Maduramicin ls a polyether carboxylic ionophore produced by the prokaryotic Gram-positive bacterium Actinomadura yumaensis (formerly classified incorrectly as Nocardia X-148681)). It is a potent antibiotic with useful activity as a coccidiostat. Maduramicin was discovered and characterlzed independently by two diHbrcnt commercial Iaboratories:Hoffmann-La Roche Inc. designated the compound X-148...

A series of polyurethane elastomers based on an aliphatic diisocyanate and a polyether macroglycol was polymerized with various cross-link densities and OH/NCO ratios. Stoichiometries yielding between 8,600 and 12,900 gm/mole/crosslink and an OH/NCO ratio of 1.1 resulted in polymers with the low modulus, yet high strength and elongation necessary for maxillofacial applications.

A new type of materials, the backbone-thermoresponsive hyperbranched polyether, was successfully synthesized by proton-transfer polymerization of 1,4-butanediol diglycidyl ether and various triols, and the lower critical solution temperature (LCST) values can be readily adjusted from 19.0 to 40.3 degrees C by changing the hydrophilic/hydrophobic balance of BDE and triols.

Noboritomycins A and B, two new polycyclic ionophoric polyethers were isolated from a strain of Streptomyces noboritoensis. The crystal structure and absolute configuration of noboritomycin A were established by X-ray analysis of its silver salt C43/63O14Ag. Noboritomycin A is the first metabolic polyether possessing two carboxylic acid functions on the carbon backbone (C-31), namely a free aci...

Novel polyether antibiotics X-14873A, X-14873G, and X-14873H are produced by the fermentation of Streptomyces sp. X-14873 (ATCC 31679). This report presents taxonomic studies and fermentation conditions for the antibiotic producing culture. The antibiotics are mainly active against Gram-positive bacteria. The ionophore properties of X-14873A are also characterized.

Triptycene-derived macrotricyclic polyether containing an anthracene unit is a powerful host for 1,2-bis(pyridium)ethane, diquat and 2,7-diazapyrenium salt with association constants of the 1 : 1 complexes at >10(5) M(-1). Crystal structures showed that π-π stacking interactions between the host and the guests play an important role in the formation of the stable complexes.

A large covalent cage incorporating two porphyrins attached by four long and flexible polyether chains each bearing two 3-pyridyl ligands was synthesized from a DABCO-templated olefin metathesis reaction. The X-ray structure of the cage with the DABCO coordinated inside the cavity to the two zinc(II) porphyrins reveals a highly symmetric structure.

Polyalcohol is an environmentally friendly anti-collapse lubricant commonly used in water-based drilling fluids. It generally composed of the single polyether or polyol, but its lubricity and inhibition can’t satisfy application current fluid systems well. Consequently, laboratory has carried out research on compound polyalcohol. The samples are mixed with lauryl polyether, nonylphenol Tween 80...

Good footwear should be comfortable, long-lasting and fit for purpose, polyurethanes allow designers to meet all of these objectives. Polyurethanes are used in the industry make insoles shoe soles.There two types PU soles a polyether polyester based sole. Polyether have high resistance against hydrolysis low oil while resistance. In this work thermal mechanical properties elastomers with polols...

BACKGROUND The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition ha...