structures, including their absolute configurations, were elucidated using a combination of detailed HRESIMS, NMR, and ECD and C NMR calculations. The immunosuppressive and cytotoxic activities of all isolated compounds were evaluated. Compounds and moderately inhibited the proliferation of ConA (concanavalin A)-induced T and LPS (lipopolysaccharide)-induced B murine spleen lymphocytes. Compound exhibited significant in vitro cytotoxicity against the tested human cancer cell lines Hela and HepG2, which was comparative to the positive control adriamycin and fluorouracil. Our finding demonstrated that epigenetic manipulation should be an efficient strategy for the induction of new metabolites from mangrove endophytic fungi.
在我们之前的研究中，一种红树林内生真菌 DHS-48 在大量新化合物的积累方面表现出特别高的生产力。为了探索其产生更多未观察到的次生代谢产物的潜力，我们对这种真菌进行了表观遗传操作，使用组蛋白去乙酰化酶 (HDAC) 抑制剂丁酸钠和 DNA 甲基转移酶 (DNMT) 抑制剂 5-氮杂胞苷 (5-Aza) 来激活隐藏或沉默的基因。基于菌落生长、干生物量、HPLC 和 1H NMR 分析，与对照相比，真菌的化学多样性谱发生了显著变化。从用丁酸钠处理的培养物中分离得到了两种新化合物，命名为 phaseolorin J () 和 phomoparagin D ()，以及三种已知的色酮 (-) 和六种已知的细胞松弛素 (-)。通过详细的 HRESIMS、NMR、ECD 和 13C NMR 计算，确定了它们的结构，包括它们的绝对构型。评价了所有分离化合物的免疫抑制和细胞毒性活性。化合物 和 适度抑制 ConA（刀豆球蛋白 A）诱导的 T 和 LPS（脂多糖）诱导的 B 鼠脾淋巴细胞的增殖。化合物 对测试的人癌细胞系 Hela 和 HepG2 表现出显著的体外细胞毒性，与阳性对照阿霉素和氟尿嘧啶相当。我们的发现表明，表观遗传操作应该是从红树林内生真菌中诱导新代谢产物的有效策略。
