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141.
Anita Toth Eszter Riethmuller Krisztina Vegh Agnes Alberti Szabolcs Beni Agnes Kery 《Natural product research》2018,32(17):2058-2061
Quantitative phytochemical characterisation of the chief flavonoid aglycones in the hydrolysed Lysimachia extracts revealed the dominance of kaempferol, quercetin and myricetin in L. vulgaris, L. nummularia, L. punctata, L. christinae, L. ciliata and L. clethroides, respectively. Due to the significant radical scavenging capacity of the samples, the contribution of the individual aglycones to the total antioxidant activity became of interest. Therefore, a HPLC method coupled to pre-column DPPH scavenging assay was developed. Differences in the six Lysimachia species’ phenolic composition regarding their participation to the antioxidant activity were revealed. The participation of the three investigated flavonoids to the radical quenching activity was the highest (91.2%) in the L. vulgaris sample, the lowest in L. christinae sample with 29.6%. In L. vulgaris sample, the 76.3% contribution of quercetin to the scavenger capacity was the highest peak area decrement ratio among the investigated samples. 相似文献
142.
Aoife M. Foley Declan P. Gavin Rebecca E. Deasy Sinéad E. Milner Thomas S. Moody Kevin S. Eccles Simon E. Lawrence Anita R. Maguire 《Tetrahedron》2018,74(13):1435-1443
Efforts to combine the intramolecular nitroaldol reaction with lipase-catalysed resolution of the resulting nitroaldol adduct in a one-pot dynamic kinetic resolution (DKR) are described. Significant challenges were encountered in the combination of the two systems. trans-2-Methyl-2-nitrocyclohexyl acetate (±)-3b was isolated in excellent enantiopurity (>98% ee) via a sequential DKR sequence where the lipase-mediated resolution and base-mediated interconversion of 2-methyl-2-nitrocyclohexanol 2 were effected alternately, demonstrating the feasibility of this approach initially. Further work showed, for the first time, evidence that a DKR-type system is possible for 2. Reaction engineering allowed the design of a sequential one-pot reaction system which furnished the products with excellent enantioselectivity, and good diastereoselectivity. 相似文献
143.
Emilia Grodzka Marta Nieciecka Krzysztof Winkler 《Journal of Solid State Electrochemistry》2008,12(3):215-223
The stability of C60 and palladium two-component films, C60/Pd, has been investigated. The effect of different polymerization conditions on the electrochemical stability of the film
upon prolonged potential cycling has been studied. Stable voltammetric behavior was observed for polymers formed at potentials
less negative than the potential of third C60 reduction step. The incorporation of palladium particles into the structure of C60/Pd polymers increases the polymer stability. The C60/Pd films are doped with supporting electrolyte cations during reduction. The size of these cations is a crucial factor in
determining the stability of the film. A strong solvent effect on the potential stability of the film was also observed. The
wildest range of stable voltammetric properties was found for acetonitrile and N,N-dimethylformamide. No effect of the temperature on the film stability was observed. The results reported in this work allow
for the determination of the optimal conditions for the formation of stable C60/Pd films. 相似文献
144.
Investigation of the reaction of α-thioamides, α-esters and α-nitriles with NBS and NCS is described. The scope of this stereoselective oxidative transformation to the β-haloacrylamides, β-acrylates and β-acrylonitriles has been determined. A mechanistic rationale to explain the observed differences in reactivity between the amide, ester and nitrile series is proposed. 相似文献
145.
Mohamed E Abdul-Rahman PS Doustjalali SR Chen Y Lim BK Omar SZ Bustam AZ Singh VA Mohd-Taib NA Yip CH Hashim OH 《Electrophoresis》2008,29(12):2645-2650
A 35 kDa glycoprotein whose abundance was previously demonstrated to be enhanced in sera of patients with endometrial adenocarcinoma (n = 12), was isolated from pooled sera of three of the cancer patients using champedak galactose-binding lectin affinity chromatography in the present study. Subjecting it to 2-DE and MS/MS, the glycoprotein was identified as the O-glycosylated fragment of inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4). When compared to control sera (n = 17), expression of the 35 kDa ITIH4 cleavage fragment was demonstrated to be significantly enhanced in sera of patients with breast carcinoma (n = 10), epithelial ovarian carcinoma (n = 10), and germ cell ovarian carcinoma (n = 10) but not in patients with nasopharyngeal carcinoma (n = 13) and osteosarcoma (n = 7). The lectin-based electrophoretic bioanalytical method adopted in the present study may be used to assess the physiological relevance of ITIH4 fragmentation and its correlation with different malignancies, their stages and progression. 相似文献
146.
Bourhim M Rajendran A Ramos Y Srikrishnan T Sulkowski E 《Journal of chromatographic science》2008,46(6):574-576
An investigation of the binding of native and recombinant human serum albumin and bovine serum albumin on three thiophilic gels, PyS, 2S, and 3S was performed. In addition to these proteins, we studied serum albumins from several species such as goat, rabbit, guinea pig, rat, hamster, baboon, and pig. Our results reveal that recombinant human serum albumin (rHSA) binds completely to PyS whereas native human serum albumin and bovine serum albumin bind only partially to PyS. The binding affinities of rHSA, human serum albumin and bovine serum albumin to 2S and 3S gels are less than their binding to PyS. Serum albumins from goat, rabbit, guinea pig, rat, hamster, baboon, and pig bind much stronger to 3S gel than human and bovine serum albumins. The binding of pig and hamster serum albumins is stronger than that of rat, goat, baboon, and rabbit. 相似文献
147.
Behrouz Notash Hamid Reza Khavasi Vahid Amani Anita Abedi 《Journal of organometallic chemistry》2008,693(24):3553-3557
Two novel organometallic complex of 2,2′-dimethyl-4,4′-bithiazole (dm4bt) ligand (L) with formula [Tl(dm4bt)2(NO3)(H2O)] (1) and [Tl(dm4bt)2(NO3)(DMSO)] (2) have been synthesized and structurally characterized by elemental analysis, FT-IR, 1H NMR spectra and X-ray crystallography. These complexes also display the first transoid conformation in bithiazole ligands in which C-H bond activation in bithiazole ring is observed with Tl(III) ion. 相似文献
148.
The lantibiotic haloduracin consists of two posttranslationally processed peptides, Halalpha and Halbeta, which act in synergy to provide bactericidal activity. An in vitro haloduracin production system was used to examine the biological impact of disrupting individual thioether rings in each peptide. Surprisingly, the Halalpha B ring, which contains a highly conserved CTLTXEC motif, was expendable. This motif has been proposed to interact with haloduracin's predicted target, lipid II. Exchange of the glutamate residue in this motif for alanine or glutamine completely abolished antibacterial activity. This study also established that Halalpha-Ser26 and Halbeta-Ser22 escape dehydration, requiring revision of the Halbeta structure previously proposed. Extracellular proteases secreted by the producer strain can remove the leader peptide, and the Halalpha cystine that is dispensable for bioactivity protects Halalpha from further proteolytic degradation. 相似文献
149.
Campbell CD Duguet N Gallagher KA Thomson JE Lindsay AG O'Donoghue AC Smith AD 《Chemical communications (Cambridge, England)》2008,(30):3528-3530
Cascade reaction sequences incorporating N-heterocyclic carbene-based organocatalysis have been developed that allow the direct preparation of a range of (+/-)-4-phenoxycarbonylazlactones in good isolated yields (66-84%) from the corresponding N-p-anisoyl amino acids. 相似文献
150.
A Single Methylene Group in Oligoalkylamine‐Based Cationic Polymers and Lipids Promotes Enhanced mRNA Delivery 下载免费PDF全文
Anita Jarzębińska Dr. Tamara Pasewald Jana Lambrecht Olga Mykhaylyk Linda Kümmerling Dr. Philipp Beck Dr. Günther Hasenpusch Priv.‐Doz. Dr. Carsten Rudolph Prof. Dr. Christian Plank Dr. Christian Dohmen 《Angewandte Chemie (International ed. in English)》2016,55(33):9591-9595
The development of chemically modified mRNA holds great promise as a new class of biologic therapeutics. However, the intracellular delivery and endosomal escape of mRNA encapsulated in nanoparticles has not been systematically investigated. Here, we synthesized a diverse set of cationic polymers and lipids from a series of oligoalkylamines and subsequently characterized their mRNA delivery capability. Notably, a structure with an alternating alkyl chain length between amines showed the highest transfection efficiency, which was linked to a high buffering capacity in a narrow range of pH 6.2 to 6.5. Variation in only one methylene group resulted in enhanced mRNA delivery to both the murine liver as well as porcine lungs after systemic or aerosol administration, respectively. These findings reveal a novel fundamental structure–activity relationship for the delivery of mRNA that is independent of the class of mRNA carrier and define a promising new path of exploration in the field of mRNA therapeutics. 相似文献