Synthesis of Regioselectively Acylated Quercetin Analogues with Improved Antiplatelet Activity

The aim of the present study was to report on a complete synthetic approach, namely benzylation-hydrolysis-acylation-hydrogenation, to the synthesis of regioselectively acylated quercetin analogues using low-cost rutin as a starting material. Three quercetin analogues, quercetin-3-O-propionate (Q-pr), quercetin-3-O-butyrate (Q-bu) and quercetin-3-O-valerate (Q-va), containing 3-, 4- and 5-carbon aliphatic acyl chains, respectively, were synthesized and characterized with 1H nuclear magnetic resonance (NMR), 13C NMR and mass spectrometry. Compared with quercetin, all three analogues exhibited improved lipophilicity. The lipophilicity of the analogue increased with increasing acyl chain length. Q-va exhibited the highest lipophilicity among the three analogues, but a lower water solubility compared with quercetin. By contrast, Q-pr and Q-bu exhibited 8.2- and 4.7-fold higher water solubility compared with quercetin, respectively. The in vitro and in vivo studies demonstrated that Q-pr and Q-bu were more effective whereas Q-va was less effective in inhibiting platelet aggregation compared with quercetin. These results indicated that the water solubility and the lipophilicity of the analogues must be improved in order to achieve higher antiplatelet activity, and an optimal acyl chain length is crucial for the synthesized quercetin analogues to be more effective

Conceptual Study and Performance Analysis of Tandem Dual-Antenna Spaceborne SAR Interferometry

Multi-baseline synthetic aperture radar interferometry (MB-InSAR), capable of mapping 3D surface model with high precision, is able to overcome the ill-posed problem in the single-baseline InSAR by use of the baseline diversity. Single pass MB acquisition with the advantages of high coherence and simple phase components has a more practical capability in 3D reconstruction than conventional repeat-pass MB acquisition. Using an asymptotic 3D phase unwrapping (PU), it is possible to get a reliable 3D reconstruction using very sparse acquisitions but the interferograms should follow the optimal baseline design. However, current spaceborne SAR system doesn't satisfy this principle, inducing more difficulties in practical application. In this article, a new concept of Tandem Dual-Antenna SAR Interferometry (TDA-InSAR) system for single-pass reliable 3D surface mapping using the asymptotic 3D PU is proposed. Its optimal MB acquisition is analyzed to achieve both good relative height precision and flexible baseline design. Two indicators, i.e., expected relative height precision and successful phase unwrapping rate, are selected to optimize the system parameters and evaluate the performance of various baseline configurations. Additionally, simulation-based demonstrations are conducted to evaluate the performance in typical scenarios and investigate the impact of various error sources. The results indicate that the proposed TDA-InSAR is able to get the specified MB acquisition for the asymptotic 3D PU, which offers a feasible solution for single-pass 3D SAR imaging.Comment: 16 pages, 20 figure

Data for High-Throughput Estimation of Specific Activities of Enzyme/Mutants in Cell Lysates Through Immunoturbidimetric Assay of Proteins

Data in this article are associated with the research article “Highthroughput estimation of specific activities of enzyme/mutants in cell lysates through immunoturbidimetric assay of proteins” (Yang et al., 2017) [1]. This article provided data on how to develop an immunoturbidimetric assay (ITA) of enzyme/mutants as proteins in cell lysates in high-throughput (HTP) mode together with HTP assay of their activities to derive their specific activities in cell lysates for comparison, with Pseudomonas aeruginosa arylsulfatase (PAAS) and Bacillus fastidious uricase (BFU) plus their mutants as models. Data were made publicly available for further analyses