130792-91-5

Upstream product

• 96020-49-4 C₁₄₂H₂₁₈N₂O₂₆P₂ 
• 230966-96-8 C₁₄₄H₂₂₀N₂O₂₅P₂ 

Relevant academic research and scientific papers

TOTAL SYNTHESIS OF ESCHERICHIA COLI LIPID A

The first total synthesis of E. coli lipid A (1) is described.The synthetic compound was identical with a natural specimen and exhibited the full endotoxic activity.It was thus conclusively proved by this chemical synthesis that lipid A is the active prin

Nuclear magnetic resonance of lipid A - The influence of solvents on spin relaxation and spectral quality

Nuclear magnetic resonance (NMR) spectroscopy of lipid A is limited by rapid transversal relaxation and subsequent line broadening caused by the tendency of these glycolipids to form aggregates in all solvents. To examine the influence of solvents on NMR spectra, hexa-acyl lipid A from Escherichia coli F515 was investigated. Line widths at half height, longitudinal relaxation times, and transversal relaxation times were measured in different solvents, lipid A concentrations, and temperatures. Chloroform-d, dioxane-d8, and pyridine-d5 each mixed with 25% methanol-d4 as well as sole DMSO-d6 and 0.1M triethylamine-d15 (TEA-d 15) in D2O caused good spectral resolutions and allowed structure analysis. ROESY and HMBC spectra gave an insight into the influence of transversal relaxation times on spectral quality in two-dimensional spectra. Solvent depending differences of interglycosidic NOEs indicated dissimilarities of the conformations in the interglycosidic linkage and allowed conclusions about the lipid A solution state.

New efficient route for synthesis of lipid A by using affinity separation

New efficient synthesis of lipid A, an immunostimulating glycoconjugate of bacteria, was achieved for the construction of lipid A library by using synthesis based on affinity separation (SAS), where the compounds possessing a barbituric acid (BA)-tag are selectively and rapidly purified by interaction with an artificial receptor for BA. Glycosylation of a glycosyl acceptor possessing the BA-tag with a 4' -phosphorylated N-Troc glucosaminyl trichloroacetimidate gave the disaccharide 4' -phosphate, which was purified by the affinity separation. Successive rémoval of protective groups and introduction of acyl groups were then effected and the synthetic intermediate at each step was purified by the affinity separation. Cleavage of the tag and subsequent deprotection afforded Escherichia coli lipid A. SAS enabled the rapid preparation of lipid A, therefore, proved to be a promising method for synthesis of other complex glycoconjugates.

A divergent synthesis of lipid A and its chemically stable unnatural analogues

Lipid A and its two chemically stable analogues, wherein the glycosidic phosphoryl groups in lipid A is replaced with 2-(phosphonooxy)ethyl or carboxymethyl groups, have been synthesized by an improved and divergent route via a common allyl glycoside intermediate in which the 4-hydroxy group was protected as a benzyl ether. The total yields were more than 20% for 11 or 12 steps starting from allyl 4,6-O-benzylidene-2-deoxy-2- (trichloroethoxycarbonylamino)-D-glucopyranoside. These synthetic chemically stable analogues induce interleukin-6 and tumor necrosis factor a in human peripheral whole blood cells with potencies comparable to those by natural- type synthetic lipid A. The Limulus activities of both analogues were found to be even stronger than the activity of the natural-type one.

Total Synthesis of Escherichia coli Lipid A, the Endotoxically Active Principle of Cell-Surface Lipopolysaccharide

Chemical synthesis are described of polyacylated β(1->6) glucosamine disaccharide 1,4'-bis(phosphate), which corresponds to the proposed structure of E. coli lipid A, and of its dephospho derivatives.The synthetic bisphosphate proved to be identical with