排序方式: 共有102条查询结果,搜索用时 31 毫秒
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Thirupathi Ravula Nathaniel Z. Hardin Sudheer Kumar Ramadugu Sarah J. Cox Prof. Ayyalusamy Ramamoorthy 《Angewandte Chemie (International ed. in English)》2018,57(5):1342-1345
Polymer lipid nanodiscs are an invaluable system for structural and functional studies of membrane proteins in their near‐native environment. Despite the recent advances in the development and usage of polymer lipid nanodisc systems, lack of control over size and poor tolerance to pH and divalent metal ions are major limitations for further applications. A facile modification of a low‐molecular‐weight styrene maleic acid copolymer is demonstrated to form monodispersed lipid bilayer nanodiscs that show ultra‐stability towards divalent metal ion concentration over a pH range of 2.5 to 10. The macro‐nanodiscs (>20 nm diameter) show magnetic alignment properties that can be exploited for high‐resolution structural studies of membrane proteins and amyloid proteins using solid‐state NMR techniques. The new polymer, SMA‐QA, nanodisc is a robust membrane mimetic tool that offers significant advantages over currently reported nanodisc systems. 相似文献
43.
Sudhakar Kadari Hemasri Yerrabelly Jayaprakash Rao Yerrabelly Thirupathi Gogula Yadaiah Goud Gangadhar Thalari 《合成通讯》2018,48(14):1867-1875
An efficient and concise approach to the total synthesis of Paecilomycins E (1) and F (2), Cochliomycin C (4) and 6-epi-Cochliomycin C (3) is described. The synthesis involves novel route to the synthesis of Paecilomycin E and F and further conversion to Cochliomycin C and 6-epi-Cochliomycin C. Olefin metathesis and base promoted macro lactonization being the key reactions followed by chlorination to achieve target Cochliomycin C and 6-epi-Cochliomycin C. 相似文献
44.
J. S. Yadav P. Thirupathi Reddy S. Nanda A. Bhaskar Rao 《Tetrahedron: Asymmetry》2002,12(24):3381-3385
A simple and efficient stereoselective synthesis of (R)-denopamine and other naturally occurring hydroxy amides from optically active (R)-2-azido-1-arylethanols, is described for the first time via reduction of the corresponding -azidoarylketones with enzymes from Daucus Carota root, under mild and environmentally friendly conditions. The products are formed with high degrees of enantioselectivity. 相似文献
45.
Ponnaboina Thirupathi 《Tetrahedron》2010,66(45):8623-8628
Indium triflate-catalyzed allylation reactions of N-sulfonyl aldimines or N-alkoxyloxycarbonylamino p-tolylsulfone with allyltrimethylsilane have been successfully developed to produce protected homoallylic amines. 相似文献
46.
An efficient conversion of 4-bromo-3-yn-1-ols to γ-butyrolactones via AuCl(3)-catalyzed electrophilic cyclization (hydroxyl-assisted regioselective hydration) in wet toluene is described. Various secondary and tertiary alcohols including benzylic systems were found to be equally reactive with moderate to excellent yields obtained in all cases. 相似文献
47.
B. Sunil Kumar Y. Thirupathi Reddy P. Narsimha Reddy P. S. Kumar B. Rajitha 《Journal of heterocyclic chemistry》2006,43(2):477-479
Selectfluor? is used as an alternative catalyst to conventional catalysts for the synthesis of substituted coumarins via Pechmann condensation of phenols with β‐ketoesters under solvent‐free conditions at 120 °C. This method of synthesis is simple, cost‐effective, requires short reaction time, solvent‐free and gives good yields. 相似文献
48.
B. Sunil Kumar N. Srinivasulu R. H. Udupi B. Rajitha Y. Thirupathi Reddy P. Narsimha Reddy P. S. Kumar 《Russian Journal of Organic Chemistry》2006,42(12):1813-1815
A convenient procedure is reported for the synthesis of benzo[g]-and benzo[h]chromene derivatives via one-pot three-component condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate
and 1-or 2-naphthol in the presence of 10 mol % of titanium tetrachloride as catalyst. The reactions require no solvent; they
are characterized by simple experimental procedure and easy isolation and can be performed on enlarged scale.
Published in Russian in Zhurnal Organicheskoi Khimii, 2006, Vol. 42, No. 12, pp. 1824–1826.
The text was submitted by the authors in English. 相似文献
49.
Bending at the valence angle N–Cα–C′ (τ) is a known control feature for attenuating the stability of the rare intramolecular i→i hydrogen bonded pseudo five-membered ring C5 structures, the so called 2.05 helices, at Aib. The competitive 310-helical structures still predominate over the C5 structures at Aib for most values of τ. However at Aib∗, a mimic of Aib where the carbonyl O of Aib is replaced with an imidate N (in 5,6-dihydro-4H-1,3-oxazine = Oxa), in the peptidomimic Piv-Pro-Aib∗-Oxa (1), the C5i structure is persistent in both crystals and in solution. Here we show that the i→i hydrogen bond energy is a more determinant control for the relative stability of the C5 structure and estimate its value to be 18.5 ± 0.7 kJ/mol at Aib∗ in 1, through the computational isodesmic reaction approach, using two independent sets of theoretical isodesmic reactions. 相似文献
50.
Asha K. Dond Thirupathi Gudi 《Numerical Methods for Partial Differential Equations》2019,35(2):638-663
In this article, we develop patch‐wise local projection‐stabilized conforming and nonconforming finite element methods for the convection–diffusion–reaction problems. It is a composition of the standard Galerkin finite element method, the patch‐wise local projection stabilization, and weakly imposed Dirichlet boundary conditions on the discrete solution. In this paper, a priori error analysis is established with respect to a patch‐wise local projection norm for the conforming and the nonconforming finite element methods. The numerical experiments confirm the efficiency of the proposed stabilization technique and validate the theoretical convergence rates. 相似文献