Towards aqueous chiral heptadentate lanthanide complexes as selective shift and relaxation agents for MRS
作者:Rachel S. Dickins、Alessandra Badari
DOI:10.1039/b706801h
日期:——
heptadentate, lanthanidecomplexes have been synthesized and their potential to act as shift and relaxation agents in MRS (for lactate, in particular) has been assessed through (1)H NMR analysis. The binding affinity and enantiopurity of the complexes have been modulated by systematic variation of the lanthanide ion and ligand structure, in particular the peripheral electrostatic charge of the complex (cationic
Synthesis and organogelating behaviour of amino acid-functionalised triphenylenes
作者:Jonathan E. Meegan、Xiaofei Yang、Ratana Rungsirisakun、Sebastian C. Cosgrove、Richard J. Bushby、Amin Sadeghpour、Michael Rappolt、Rik Brydson、Richard J. Ansell
DOI:10.1039/c7sm00676d
日期:——
been prepared with glycine, L-alanine, L-phenylalanine and L-tryptophan ethyl ester side-chains. The glycine derivative is a good gelator of chloroform, the alanine derivative gels ethanol and toluene, and the phenylalaninederivative gels benzene and toluene. The tryptophan derivative does not gel any of the solvents tested, most probably due to its more bulky structure, but forms microspheres by evaporation-induced
Comparative study of the constitution and chiroptical properties of emissive terbium and europium complexes with a common tetraazatriphenylene sensitiser; the nature of the sensitiser determines quenching sensitivity and cellular uptake
作者:Elizabeth J. New、David Parker、Robert D. Peacock
DOI:10.1039/b816173a
日期:——
Six pairs of Eu(III) and Tb(III) complexes of macrocyclic ligands, incorporating a common tetraazatriphenylene sensitiser, have been examined in terms of their solution structure, sensitivity to excited state quenching, protein affinity, cell toxicity and preliminary cell localisation profiles. A complex with three (S)-phenylalanine-derived ligating groups possesses distinctive 1H NMR, Eu emission and circularly polarised emission properties, consistent with a unique Λ-configuration in the 9-coordinate complex, where an amide carbonyl group occupies the capping position of the coordination polyhedron. Each complex possesses similar sensitivity to quenching by ascorbate, urate and iodide, has similar toxicity behaviour and shows a common intracellular localisation profile that is consistent with compartmentalisation in lysosomes or late endosomes. Such behaviour accords with the hypothesis that it is the nature of the sensitising moiety that determines each of these properties.
Chemodivergent Staudinger Reactions of Secondary Phosphine Oxides and Application to the Total Synthesis of LL–D05139β Potassium Salt
作者:Wenjun Luo、Fang Xu、Zhenguo Wang、Jiyan Pang、Zixu Wang、Zhixiu Sun、Aiyun Peng、Xiaohui Cao、Le Li
DOI:10.1002/anie.202310118
日期:2023.10.9
Unprecedented chemodivergent Staudinger reactions of secondary phosphine oxides (SPO) have been developed. Reagent-controlled 1- or 2-nitrogen atom exclusions from azides have been achieved. Conversion of a chiral SPO to a phosphinic amide was stereoretentive, and the potassium salt of natural product LL-D05139β was synthesized for the first time.
Efficient Coupling of Amino Acid Derivatives to Rigid Organic Scaffolds: Model Syntheses for De Novo Proteins.
作者:Bruce C. Gibb、Adam R. Mezo、Ashley S. Causton、Janet R. Fraser、Frank C.S. Tsai、John C. Sherman
DOI:10.1016/0040-4020(95)00485-q
日期:1995.8
We describe the coupling of amino acid derivatives to four different rigid organic macrocycles. The couplings were achieved in high yields, which augurs well for the coupling of polypeptides to the rigid macrocycles to create a new family of de novo proteins. We discuss the structure of the model compounds based on the hydrogen bonding patterns that are evident from their NMR and IR spectra.