将1-赖氨酸盐酸盐转化为乙基1-赖氨酸二盐酸盐。该盐与偏苯三酸酐反应,得到相应的二酸(1)。微波辅助缩聚产生了一系列新型的聚(酰胺酰亚胺)(PAI a–i)。这些聚合物的固有粘度范围为0.23–0.66 dl g -1 ,显示出从+8.02到+15.11的光学活性(由于在聚合步骤中手性二酸的α和ε氨基之间没有明显的区域选择性,因此可以预测二酸部分沿聚合物主链的随机取向,并且“立构规整度”的概念”(无法在此研究中解决),并且容易溶于极性非质子溶剂。它们在362°C以上开始分解(T 10%),并显示119–153°C的玻璃化转变温度。上述所有聚合物均通过UV,FT-IR和1 H NMR光谱,元素分析,热重分析,DSC,比浓对数粘度和比旋光度进行了全面表征。
Modified natriuretic compounds and conjugates thereof are disclosed in the present invention. In particular, conjugated forms of hBNP are provided that include at least one modifying moiety attached thereto. The modified natriuretic compound conjugates retain activity for stimulating cGMP production, binding to NPR-A receptor, decreasing arterial blood pressure and in some embodiments an improved half-life in circulation as compared to unmodified counterpart natriuretic compounds. Oral, parenteral, enteral, subcutaneous, pulmonary, and intravenous forms of the compounds and conjugates may be prepared as treatments and/or therapies for heart conditions particularly congestive heart failure. Modifying moieties comprising oligomeric structures having a variety of lengths and configurations are also disclosed. Analogs of the hBNP compound are also disclosed, having an amino acid sequence that is other than the native sequence.
studied. The preparative results, the thermal stability of the photochemical substrate, and the limiting quantum yield values obtained from photoreactions with several nucleophiles suggest the possible usefulness of 2-fluoro-4-nitrophenyl ethers as biochemicalphotoprobes.
Synthesis of Pyrimido[2,1-b][1,3,5]Thiadiazines Containing Polyfluoroalkyl- and Amino Acid Fragments
作者:O. G. Khudina、A. E. Ivanova、Ya. V. Burgart、V. I. Saloutin
DOI:10.1007/s10593-014-1544-x
日期:2014.9
structural fragment of amino acid or its ester were synthesized by a multicomponent cyclization of 6-polyfluoroalkyl-2-thiouracils with formaldehyde and amines. The use of diamino acids allowed the preparation of bis(pyrimido-[2,1-b][1,3,5]thiadiazin-6-ones), containing an aliphatic linker with a carboxy group. Two of the synthesized compounds exhibited weak antituberculosis activity in vitro.
Synthesis of new compounds derived from metronidazole and amino acids and their esters as antiparasitic agents
作者:Ahmed T. Al-Masri、Haythem A. Saadeh、Ibrahim M. Mosleh、Mohammad S. Mubarak
DOI:10.1007/s00044-011-9689-y
日期:2012.8
A number of newcompounds derived from metronidazole and aminoacids and their esters have been synthesized through a reaction between 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid and a number of aminoacid esters in the presence of N,N′carbonyldiimidazole (CDI). Hydrolysis of the esters derivatives with sodium hydroxide (4%) followed by acidification with hydrochloric acid (3 M) afforded the corresponding
N-Terminal amino acid side-chain cleavage of chemically modified peptides in the gas phase: A mass spectrometry technique for N-terminus identification
作者:A CHACON、D MASTERSON、H YIN、D LIEBLER、N PORTER
DOI:10.1016/j.bmc.2006.05.060
日期:2006.9.15
the b or y-ion series in a peptide MS/MS spectrum as well as identification of the b1 - and yn-1 -ions can facilitate de novo analyses. Therefore, it is valuable to identify either amino-acid terminus. In previous work, we have demonstrated that peptides modified at the epsilon-amino group of lysine as a t-butyl peroxycarbamate derivative undergo free radical promoted peptide backbone fragmentation under