Comparison of the solubility in supercritical fluids of the polycyclic ether antibiotics: Lasalocid, monensin, narasin, and salinomycin

✍ Scribed by Robert J. Maxwell; James W. Hampson; Miriam L. Cygnarowicz-Provost

• Book ID: 103929703
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 595 KB
• Volume: 5
• Category: Article
• ISSN: 0896-8446
• DOI: 10.1016/0896-8446(92)90038-l

✦ Synopsis

Solubility measurements for the polycyclic ethers (lasalocid, monensin, narasin, and salinomycin) were determined as sodium salts in pure CO2 and with CO2 modified with methanol and water at temperatures of 60-80 "C and 140-400 bar using an SFE instrument with a recirculating-loop fluid system. Wide variations in solubility within this antibiotic class were observed. Narasin and salinomycin were found to have almost identical solubilities in supercritical CO2, 1.35 x 10-X mol/L (80 "C and 390 bar) while monensin was much lower in solubility, 2.34 x 1OA mol/L (80 "C and 390 bar). Lasalocid showed no measurable solubility under similar experimental conditions. Similar differences were observed when solubilities were determined in CO2 modified with methanol and water. These variations in measured solubilities were attributed, in part, to dissimilarities among the conformations of the polycyclic ether/cation complexes in solution.