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111.
Two new phenethanol glycosides,named ligurobustoside P(1),ligurobustoside Q(2) have been isolated from the leaves of Ligustrum robustum,together with the known compound angoroside A(3) which was firstly isolated from this species.The structures of the two new phenethanol glycosides(1-2) were elucidated by a combination of high-resolution electron ionization mass spectrometry(HR-ESI-MS),1H NMR,13C NMR,HMQC,and HMBC spectra for the first time.  相似文献   
112.
制备了trans-[RuCl4(DMSO)(4-EtPy)]Na·2DMSO(4-EtPy=4-乙基吡啶)(化合物1)和trans-[RuCl4(DMSO)(4-EtPy)][(4-EtPy)H](化合物2).用UV、NMR研究了化合物在pH 7.40及5.00(0.15 mol·L-1 NaCl,37℃)缓冲液中的水解机理-动力学和溶液稳定性.测得各水解反应表观速率常数、半衰期.研究结果表明:两个化合物的Ⅰ氯、Ⅱ氯及DMSO水解反应机理均与NAMI-A相似,但其各级水解速率比NAMI-A略快,即用4-EtPy取代咪唑环,可加快NAMI-A衍生物的Ⅰ氯、Ⅱ氯及DMSO水解反应速率.在含氮配体相同时,NAMI-A衍生物比相应NAMI衍生物的稳定性稍好.化合物在酸性溶液中的稳定性高于中性溶液.提供了用核磁法定量测定NAMI-A衍生物的水解机理-动力学.  相似文献   
113.
The new secoiridoid sulfonates 1 – 3 were isolated from the 50% EtOH/H2O extract of the sulfiting‐processed Lonicera japonica Flos (LJF) by semi‐prep. HPLC, and their structures were identified on the basis of mass spectrometry and NMR spectroscopy. HPLC and LC‐DAD‐MS/MS analyses of the different samples of LJF obtained by various process techniques suggested that the sulfur fumigation led to the decrease of secologanic acid ( 4 ) and the formation of secologanic acid‐derived sulfonate 1 and its derivatives 2, 2a , and 3 in the crude materials, which revealed that sulfur fumigation, the traditional process technique, could alter the phytochemical profiles of some Chinese herbal medicines.  相似文献   
114.
李旭琴  刘安 《化学进展》2010,22(1):81-90
本文通过对ambiguine H、welwitindolinone A等几个复杂天然产物的无保护基法全合成与经典全合成进行分析对比,指出无保护基法合成可以减少合成步骤和原料的损失,是高效率的合成方法,即将成为天然产物全合成研究的热点。对于天然产物,为了避免过多使用保护基,可以采取“回到源头”模仿自然界的思路,尽量采取仿生合成法。但对非天然产物,解决问题的根本也要“回到源头”,致力于研究如何“控制化学选择性”,提高反应效率。在合成设计方面,尽可能增加C-C键反应在总反应步骤中的比例;合成中要先构建骨架,后安插需要的官能团;在构建骨架时,过渡金属催化反应或者自由基反应能够减少保护基的使用。最后,本文举例阐述了实现无保护基法合成的其他各种策略,指出为了减少保护基的使用,应该充分利用基团反应性差异,多研究新的合成方法。  相似文献   
115.
In this work, microwave-assisted ionic liquids treatment, followed by hydro-distillation (MILT-HD), as an efficient extraction technology, was used to extract essential oil. The purpose for this was to use multivariate analysis (MVA) models to investigate the effects of potential critical process parameters on the extraction efficiency of essential oil, and explore the mechanism of ionic liquids (ILs). According to the design of experiment (DoE), under optimal process conditions, the extraction efficiency of essential oil was dramatically enhanced, and had low energy demands. Since little is known regarding those mechanisms, according to the non-covalent interaction analysis, the underlying mechanism for ILs improving extraction efficiency was explored based on the density functional theory (DFT). The results showed that ILs could form intense non-covalent bond interaction with cellulose. It helped destroy the network hydrogen bond structure of cellulose in plant cells and caused the essential oils in the cells to be more easily exposed to the extraction solution, thereby accelerating extraction efficiency. Based on this work, it is conducive to understand the MILT-HD process better and gain knowledge of the mechanism of ILs.  相似文献   
116.
Traditional Chinese medicine (TCM) has been used for more than 2000 years in China. TCM has received wide attention recently due to its unique charm. At the same time, its main obstacles have attracted wide attention, including vagueness of drug composition and treatment mechanism. With the development of virtual screening technology, more and more Chinese medicine compounds have been studied to discover the potential active components and mechanisms of action. Molecular docking is a computer technology based on structural design. Network pharmacology establishes powerful and comprehensive databases to understand the relationship between TCM and disease network. In this review, emergent uses and applications of two techniques and further superiorities of the two techniques when embarked to boil down into a tidy system were illustrated. A combination of the two provides a theoretical basis and technical support for the construction of modern TCM based on the compatibility of components and accelerates the realization of two basic elements as well, including the clearness of the pharmacodynamic substances and explanation of the effect of TCM.  相似文献   
117.
Renal fibrosis progression is closely associated with aging, which ultimately leads to renal dysfunction. Salidroside (SAL) is considered to have broad anti-aging effects. However, the roles and mechanisms of SAL in aging-related renal fibrosis remain unclear. The study aimed to evaluate the protective effects and mechanisms of SAL in SAMP8 mice. SAMP8 mice were administered with SAL and Ferrostatin-1 (Fer-1) for 12 weeks. Renal function, renal fibrosis, and ferroptosis in renal tissue were detected. The results showed that elevated blood urea nitrogen (BUN) and serum creatinine (SCr) levels significantly decreased, serum albumin (ALB) levels increased, and mesangial hyperplasia significantly reduced in the SAL group. SAL significantly reduced transforming growth factor-β (TGF-β) and α-smooth muscle actin (α-sma) levels in SAMP8 mice. SAL treatment significantly decreased lipid peroxidation in the kidneys, and regulated iron transport-related proteins and ferroptosis-related proteins. These results suggested that SAL delays renal aging and inhibits aging-related glomerular fibrosis by inhibiting ferroptosis in SAMP8 mice.  相似文献   
118.
Xu  B.  Wu  C.  Jin  W. H.  Zhang  Y. P.  Fang  H.  Chao  Z. M. 《Crystallography Reports》2022,67(7):1187-1192
Crystallography Reports - The compound of fucosterol (C29H48O), an active phytosterol present in many edible marine algae, has been characterized by X-ray diffraction and extensive nuclear magnetic...  相似文献   
119.
超声药物透入疗法的临床应用进展   总被引:12,自引:0,他引:12       下载免费PDF全文
周万松 《应用声学》2001,20(1):6-10
本文介绍了超声药物透入疗法的临床应用进展,简要回顾了其发展历程,讨论与评价此种疗法的临床意义,提出了存在不足与今后的发展。  相似文献   
120.
应用显微傅里叶变换红外光谱技术原位分析雌性Hartley豚鼠胫骨关节软骨的化学组成。红外光谱测定包含三种月龄(1月、2月和3月)和3个软骨层次(表层、中层和深层)。结果表明,随着月龄的增加,表层和中层FTIR光谱的主要吸收峰峰位红移,深层吸收峰先红移后蓝移。软骨中胶原蛋白、核酸和蛋白多糖的红外光谱具有如下特征:峰强比I1 657/I1 548,I1 074/I1 548I1 074/I1 237在软骨表层和中层随月龄递降,而在软骨深层2月龄的比值最低。结果符合关节软骨在不同退变阶段化学成分的变化规律,且显微光谱成像技术转化的各月龄胫骨平台二维图像高度符合相应的病理描述。初步研究显示,显微FTIR技术可原位分析不同层次软骨组织的分子组成,能为研究软骨疾病的发病机理提供可靠信息。  相似文献   
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