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141.
Dr. Mara Florea Dr. Srikanth Kudithipudi Dr. Ana Rei María José González‐Álvarez Prof. Dr. Albert Jeltsch Prof. Dr. Werner M. Nau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3521-3528
The demand for practical and convenient enzyme assays for histone lysine methyltransferases (HKMTs) emerges along with the rapid development of this young class of enzymes. A supramolecular reporter pair composed of p‐sulfonatocalix[4]arene (CX4) and the fluorescent dye lucigenin (LCG) has been used to monitor enzymatic trimethylation of lysine residues in peptide substrates. The assay affords a switch‐ON fluorescence response and operates in a continuous, real‐time, and label‐free fashion. The underlying working principle relies on the higher affinity of the macrocycle towards the trimethylated product of the enzymatic reaction as compared to the substrate, which allows the assay to be carried out in the product‐selective mode. The final product incorporates a trimethylammonium moiety, a known high‐affinity binding motif for CX4. Two substrates corresponding to the H3 N‐terminal tail, namely, S2 (RTKQTA RKSTG GKAP) and S6 (QTA RKSTG GS), were selected as model compounds for methylation with the Neurospora crassa Dim‐5 enzyme and investigated by the newly developed supramolecular tandem HKMTs assay. Only the longer substrate S2 underwent methylation in solution. The potential of the assay for inhibitor screening was demonstrated by means of inhibition studies with 1,10‐phenanthroline to afford an inhibition constant of (70±20) μM . 相似文献
142.
Synthesis and Characterization of Donor–π‐Acceptor‐Based Porphyrin Sensitizers: Potential Application of Dye‐Sensitized Solar Cells 下载免费PDF全文
Mareedu Sreenivasu Akira Suzuki Dr. Mitsuhiro Adachi Challuri Vijay Kumar Dr. Bingi Srikanth S. Rajendar Dasa Rambabu Dr. Rangaraju Satish Kumar P. Mallesham Dr. N. Vijaya Bhaskar Rao Dr. M. Suresh Kumar Dr. P. Y. Reddy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):14074-14083
New porphyrin sensitizers based on donor–π‐acceptor (D‐π‐A) approach have been designed, synthesized, characterized by various spectroscopic techniques and their photovoltaic properties explored. N,N′‐Diphenylamine acts as donor, the porphyrin is the π‐spacer, and either carboxylic acid or cyanoacryclic acid acts as acceptor. All compounds were characterized by using 1H NMR spectroscopy, ESI‐MS, UV–visible emission spectroscopies as well as electrochemical methods. The presence of aromatic groups between porphyrin π‐plane and acceptor group push the absorption of both Soret and Q‐bands of porphyrin towards the red region. The electrochemical properties suggests that LUMO of these sensitizers above the TiO2 conduction band. Finally, the device was fabricated using liquid redox electrolyte (I?/I3?) and its efficiency was compared with that of a leading sensitizer. 相似文献
143.
Abbas A Tian L Kattumenu R Halim A Singamaneni S 《Chemical communications (Cambridge, England)》2012,48(11):1677-1679
The ability to stop the self-assembly of gold nanocrystals at a desired stage of the process provides new leverage to understand and control the dynamics of self-assembly. Herein, competitive ligands are used to unfavor the interaction of the cross-linker with the gold surface and terminate the growth reaction of gold nanoparticles and nanorod chains. 相似文献
144.
A series of 2-(p-fluorobenzyl)-3-aryl-6-methoxybenzofurans has been prepared in good yields in a two-step sequence from the corresponding benzylidencoumaranones (aurones). 相似文献
145.
Bharadwaj R. Prabhala Mahesh V. Panchagnula Srikanth Vedantam 《Colloid and polymer science》2013,291(2):279-289
In this paper, we study equilibrium three-dimensional shapes of drops on hysteretic surfaces. We develop a function coupled with the publicly available surface energy minimization code Surface Evolver to handle contact angle hysteresis. The function incorporates a model for the mobility of the triple line into Surface Evolver. The only inputs to the model are the advancing and receding contact angles of the surface. We demonstrate this model’s versatility by studying three problems in which parts of the triple line advance while other parts either recede or remain stationary. The first problem focuses on the three-dimensional shape of a static pendant drop on a vertical surface. We predict the finite drop volume when impending sliding motion is observed. In the second problem, we examine the equilibrium shapes of coalescing sessile drops on hysteretic surfaces. Finally, we study coalescing puddles in which gravity plays a leading role in determining the equilibrium puddle shape along with hysteresis. 相似文献
146.
G. Srikanth D. V. N. Srinivas Rao P. Badarinadh Gupta P. Lavanya Aminul Islam 《合成通讯》2013,43(9):1359-1366
A new and efficient process through a new intermediate, (2E)-2-cyano-3-(3,4-dihydroxy-5-nirtrophenyl)prop-2-enoic acid 15, has been described for preparing substantially pure entacapone 1. This new intermediate 15 was prepared by Knoevenagel condensation of 3,4-dihydroxy-5-nitrobenzaldehyde 2 with 2-cyanoacetic acid 14 and was further condensed with diethylamine to get pure entacapone 1. Some of the important process-related impurities of entacapone (17, 18, 19, and 20) were also prepared easily from this intermediate 15. 相似文献
147.
‘Caging’ and ‘uncaging’ bioactive substrates are key techniques in studying a wide variety of biological processes. In the present study, two-types of novel caged glutamates with a two-photon absorption (TPA) core, that is, π-extended coumarin, were synthesized and their photochemical release of glutamate was analyzed. The high yields of glutamate (>92%) were observed in the photolysis of compounds 1 and 10, respectively. 相似文献
148.
Nur Hanisah Mustafa Mahendran Sekar Shivkanya Fuloria M. Yasmin Begum Siew Hua Gan Nur Najihah Izzati Mat Rani Subban Ravi Kumarappan Chidambaram Vetriselvan Subramaniyan Kathiresan V. Sathasivam Srikanth Jeyabalan Subasini Uthirapathy Sivasankaran Ponnusankar Pei Teng Lum Vijay Bhalla Neeraj Kumar Fuloria 《Molecules (Basel, Switzerland)》2022,27(6)
Sarsasapogenin is a natural steroidal sapogenin molecule obtained mainly from Anemarrhena asphodeloides Bunge. Among the various phytosteroids present, sarsasapogenin has emerged as a promising molecule due to the fact of its diverse pharmacological activities. In this review, the chemistry, biosynthesis and pharmacological potentials of sarsasapogenin are summarised. Between 1996 and the present, the relevant literature regarding sarsasapogenin was obtained from scientific databases including PubMed, ScienceDirect, Scopus, and Google Scholar. Overall, sarsasapogenin is a potent molecule with anti-inflammatory, anticancer, antidiabetic, anti-osteoclastogenic and neuroprotective activities. It is also a potential molecule in the treatment for precocious puberty. This review also discusses the metabolism, pharmacokinetics and possible structural modifications as well as obstacles and opportunities for sarsasapogenin to become a drug molecule in the near future. More comprehensive preclinical studies, clinical trials, drug delivery, formulations of effective doses in pharmacokinetics studies, evaluation of adverse effects and potential synergistic effects with other drugs need to be thoroughly investigated to make sarsasapogenin a potential molecule for future drug development. 相似文献
149.
Ashok Arasappan Srikanth Venkatraman Angela I. Padilla Wanli Wu Tao Meng Yan Jin Jesse Wong Andrew Prongay Viyyoor Girijavallabhan F. George Njoroge 《Tetrahedron letters》2007,48(36):6343-6347
A practical and efficient route toward synthesis of amino acid derivatives containing β-quaternary center has been developed using diastereoselective Strecker reaction. The method was employed for preparation of >100 g of β-methylcyclohexyl glycine derivative, 21. Incorporation of some of the hindered amino acid derivatives at the P3 position resulted in potent HCV NS3 serine protease inhibitors. 相似文献
150.
By making a combination of both point contact and barrier type tunnel junctions on a single sample of the highT
c superconductor BSCCO (2212) single crystal, we have shown that as the tunneling tip is slowly retracted from the surface
a point contact junction gradually evolves from a N-S short to a high resistance tunnel junction. The scaled dynamic conductance
(dI/dV) of this point contact tunnel junction becomes almost identical to that of a conventional barrier type tunnel junction and
both show a linear dI/dV —V curve. The observation implies that at high resistance a point contact junction behaves in the same way as a barrier type
tunnel junction. We suggested that the almost linear tunneling conductance obtained in both the cases most likely arises due
to an intrinsic characteristic of the surface of the crystal comprising of a mosaic of superconducting regions of the order
of a few nanometers. We also conclude that the barrierless (N-S) point contact obtained by piercing the surface oxide layer
of the crystal shows Andreev reflection which we suggest as the origin of the zero bias anomaly often observed in point contact
junctions. 相似文献