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Abstract A facile procedure is presented for the synthesis of (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2- propen-1-one (6). Galactosylisomaltol (1) was condensed with isovanillin (2) under strong alkaline conditions at 25 [ddot]C to form (E)-1-(3′-O-β-D-galactopyranosyloxy-2′-furanyl)-3-(3″- hydroxy-4″-methoxyphenyl)-2-propen-1-one (4). (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2-propen-1-one (6) was obtained by acid hydrolysis of 4 in a 53.9% yield. This hetero-cyclic 2-propen-1-one was characterized on the basis of spectral data (IR and 1H NMR), physicochemical properties, and conversion to a mono-O-acetyl derivative. 相似文献
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Harvey SD Mong GM Ozanich RM McLean JS Goodwin SM Valentine NB Fredrickson JK 《Analytical and bioanalytical chemistry》2006,386(2):211-219
A novel, affinity-augmented, bacterial spore-imprinted, bead material was synthesized, based on a procedure developed for
vegetative bacteria. The imprinted beads were intended as a front-end spore capture/concentration stage of an integrated biological
detection system. Our approach involved embedding bead surfaces with Bacillus thuringiensis kurstaki (Bt) spores (as a surrogate for Bacillus anthracis) during synthesis. Subsequent steps involved lithographic deactivation using a perfluoroether; spore removal to create imprint
sites; and coating imprints with the lectin, concanavalin A, to provide general affinity. The synthesis of the intended material
with the desired imprints was verified by scanning electron and confocal laser-scanning microscopy. The material was evaluated
using spore-binding assays with either Bt or Bacillus subtilis (Bs) spores. The binding assays indicated strong spore-binding capability and a robust imprinting effect that accounted for 25%
additional binding over non-imprinted controls. The binding assay results also indicated that further refinement of the surface
deactivation procedure would enhance the performance of the imprinted substrate. 相似文献
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Kieran W. P. Orr Sean M. Collins Emily M. Reynolds Frank Nightingale Hanna L. B. Bostrm Simon J. Cassidy Daniel M. Dawson Sharon E. Ashbrook Oxana V. Magdysyuk Paul A. Midgley Andrew L. Goodwin Hamish H.-M. Yeung 《Chemical science》2021,12(12):4494
Control over the spatial distribution of components in metal–organic frameworks has potential to unlock improved performance and new behaviour in separations, sensing and catalysis. We report an unprecedented single-step synthesis of multi-component metal–organic framework (MOF) nanoparticles based on the canonical ZIF-8 (Zn) system and its Cd analogue, which form with a core–shell structure whose internal interface can be systematically tuned. We use scanning transmission electron microscopy, X-ray energy dispersive spectroscopy and a new composition gradient model to fit high-resolution X-ray diffraction data to show how core–shell composition and interface characteristics are intricately controlled by synthesis temperature and reaction composition. Particle formation is investigated by in situ X-ray diffraction, which reveals that the spatial distribution of components evolves with time and is determined by the interplay of phase stability, crystallisation kinetics and diffusion. This work opens up new possibilities for the control and characterisation of functionality, component distribution and interfaces in MOF-based materials.Core–shell metal–organic framework nanoparticles have been synthesised in which the internal interface and distribution of components is found to be highly tunable using simple variations in reaction conditions. 相似文献
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The first enantioselective organocatalytic Mukaiyama-Michael reaction using alpha,beta-unsaturated aldehydes has been accomplished. The use of iminium catalysis has provided a new strategy for the enantioselective addition of 2-silyloxy furans to unsaturated aldehydes to generate a variety of butenolide systems, an important chiral synthon found among many natural isolates. The (2S,5S)-5-benzyl-2-tert-butyl-imidazolidinone amine catalyst has been found to mediate the conjugate addition of a wide variety of substituted and unsubstituted silyloxy furans to unsaturated aldehydes. A diverse range of aldehyde substrates can be accommodated in this new organocatalytic transformation. Application of this new asymmetric technology to the enantioselective total synthesis of spiculisporic acid and the corresponding 5-epi-spiculisporic acid analogue is also discussed. 相似文献
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Abstract— The quantitative changes in the levels of RNA and DNA in shoots treated with red and/or far-red light are presented.
The results indicate that red light, but not far-red light, stimulated cell division. The changes in RNA are discussed in relation to the nature of the light treatment. 相似文献
The results indicate that red light, but not far-red light, stimulated cell division. The changes in RNA are discussed in relation to the nature of the light treatment. 相似文献