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1.
Stability regions of -methods for the linear delay differential test equations
0, \hfill \\ y(t) = \varphi (t),t \in [ - \tau ,0], \hfill \\ \end{gathered}$$
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Three new diterpenoids with a substituted α-cyclogeraniol skeleton have been isolated from the umbelliferae (Vahl) Lange, for which the names of magydar-2,13-dien-11,17-diol, , magydar-2,10 (20), 13-trien-17-ol, , and magydar-2,10(20), 13-trien-17-yl acetate, , are proposed. The structures of these substances have been deduced from spectroscopic and chemical data. 相似文献
3.
J.-T.De Pascual E. Caballero C. Caballero M. Medarde A.F. Barrero M. Grande 《Tetrahedron》1982,38(12):1837-1842
Trixagol 1 and fourteen derivatives with the skeleton of γ-cyclogeranil geraniol were isolated from Bellardia trixago, the structures were determined by spectroscopic methods and confirmed by partial synthesis. Furthermore. 3,4-dihydro-γ-ionone, α-ambrinol, β-sitosterol and three flavonoids 5-O-demethyl tangeretin, 5-hydroxy auranetin and 3′-methoxy calycopterin were also isolated. 相似文献
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Julien Ramier Estelle Renard Daniel Grande 《Journal of polymer science. Part A, Polymer chemistry》2012,50(7):1445-1455
Microwave (MW)‐assisted ring‐opening polymerization (ROP) provides a rapid and straightforward method for engineering a wide array of well‐defined poly(3‐hydroxyalkanoate)‐b‐poly(D,L ‐lactide) (PHA‐b‐PLA) diblock copolymers. On MW irradiation, the bulk ROP of D,L ‐lactide (LA) could be efficiently triggered by a series of monohydroxylated PHA‐based macroinitiators previously produced via acid‐catalyzed methanolysis of corresponding native PHAs, thus affording diblock copolyesters with tunable compositions. The dependence of LA polymerization on temperature, macroinitiator structure, irradiation time, and [LA]0/[PHA]0 molar ratio was carefully investigated. It turned out that initiator efficiency values close to 1 associated with conversions ranging from 50 to 85% were obtained only after 5 min at 115 °C. A kinetic investigation of the MW‐assisted ROP of LA gave evidence of its “living”/controlled character under the experimental conditions selected. Structural analyses and thermal properties of biodegradable diblock copolyesters were also performed. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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Francesca Sisto Simone Carradori Paolo Guglielmi Mattia Spano Daniela Secci Arianna Granese Anatoly P. Sobolev Rossella Grande Cristina Campestre Maria Carmela Di Marcantonio Gabriella Mincione 《Molecules (Basel, Switzerland)》2021,26(7)
Following a similar approach on carvacrol-based derivatives, we investigated the synthesis and the microbiological screening against eight strains of H. pylori, and the cytotoxic activity against human gastric adenocarcinoma (AGS) cells of a new series of ether compounds based on the structure of thymol. Structural analysis comprehended elemental analysis and 1H/13C/19F NMR spectra. The analysis of structure–activity relationships within this molecular library of 38 structurally-related compounds reported that some chemical modifications of the OH group of thymol led to broad-spectrum growth inhibition on all isolates. Preferred substitutions were benzyl groups compared to alkyl chains, and the specific presence of functional groups at para position of the benzyl moiety such as 4-CN and 4-Ph endowed the most anti-H. pylori activity toward all the strains with minimum inhibitory concentration (MIC) values up to 4 µg/mL. Poly-substitution on the benzyl ring was not essential. Moreover, several compounds characterized by the lowest minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) values against H. pylori were also tested in order to verify a cytotoxic effect against AGS cells with respect to 5-fluorouracil and carvacrol. Three derivatives can be considered as new lead compounds alternative to current therapy to manage H. pylori infection, preventing the occurrence of severe gastric diseases. The present work confirms the possibility to use natural compounds as templates for the medicinal semi-synthesis. 相似文献
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