SYNTHESIS OF LABELED CARBOHYDRATES

标记碳水化合物的合成

• 批准号: 6120851
• 负责人: LOUIS A SILKS
• 金额: $ 7.79万
• 依托单位: UNIVERSITY OF CALIF-LOS ALAMOS NAT LAB
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-15 至 2000-01-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6120851
• 关键词: animal tissue; biological products; biomedical resource; drug adverse effect; enzymes; human tissue

The SIR provided 77 Se (94% enriched)Ebselen; 55mg 94% (77 Se)-diselenide (C26H2ON2 J2 Se2); 50mg Ebselen [60940-34-3] exhibits glutathioneperoxidase (GPO)-like activity and has been proposed as an anti-inflammatory drug. Its acute p.o. toxicity in mice is low (>6000mg/kg). However, it has been reported that ebselen reacts rapidly with sulfhydryl compounds which cleave the Se-N bond. Based on these findings one would expect ebselen to react with SH-dependent enzymes, e.g., pyruvate dehydrogenase, and to be considerably toxic. This paradoxon might be resolved by examining the Se compounds when isolated cells are exposed to ebselen. We plan to investigate covalent interactions of ebselen (and its derivatives) with enzymes containing functional SH groups and ebselen redox cycling in isolated cells. The chemical nature of covalent Se interactions is deduced from chemical shifts of the corresponding 77Se NMR signals in vitro using a JEOL SX270 NMR spectrometer. Highly enriched 77Se-ebselen is required for appropriate S/N ratios. Calibration is performed with ebselen and its diselenide. Pre-tests will use various commercial preparations of SH-functional enzymes. Whole cell turnover of ebselen after incubation with rat hepatoma cells (HTC) is assessed by measuring the appearance / disappearance of specific signals at approx. 920ppm and 450ppm in chloroform extracts. In contrast to studies with purified enzymes, the fate of ebselen in cultured cells is likely to be affected by cellular glutathione (GSH) contents. Thus, formation of mixed selenosulfides (GSSeR) has to be considered when dealing with intermediates of ebselen turnover. These intermediates may provide an explanation for the observed low toxicity of ebselen in vivo. Dismutation of GSSeR yielding GSSG + RSeSeR provides an important role for the diselenide in future studies

SIR 提供了 77 Se（94% 富集）Ebselen； 55毫克 94%（77 Se）-二硒化物（C26H2ON2 J2 Se2）； 50毫克依布硒啉 [60940-34-3] 具有谷胱甘肽过氧化物酶 (GPO) 样活性，并已被 建议作为抗炎药。 其急性PO。毒性 小鼠低（>6000mg/kg）。 但据报道，依布硒啉 与裂解 Se-N 键的巯基化合物快速反应。 根据这些发现，人们预计依布硒啉会与 SH 依赖性酶，例如丙酮酸脱氢酶，并且 毒性相当大。 这个悖论可以通过检查来解决 当分离的细胞暴露于依布硒啉时，硒会化合物。 我们计划 研究依布硒啉（及其衍生物）的共价相互作用 使用含有功能性 SH 基团的酶和依布硒啉氧化还原循环 在分离的细胞中。 共价 Se 相互作用的化学性质是 由相应 77Se NMR 信号的化学位移推导出来 使用 JEOL SX270 NMR 波谱仪进行体外分析。 高度浓缩 需要 77Se-ebselen 才能获得适当的信噪比。 校准是 用依布硒啉及其二硒化物进行。 预测试将使用各种 SH功能酶的商业制剂。 全细胞周转 评估依布硒啉与大鼠肝癌细胞 (HTC) 孵育后的效果 通过测量特定信号的出现/消失 约。 氯仿提取物中含量为 920ppm 和 450ppm。 相比之下 使用纯化酶研究依布硒啉在培养细胞中的命运 可能受到细胞谷胱甘肽 (GSH) 含量的影响。 因此，必须考虑混合硒硫化物（GSSeR）的形成 在处理依布硒啉中间体时。 这些 中间体可以解释观察到的低毒性 依布硒啉在体内。 GSSeR 的歧化产生 GSSG + RSeSeR 为二硒化物在未来的研究中发挥重要作用