Leojaponic acids A and B, two new homologous terpenoids, isolated from Leonurus japonicus / 中国天然药物

The present study aimed at isolation and purification of the bioactive terpenoids from the herb of Leonurus japonicus by chromatographic separations such as silica gel, sephadex LH-20 and C18 reversed phase silica gel, as well as preparative HPLC. As a result, leojaponic acids A (1, C17H24O4) and B (2, C18H26O4), two homologous terpenoids, together with (-)-loliolide (3), 1-(3-ethylphenyl) ethane-1, 2-diol (4) and dibutyl phthalate (5), were isolated from the EtOH extract of L. japonicus. All the chemical structures of the isolates were elucidated on the basis of 1D and 2D NMR analyses. Compounds 1 and 2 were new terpenoids, and Compounds 3 and 4 were isolated and identified for the first time from this plant. In addition, the α-glucosidase and tyrosinase inhibitory activity of the new compounds were evaluated.

miR-328 Inhibits K562 Cell Proliferation by Up-regulation of C/EBPα Expression / 中国实验血液学杂志

<p><b>OBJECTIVE</b>Our research was aim to investigate the effect of microRNA-328 (miR-328) on proliferation of chronic myeloid leukemia(CML) cell K562 and the mediated effect of C/EBPα.</p><p><b>METHODS</b>The eukaryotic expression vectors of miR-328 targeting gene and suppressor gene (hsa-miR-328 and hsa-miR-328-inhibitor) were constructed, and transfected into K562 cells respectively. The mRNA expression levels of miR-328 and C/EBP α were detected by real-time fluorescence quantitative RT-PCR; C/EBP α protein expression was detected by Western blot; CCK-8 was used to estimate the cell viability.</p><p><b>RESULTS</b>The recombinant genes of hsa-miR-328 and hsa-miR-328-inhibitor were successfully constructed and transfected into K562 cells. Fluorescent cells were observed after 24 h, and the visible fluorescence cells were gradually increased after 48 h or 72 h, the miR-328 showed no effect on the mRNA expression of C/EBPα detected by RT-PCR. Meanwhile, miR-328 showed recovering effect on C/EBPα translation and inhibition of K562 cells proliferation.</p><p><b>CONCLUSION</b>miR-328 has been successfully constructed and transfected into K562 cells, miR-328 inhibits the proliferation of K562 cells by up-regulation of C/EBPα.</p>