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961.
Biodiesel production from rubber seed oil using poly (sodium acrylate) supporting NaOH as a water-resistant catalyst 总被引:1,自引:0,他引:1
Poly (sodium acrylate) supporting NaOH (NaOH/NaPAA) was prepared by in situ polymerization of aqueous solution of acrylic acid with an over-neutralization by adding excess of NaOH. NaOH/NaPAA presented a promising selectivity for water absorbency and good water retention with negligible swelling capacity in the organic solvents of methanol, glycerol, rubber seed oil methyl esters, and rubber seed oil. NaOH/NaPAA catalysts showed a basic strength of 15.0 < H_ < 18.4 and their basicity increased with the increase of the NaOH loading amount. NaOH/NaPAA catalysts exhibited almost the same catalytic activity in the transesterification of rubber seed oil with methanol under the optimized reaction conditions compared to conventional homogeneous NaOH catalyst. Furthermore, the functional absorbent/catalyst system presented a good water resistance in the transesterification which retained high catalytic activity when a water concentration in the reaction system was less than 2 wt.%. 相似文献
962.
Guiyang Hao Jian Zhou Yi Guo Michael A. Long Tiffani Anthony Jennifer Stanfield Jer-Tsong Hsieh Xiankai Sun 《Amino acids》2011,41(5):1093-1101
Non-invasive detection of prostate cancer or metastases still remains a challenge in the field of molecular imaging. In our
recent work of screening arginine- or lysine-rich peptides for intracellular delivery of a therapeutic agent into prostate
cancer cells, an arginine-rich cell permeable peptide (NH2GR11) was found with an unexpectedly preferential uptake in prostate cancer cell lines. The goal of this work was to develop this
peptide as a positron emission tomography (PET) imaging probe for specific detection of distant prostate cancer metastases.
The optimal length of arginine-rich peptides was evaluated by the cell uptake efficiency of three fluorescein isothiocyanate
(FITC)-tagged oligoarginines (NHGR9, NHGR11, and NHGR13) in four human prostate cell lines (LNCaP, PZ-HPV-7, DU145, and PC3). Of the three oligoarginines, NH2GR11 showed the highest cell uptake and internalization efficiency with its subcellular localization in cytosol. The biodistribution
of FITC-NHGR9, FITC-NHGR11, and FITC-NHGR13 performed in control nude mice displayed the unique preferential accumulation of FITC-NHGR11 in the prostate tissue. Further in vivo evaluation of FITC-NHGR11 in PC3 tumor-bearing nude mice revealed elevated uptake of this peptide in tumors as compared to other organs. In vivo pharmacokinetics
evaluated with 64Cu-labeled NH2GR11 showed that the peptide was rapidly cleared from the blood (t
1/2 = 10.7 min) and its elimination half-life was 17.2 h. The PET imaging specificity of 64Cu-labled NH2GR11 was demonstrated for the detection of prostate cancer in a comparative imaging experiment using two different human cancer
xenograft models. 相似文献
963.
Computational protein structure prediction remains a challenging task in protein bioinformatics. In the recent years, the importance of template-based structure prediction is increasing because of the growing number of protein structures solved by the structural genomics projects. To capitalize the significant efforts and investments paid on the structural genomics projects, it is urgent to establish effective ways to use the solved structures as templates by developing methods for exploiting remotely related proteins that cannot be simply identified by homology. In this work, we examine the effect of using suboptimal alignments in template-based protein structure prediction. We showed that suboptimal alignments are often more accurate than the optimal one, and such accurate suboptimal alignments can occur even at a very low rank of the alignment score. Suboptimal alignments contain a significant number of correct amino acid residue contacts. Moreover, suboptimal alignments can improve template-based models when used as input to Modeller. Finally, we use suboptimal alignments for handling a contact potential in a probabilistic way in a threading program, SUPRB. The probabilistic contacts strategy outperforms the partly thawed approach, which only uses the optimal alignment in defining residue contacts, and also the re-ranking strategy, which uses the contact potential in re-ranking alignments. The comparison with existing methods in the template-recognition test shows that SUPRB is very competitive and outperforms existing methods. 相似文献
964.
Lü S Luo Q Hao X Li X Ji L Zheng W Wang F 《Bioorganic & medicinal chemistry letters》2011,21(23):6964-6968
Six analogs of imatinib, an Abl kinase inhibitor clinically used as a first-line therapeutic agent for chronic myeloid leukaemia (CML), have been synthesized and characterized. And their potency as Abl kinase inhibitors have been screened by a robust virtual screening method developed based on the crystal structure (PDB code 2hyy) of Abl-imatinib complex using Surflex-Docking. The docking results are consistent with the inhibitory potency of the compounds characterized by MS method. And the H-bonds between imatinib analogs and Thr315 and Met318 residues in Abl kinase are shown to be crucial for achieving accurate poses and high binding affinities for the ATP-competitive kinase inhibitors. 相似文献
965.
Cushing TD Baichwal V Berry K Billedeau R Bordunov V Broka C Browner MF Cardozo M Cheng P Clark D Dalrymple S DeGraffenreid M Gill A Hao X Hawley RC He X Labadie SS Labelle M Lehel C Lu PP McIntosh J Miao S Parast C Shin Y Sjogren EB Smith ML Talamas FX Tonn G Walker KM Walker NP Wesche H Whitehead C Wright M Jaen JC 《Bioorganic & medicinal chemistry letters》2011,21(1):423-426
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKβ. In this Letter we document our efforts at further optimization of this series, culminating in 2 with submicromolar potency in a HWB assay and efficacy in a CIA mouse model. 相似文献
966.
Shi F Ding J Zhang S Hao WJ Cheng C Tu S 《Bioorganic & medicinal chemistry letters》2011,21(5):1554-1558
The substrate-controlled chemoselective synthesis of novel 5,6,7-triarylpyrido[2,3-d]pyrimidin-4-one derivatives has been successfully achieved via microwave-assisted three-component reactions of 2,6-diaminopyrimidin-4(3H)-one, aromatic aldehydes and 1,2-diphenylethanone. This approach has the prominent features of chemoselectivity, diasteroselectivity, atom economy, short reaction time, high yield as well as operational simplicity. Moreover, these novel compounds were subject to the test of in vitro cytotoxicity to carcinoma SW1116 and SGC7901 cells. Most of the tested compounds showed significant cytotoxicity to SW1116 cells and compound 4b exhibited more potent and efficacious cytotoxicity to SGC7901 cells than doxorubicin hydrochloride as positive control. 相似文献
967.
Peng H Liang Y Chen L Fu L Wang H He H 《Bioorganic & medicinal chemistry letters》2011,21(4):1102-1104
The synthesis and biological activity of 1,3-benzenedicarbonyl dithioureas are described. Bioassay results indicated that these compounds exhibited cytotoxicity against various cancer cells. For example, compounds 4a showed the best inhibition activities against KB and CNE2 with IC50 10.72 and 9.91 μM, respectively. 相似文献
968.
Zheng C Cao G Xia M Feng H Glenn J Anand R Zhang K Huang T Wang A Kong L Li M Galya L Hughes RO Devraj R Morton PA Rogier DJ Covington M Baribaud F Shin N Scherle P Diamond S Yeleswaram S Vaddi K Newton R Hollis G Friedman S Metcalf B Xue CB 《Bioorganic & medicinal chemistry letters》2011,21(5):1442-1446
We report the discovery of a potent, selective, and orally bioavailable dual CCR2 and CCR5 antagonist (3S,4S)-N-[(1R,3S)-3-isopropyl-3-({4-[4-(trifluoromethyl)pyridin-2-yl]piperazin-1-yl}carbonyl)cyclopentyl]-3-methoxytetrahydro-2H-pyran-4-amine (19). After evaluation in 28-day toxicology studies, compound 19 (INCB10820/PF-4178903) was selected as a clinical candidate. 相似文献
969.
Zapf CW Bloom JD Li Z Dushin RG Nittoli T Otteng M Nikitenko A Golas JM Liu H Lucas J Boschelli F Vogan E Olland A Johnson M Levin JI 《Bioorganic & medicinal chemistry letters》2011,21(15):4602-4607
An extension of our previously reported series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. Addition of a second methyl group to the tether provided analogs that show increased potency in binding as well as cell-proliferation assays and, more importantly, are stable toward microsomes. We wish to disclose the discovery of a macrocycle which showed impressive biomarker activity 24-h post dosing and which demonstrated prolonged exposure in tumors. When studied in a lung cancer xenograft model, the compound demonstrated significant tumor size reduction. 相似文献
970.
小型生物反应器内人参不定根的人参皂苷累积 总被引:2,自引:0,他引:2
对小型生物反应器(3~10 L)培养人参不定根的生长和人参皂苷(Rg1、Re、Rb1)的累积规律,以及蔗糖浓度、初始接种量对其生长和人参皂苷累积的影响进行研究。结果表明:小型生物反应器内人参不定根的最佳收获周期为7周。初始接种量和蔗糖浓度影响生物反应器内人参不定根的生长和人参皂苷的累积,20或40 g/L蔗糖对人参不定根的生长和人参皂苷的累积优于60 g/L蔗糖;5和10 L生物反应器内最佳初始接种量分别为15和30g,其不定根的生长量分别为9.29和19.17 g,人参皂苷含量分别为5.16和4.58 mg/g。生物反应器内培养7周的人参与栽培4年的人参相比,人参皂苷Rg1和Re含量相差不大,但栽培人参中Rb1的含量远高于生物反应器中所培养的人参不定根。 相似文献