QFI qfi ({4-[(2S,3R)-2-({[(3R,3AS,6AR)-HEXAHYDROFURO[2,3-B]FURAN-3-YLOXY]CARBONYL}AMINO)-3-HYDROXY-4-{ISOBUTYL[(4-METHOXYPHENYL)SULFONYL]AMINO}BUTYL]PHENOXY}METHYL)PHOSPHONIC ACID QFI