The title compounds were prepared by the enzymatic resolution of the corresponding N-acetylated DL-amino acids methyl esters, which were obtained from t-butyl chloride via an 8-step synthesis.
Chemical synthesis of peptides and proteins has evolved into an indispensable tool for chemical biology. Peptide ligation is a straightforward technique for joining two short peptide fragments together via a native pe...Chemical synthesis of peptides and proteins has evolved into an indispensable tool for chemical biology. Peptide ligation is a straightforward technique for joining two short peptide fragments together via a native peptide bond to afford a larger natural peptide or protein. However, the junction sites are limited to several specific amino acids because most peptide ligations involve participation of the side-chain functional groups of the junction-site amino acids. To overcome such intrinsic limitations, "general"peptide ligations which do not rely on the side-chain functional group have been developed. This review summarized the recent developments in peptide ligations that are independent of side-chain functional group of ligation-junction-site amino acid.展开更多
The effects of the amino, hydroxyl, imidazole and carboxyl groups of Ser His on DNA cleavage reaction were studied. It was found that the amino and hydroxyl groups were essential for the DNA cleavage activity of Ser H...The effects of the amino, hydroxyl, imidazole and carboxyl groups of Ser His on DNA cleavage reaction were studied. It was found that the amino and hydroxyl groups were essential for the DNA cleavage activity of Ser His, and that anyone of them blocked would result into the loss of cleavage activity. The carboxyl group was not the necessary group. The presence of the imidazole group would enhance the cleavage activity. However, the histidyl serine dipeptide, as the formula isomer of Ser His with the inverse peptide sequence, could not cleave DNA at all. Based on the above experimental results, a presumed cleavage mechanism of Ser His on DNA was proposed. [WT5HZ]展开更多
研究梅岭霉素发酵过程中添加其主要组分M B 1所拥有的侧链前体-3,3-二甲基丙烯酸,使M B 1效价及其在总组分中的比例得到大幅度提高,达到提高产量并控制组分的目的。本文还对侧链前体的添加方式、添加时间以及添加浓度进行了优化。结果显...研究梅岭霉素发酵过程中添加其主要组分M B 1所拥有的侧链前体-3,3-二甲基丙烯酸,使M B 1效价及其在总组分中的比例得到大幅度提高,达到提高产量并控制组分的目的。本文还对侧链前体的添加方式、添加时间以及添加浓度进行了优化。结果显示,0h时添加6mm ol/L的侧链前体其产量最高,M B 1效价比对照高出43%,其在总组分中的比例达到了52.7%。展开更多
以N-Boc苏氨醛为起始原料,经Wittig、Meisenheimer重排和催化氢化系列反应,不对称合成了天然产物三尖杉酯碱的侧链酸,中间体及目标产物结构经核磁共振(1 H NMR、13 C NMR)、红外光谱和质谱表征.结果表明,所用合成方法具有产率高、反应...以N-Boc苏氨醛为起始原料,经Wittig、Meisenheimer重排和催化氢化系列反应,不对称合成了天然产物三尖杉酯碱的侧链酸,中间体及目标产物结构经核磁共振(1 H NMR、13 C NMR)、红外光谱和质谱表征.结果表明,所用合成方法具有产率高、反应条件温和、操作简单等优点;目标化合物的总收率达30%.展开更多
基金This work was supported by the Natural Science Foundation of Jiangsu Province.
文摘The title compounds were prepared by the enzymatic resolution of the corresponding N-acetylated DL-amino acids methyl esters, which were obtained from t-butyl chloride via an 8-step synthesis.
基金supported by the National Natural Science Foundation of China (21462023), and the Natural Science Foundation of Jiangxi Province (20143ACB20007, 20153BCB23018)
文摘Chemical synthesis of peptides and proteins has evolved into an indispensable tool for chemical biology. Peptide ligation is a straightforward technique for joining two short peptide fragments together via a native peptide bond to afford a larger natural peptide or protein. However, the junction sites are limited to several specific amino acids because most peptide ligations involve participation of the side-chain functional groups of the junction-site amino acids. To overcome such intrinsic limitations, "general"peptide ligations which do not rely on the side-chain functional group have been developed. This review summarized the recent developments in peptide ligations that are independent of side-chain functional group of ligation-junction-site amino acid.
文摘The effects of the amino, hydroxyl, imidazole and carboxyl groups of Ser His on DNA cleavage reaction were studied. It was found that the amino and hydroxyl groups were essential for the DNA cleavage activity of Ser His, and that anyone of them blocked would result into the loss of cleavage activity. The carboxyl group was not the necessary group. The presence of the imidazole group would enhance the cleavage activity. However, the histidyl serine dipeptide, as the formula isomer of Ser His with the inverse peptide sequence, could not cleave DNA at all. Based on the above experimental results, a presumed cleavage mechanism of Ser His on DNA was proposed. [WT5HZ]
文摘研究梅岭霉素发酵过程中添加其主要组分M B 1所拥有的侧链前体-3,3-二甲基丙烯酸,使M B 1效价及其在总组分中的比例得到大幅度提高,达到提高产量并控制组分的目的。本文还对侧链前体的添加方式、添加时间以及添加浓度进行了优化。结果显示,0h时添加6mm ol/L的侧链前体其产量最高,M B 1效价比对照高出43%,其在总组分中的比例达到了52.7%。
文摘以N-Boc苏氨醛为起始原料,经Wittig、Meisenheimer重排和催化氢化系列反应,不对称合成了天然产物三尖杉酯碱的侧链酸,中间体及目标产物结构经核磁共振(1 H NMR、13 C NMR)、红外光谱和质谱表征.结果表明,所用合成方法具有产率高、反应条件温和、操作简单等优点;目标化合物的总收率达30%.