分类: 医学、药学 >> 基础医学 提交时间: 2018-01-25 合作期刊: 《南方医科大学学报》
摘要: Objective To modify the structure of psoralidin using in vitro enzymatic glycosylation to improve its water solubilityand stability. Methods A new psoralidin glucoside (1) was obtained by enzymatic glycosylation using a UDP-glycosyltransferase. The chemical structure of compound 1 was elucidated by HR-ESI-MS and nuclear magnetic resonance(NMR) analysis. The high-performance liquid chromatography (HPLC) peaks were integrated and sample solution concentrations were calculated. MTT assay was used to detect the cytotoxicity of the compounds against 3 cancer cell lines in vitro. Results Based on the spectroscopic data, the new psoralidin glucoside was identified as psoralidin-6',7-di-O glucopyranoside (1), whose water solubility was 32.6-fold higher than that of the substrate. Analyses of pH and temperature stability demonstrated that compound 1 was more stable than psoralidin at pH 8.8 and at high temperatures. Only psoralidin exhibited a moderate cytotoxicity against 3 human cancer cell lines. Conclusion In vitro enzymatic glycosylation is a powerful approach for structural modification and improving water solubility and stability of compounds.
分类: 化学 >> 应用化学 提交时间: 2017-10-17
摘要: Phytochemical study on the aerial parts of Mikania micrantha led to the isolation of four new ent-kaurene diterpene glucosides, β-D-glucopyranosyl-15α-(3-hydroxy-3-methylbutanoyloxy)-9β-hydroxy-ent-16-kauren-19-oate (1), β-D-glucopyranosyl-15α-(3-methylbutanoyloxy)-9β-hydroxy-ent-16-kauren-19-oate (2), β-D-glucopyranosyl-15α-(2-methylbutanoyloxy)-9β-hydroxy-ent-16-kauren-19-oate (3), β-D-glucopyranosyl-15α-(3-methyl-2-butenoyloxy)-9β-hydroxy-ent-16-kauren-19-oate (4), along with a known one, β-D-glucopyranosyl-15α-(3-hydroxy-3-methylbutanoyloxy)-ent-16-kauren-19-oate (5). Their structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 1–4 are a group of C-9 hydroxylated ent-kaurene diterpene glucosides which is relatively rare in nature. These compounds selectively showed in vitro antibacterial activity against four assayed Gram-(+) and three Gram-(-) bacteria. In addition, the in vitro growth inhibitory activity of these compounds against human cancer cell lines Hela, A549, HepG-2 and MCF-7, were also tested.
分类: 生物学 >> 生物物理学 >> 免疫学 提交时间: 2016-05-12
摘要: NK cells play a pivotal role in innate immune responses against pathogenic infections. However, the underlying mechanisms driving defined NK functions remain largely elusive. In this study, we identified a novel endoplasmic reticulum (ER) membrane protein, ER adaptor protein (ERAdP), which is constitutively expressed in human and mouse NK cells. ERAdP is expressed at low levels in peripheral NK cells of hepatitis B virus-associated hepatocellular carcinoma patients. We show that ERAdP initiates NK cell activation through the NF-kappa B pathway. Notably, ERAdP interacts with ubiquitin-conjugating enzyme 13 (Ubc13) to potentiate its charging activity. Thus, ERAdP augments Ubc13-mediated NF-kappa B essential modulator ubiquitination to trigger the Ubc13-mediated NF-kappa B pathway, leading to NK cell activation. Finally, ERAdP transgenic mice display hyperactivated NK cells that are more resistant to pathogenic infections. Therefore, understanding the mechanism of ERAdP-mediated NK cell activation will provide strategies for treatment of infectious diseases.