排序方式: 共有42条查询结果,搜索用时 187 毫秒
41.
Synchrotron radiation circular dichroism (SRCD) spectroscopy is an emerging technique for sensitive determination of protein secondary structures and for monitoring of conformational changes. An important issue for its adoption as a useful technique is whether the high-intensity low-wavelength vacuum ultraviolet radiation in the SRCD chemically damages proteins. In this paper, using horse myoglobin as a test sample, it is shown that extensive irradiation in the SRCD does not produce any change in the chemical nature of the protein as detected by either SDS gel electrophoresis or mass spectrometry. In addition, no changes in the protein secondary structure are detectable from the SRCD spectra after extensive exposure to the SRCD beam. 相似文献
42.
Abderrahmen Abdelli Oumayma Bejaoui Hajer Bougatef Sarra Ouni Assaâd Sila Hedi M'rabet Xavier Moreau Mohamed Lotfi Efrit Damien Prim 《Journal of heterocyclic chemistry》2023,60(1):96-105
An efficient synthesis of new γ,δ-insaturated δ-lactam and glutarimide derivatives bearing a phosphonomethyl group from a common allylphosphonate precursor is described. Our approach is based on a two-step procedure involving the preparation of phosphonated-1,5-ketoester and −1,5-diester followed by an amidation–heterocyclization sequence. The first step proceeds via Michael's addition of ethyl acetoacetate and diethyl malonate on an allylphosphonate starting material. The second step consists of a base-promoted intramolecular amidation-cyclization sequence with primary amines, which accounts for the construction of δ-lactams and glutarimide skeletons. We performed the evaluation of angiotensin I-converting enzyme (ACE) inhibition using an in vitro enzyme assay on six new compounds. Five compounds showed potent ACE inhibitory activity, with IC50 values ranging from 0.02 to 0.27 mg/ml. Compared with Captopril, used as a reference drug, two new glutarimide derivatives exhibited higher efficiency ACE inhibition activity. 相似文献