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51.
Jones NA Nepogodiev SA MacDonald CJ Hughes DL Field RA 《The Journal of organic chemistry》2005,70(21):8556-8559
Described herein is the synthesis of 3-C-carboxy-5-deoxy-L-xylose (aceric acid), a rare branched-chain sugar found in the complex pectic polysaccharide rhamnogalacturonan-II. The key synthetic step in the construction of aceric acid was the stereoselective addition of 2-trimethylsilyl thiazole to 5-deoxy-1,2-O-isopropylidene-alpha-L-erythro-pentofuran-3-ulose (2), which was prepared from L-xylose. The thiazole group was efficiently converted into the required carboxyl group via conventional transformations. Aceric acid was also synthesized by dihydroxylation of a 3-C-methylene derivative of 2 followed by oxidation of the resulting hydroxylmethyl group. The C-2 epimer of aceric acid was also synthesized using thiazole addition chemistry, starting from L-arabinose. 相似文献
52.
53.
Ian Hamerton John R. Jones David C. Povey Gallienus W. Smith John M. Barton 《Journal of chemical crystallography》1992,22(1):101-108
The structure of the title compound (I) was determined by direct methods using MoK diffractometer data, and refined by full-matrix least squares toR=0.066 for 1536 reflections (I3 (I)). The structure shows a central tetrahedral carbon atom surrounded by two methyl and two 3-allyl-4-cyanatophenyl groups. The geometry of the cyanato group in this molecule compares well with those in 2,2-bis(4-cyanatophenyl)isopropylideneII) and 4-chloro-3,5-dimethyl-phenylcyanate (III), the only other examples of organic compounds bearing the cyanato moiety in the Cambridge Crystallographic Database (V.3). 相似文献
54.
A new extrapolation procedure which encompasses Aitken's 2 processand extends to higher orders of convergence is presented. Thenew extrapolation yields information as to whether an algorithmis converging or diverging as well as a new approximation tothe solution point. The new extrapolation technique is comparedwith existing higher order extrapolation techniques. The valueof the new extrapolation is demonstrated analytically and empirically. 相似文献
55.
Simplified electrochemical atom transfer radical polymerization (seATRP) using CuII–N-propyl pyridineimine complexes (CuII(NPPI)2) is reported for the first time. In aqueous solution, using oligo(ethylene glycol) methyl ether methacrylate (OEGMA), standard electrolysis conditions yield POEGMA with good control over molecular weight distribution (Đm < 1.35). Interestingly, the polymerizations are not under complete electrochemical control, as monomer conversion continues when electrolysis is halted. Alternatively, it is shown that the extent and rate of polymerization depends upon an initial period of electrolysis. Thus, it is proposed that seATRP using CuII(NPPI)2 follows an electrochemically-triggered, rather than electrochemically mediated, ATRP mechanism, which distinguishes them from other CuIIL complexes that have been previously reported in the literature.Simplified electrochemical atom transfer radical polymerization (seATRP) using CuII-pyridineimine complexes is reported and follows a previously unreported electrochemically triggered mechanism. 相似文献
56.
Lawan Ly Xiaoqian Cheng Saravana R. K. Murthy Olivia Z. Jones Taisen Zhuang Steven Gitelis Alan T. Blank Aviram Nissan Mohammad Adileh Matthew Colman Michael Keidar Giacomo Basadonna Jerome Canady 《Molecules (Basel, Switzerland)》2022,27(13)
Soft tissue sarcomas (STS) are a rare and highly heterogeneous group of solid tumors, originating from various types of connective tissue. Complete removal of STS by surgery is challenging due to the anatomical location of the tumor, which results in tumor recurrence. Additionally, current polychemotherapeutic regimens are highly toxic with no rational survival benefit. Cold atmospheric plasma (CAP) is a novel technology that has demonstrated immense cancer therapeutic potential. Canady Cold Helios Plasma (CHCP) is a device that sprays CAP along the surgical margins to eradicate residual cancer cells after tumor resection. This preliminary study was conducted in vitro prior to in vivo testing in a humanitarian compassionate use case study and an FDA-approved phase 1 clinical trial (IDE G190165). In this study, the authors evaluate the efficacy of CHCP across multiple STS cell lines. CHCP treatment reduced the viability of four different STS cell lines (i.e., fibrosarcoma, synovial sarcoma, rhabdomyosarcoma, and liposarcoma) in a dose-dependent manner by inhibiting proliferation, disrupting cell cycle, and inducing apoptosis-like cell death. 相似文献
57.
Arjun H. Banskota Sean M. Tibbetts Alysson Jones Roumiana Stefanova Joerg Behnke 《Molecules (Basel, Switzerland)》2022,27(15)
Hemp (Cannabis sativa L.) processing by-products (hemp cake and hemp seed hulls) were studied for their protein content, extraction of protein isolates (PIs), and their in vitro protein digestibility (IVPD). Crude protein contents of hemp cake and hemp seed hulls were 30.4% and 8.6%, respectively, calculated based on generalized N-to-P conversion factor (N × 5.37). Extraction efficiency of PIs from defatted biomass ranged from 56.0 to 67.7% with alkaline extraction (0.1 M NaOH) followed by isoelectric precipitation (1.0 M HCl). Nitrogen analysis suggested that the total protein contents of PIs extracted using three different alkaline conditions (0.5 M, 0.1 M, and pH 10.0 with NaOH) were >69.7%. The hemp by-product PIs contained all essential amino acids (EAAs) required for fish with leucine, valine, and phenylalanine belonging to the five dominant amino acids. Overall, glutamate was the dominant non-EAA followed by aspartate. Coomassie staining of an SDS-PAGE gel revealed strong presence of the storage protein edestin. High IVPD of >88% was observed for PIs extracted from hemp seeds and by-products when evaluated using a two-phase in vitro gastric/pancreatic protein digestibility assay. PIs extracted from by-products were further tested for their antioxidant activities. The tested PIs showed dose-dependent DPPH radical scavenging activity and possessed strong ORAC values > 650 μM TE/g. 相似文献
58.
David E. Mery Amanda J. Compadre Paola E. Ordez Edward J. Selvik Vladimir Morocho Jorge Contreras Omar Malagn Darin E. Jones Philip J. Breen Michael J. Balick Flavio G. Gaudio Monica L. Guzman Cesar M. Compadre 《Molecules (Basel, Switzerland)》2022,27(9)
A method to identify anticancer compounds in plants was proposed based on the hypothesis that these compounds are primarily present in plants to provide them with an ecological advantage over neighboring plants and other competitors. According to this view, identifying plants that contain compounds that inhibit or interfere with the development of other plant species may facilitate the discovery of novel anticancer agents. The method was developed and tested using Magnolia grandiflora, Gynoxys verrucosa, Picradeniopsis oppositifolia, and Hedyosmum racemosum, which are plant species known to possess compounds with cytotoxic activities. Plant extracts were screened for growth inhibitory activity, and then a thin-layer chromatography bioautography assay was conducted. This located the major antileukemic compounds 1, 2, 4, and 5 in the extracts. Once the active compounds were located, they were extracted and purified, and their structures were determined. The growth inhibitory activity of the purified compounds showed a significant correlation with their antileukemic activity. The proposed approach is rapid, inexpensive, and can easily be implemented in areas of the world with high biodiversity but with less access to advanced facilities and biological assays. 相似文献
59.
S. M. Jones A. Amran S. E. Friberg B. Katz G. C. Farrington 《Journal of Dispersion Science and Technology》2013,34(1):97-117
ABSTRACT Materials which display ionic conductivity were produced by the sol-gel and microemulsion-gel methods. The charging and discharging characteristics were investigated and it was found that a single ionic species was responsible for the conduction, the ionic species being residual protons from the initial component mixture. The complex impedence of various samples was measured and the ionic conductivities ranged in value from 9 × 10?8 to 1 × 10?5 ohm?1 cm?1. An Arrhemius plot for a microemulsion-gel revealed that the energy of activation was 0.15 eV. 相似文献
60.
The organocatalysed asymmetric hydrosilylation of a number of N-aryl and alkyl β-substituted enamino esters proceeds in generally good yield and enantioselectivity. Crucial to obtaining high yield and selectivity was the addition of benzoic acid as an additive and under these conditions, both N-alkyl and N-aryl substituents were well tolerated. β-Aryl and alkyl substituents were evaluated and a model proposed to account for the experimental observations based upon enamine tautomerisation and conformational preferences of the reactive ketimine intermediate. 相似文献