"(2S,3R)-2,3-Dihydroxy-2-(1-methylethyl)butanoic Acid [(1R,7aR)-2,3,5,7a-Tetrahydro-1-hydroxy-4-oxido-1H-pyrrolizin-7-yl]methyl Ester-D7; [1R-[1a,7(2S*,3R*),7aß]]-2,3-Dihydroxy-2-(1-methylethyl)butanoic Acid (2,3,5,7a-Tetrahydro-1-hydroxy-1H-pyrrolizin-7-y",Intermedine NA Stable Isotopes