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1.
Fatty acid vesicles (FAVs) have hollow core-shell structures similar to those of liposomes, and the building block fatty acids are naturally abundant, green, and safe; therefore, FAVs have potential applications in embedding/release systems. However, FAVs are pH sensitive, and the pH window for FAV formation is narrow and biologically unsuitable. These disadvantages prevent FAVs from being used in domestic chemicals and externally applied agents. In this study, a green and safe nonionic surfactant, alkyl polyglucoside (APG), was blended with a model fatty acid conjugated linoleic acid (CLA) to help the latter to form FAVs in a biologically suitable pH window. The experimental results showed that mixing CLA with APG changed the pH window from 8.0-9.0 for CLA to 6.0-8.0 for CLA-APG; this matches the biologically suitable pH range. Methods for improving the pH dependence of FAV formation and the pH-sensitive properties of FAVs were investigated. 相似文献
2.
A new class of photochromic diarylethenes bearing pyrrole and thiophene units with different length of alkyl chains at 2-position of thiophene rings have been synthesized. Their characteristics, including photochromism and fatigue resistance were investigated systematically, and each diarylethene derivative showed good photochromic properties whether in solution or in PMMA films. The alkyl group moiety was connected directly to the central cyclopentene ring as a heteroaryl unit and availably participated in photoisomerization reaction. And some properties, for example, the conversion ratio in the photostationary state(PSS) and the absorption coefficient of the ring-closed isomers in acetonitrile were significantly affected by the alkyl chain length. The results revealed that substituents of alkyl chain played an important role in the photoisomerization process of diarylethenes. 相似文献
3.
An efficient catalyst-free, alternative method for the C–N bond formation reaction of alkyl electrophiles using formamides as the N-sources was achieved under mild conditions. The reaction possesses the advantages of a broad range of substrates scope and wide functional group tolerance. It should also be noted that this process was performed using the environmentally benign water as the sole solvent, and high yield can also be achieved in ten-gram scale. 相似文献
4.
Identification,control strategies,and analytical approaches for the determination of potential genotoxic impurities in pharmaceuticals: A comprehensive review 下载免费PDF全文
Ambavaram Vijaya Bhaskar Reddy Jafariah Jaafar Khalid Umar Zaiton Abdul Majid Azmi Bin Aris Juhaizah Talib Gajulapalle Madhavi 《Journal of separation science》2015,38(5):764-779
Potential genotoxic impurities in pharmaceuticals at trace levels are of increasing concern to both pharmaceutical industries and regulatory agencies due to their possibility for human carcinogenesis. Molecular functional groups that render starting materials and synthetic intermediates as reactive building blocks for small molecules may also be responsible for their genotoxicity. Determination of these genotoxic impurities at trace levels requires highly sensitive and selective analytical methodologies, which poses tremendous challenges on analytical communities in pharmaceutical research and development. Experimental guidance for the analytical determination of some important classes of genotoxic impurities is still unavailable in the literature. Therefore, the present review explores the structural alerts of commonly encountered potential genotoxic impurities, draft guidance of various regulatory authorities in order to control the level of impurities in drug substances and to assess their toxicity. This review also describes the analytical considerations for the determination of potential genotoxic impurities at trace levels and finally few case studies are also discussed for the determination of some important classes of potential genotoxic impurities. It is the authors’ intention to provide a complete strategy that helps analytical scientists for the analysis of such potential genotoxic impurities in pharmaceuticals. 相似文献
5.
Linjun Qi Ming Dong Jinlong Qian Shuling Yu Prof. Xiaofeng Tong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(3):e202215397
Reductive elimination of alkyl−PdII−O is a synthetically useful yet underdeveloped elementary reaction. Here we report that the combination of an H-bonding donor [PyH][BF4] and AgNO3 additive under toluene/H2O biphasic system can enable such elementary step to form alkyl nitrate. This results in the Pd0-catalyzed asymmetric carbonitratations of (Z)-1-iodo-1,6-dienes with (R)-BINAP as the chiral ligand, affording alkyl nitrates up to 96 % ee. Mechanistic studies disclose that the reaction consists of oxidative addition of Pd0 catalyst to vinyl iodide, anion ligand exchange between I− and NO3−, alkene insertion and SN2-type alkyl−PdII−ONO2 reductive elimination. Evidences suggest that H-bonding interaction of PyH⋅⋅⋅ONO2 can facilitate dissociation of O2NO− ligand from the alkyl−PdII−ONO2 species, thus enabling the challenging alkyl−PdII−ONO2 reductive elimination to be feasible. 相似文献
6.
GAO Jie MENG Ye ZHAO Weiwei JIANG Daofa JIN Yanmei ZHENG Jun YANG Xinan MA Peihua 《高等学校化学研究》2021,37(3):674-678
The host-guest interactions between cyclopentanocucurbit-[6]uril(CyP6Q[6]) as host and six alkyl imidazolium hydrochloride as guests(g1, g2, g3, g4, g5, and g6) have been studied by various techniques, such as 1H NMR spectroscopy, isothermal titration calorimetry, mass spectrometry, and single-crystal X-ray diffraction analysis. The experimental results showed that CyP6Q[6] formed 1:1 inclusion complexes with each of guests g1-g6. The part of the guest entered the cavity of CyP6Q[6] changes as the alkyl chain increases in length. It can be seen that the length of the alkyl chain plays a key role in determining the mode of host-guest interactions. 相似文献
7.
研究了端基烯烃和醛肟在氧化剂过硫酸氢钾和催化量碘代烷烃作用下的[3+2]环合反应,合成了一系列具有良好产率及区域选择性的3,5-二取代异噁唑啉化合物.反应中,碘代烷烃先经过氧化分解产生了活泼的次碘酸,再依次与醛肟和烯烃经亲电加成反应生成五元杂环碘代中间体,该中间体通过消除反应得到3,5-二取代异噁唑啉化合物.考察了反应条件的影响,提出了可能的反应机理,为合成3,5-二取代异噁唑啉化合物提供了新方法. 相似文献
8.
José E. Báez Ángel Marcos-Fernández 《International Journal of Polymer Analysis and Characterization》2015,20(7):637-644
The biodegradable aliphatic oligoesters polyglycolide (PGA), poly(L-lactide) (PLLA), and poly(?-caprolactone) (PCL) with similar number-average molecular weight Mn values but different linear alkyl end groups [CH3?[CH2?CH2]m?CH2?] were compared in terms of their physical properties, parameters such as melting temperature (Tm), crystallinity (xi), long period (L), and lamella thickness (D). They were analyzed by DSC and SAXS. The effect of a longer and nonpolar alkyl end group such as docosyl [CH3?[CH2?CH2]10?CH2?] on the long period (L) was more evident for PCL because it was the most nonpolar species in the family of oligoesters analyzed. 相似文献
9.
《Journal of Coordination Chemistry》2012,65(12):2075-2087
Nickel phthalocyanine (NiPc, 1) periphery has been decorated by alkyl chains of varying chain length via [1,3,4]-oxadiazole moiety (NiPcs 3a–3f). All the newly synthesized compounds NiPcs 3a–3d have been completely characterized by elemental analysis, FT-IR, solid-state UV-Vis, and solid-state 13C NMR spectroscopy, in addition to X-ray diffraction, scanning electron microscopy, and thermal analysis. The effect of chain length in the NiPc periphery on electronic absorption and DC electrical conductivity has been investigated. 相似文献
10.
《Journal of Coordination Chemistry》2012,65(8):1396-1404
The synthesis and characterization of 1-phenyl-3-alkyl-substituted carbene precursors that were prepared from 1-phenyl substituted benzimidazole and various alkyl halides are reported. The new benzimidazolium salts (1a–e) were characterized by 1H NMR, 13C NMR, FT-IR spectroscopic methods and elemental analyses. New in situ generated palladium-benzimidazolium complexes were tested for catalytic activity in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions. 相似文献