Use of a dihydrogen osmium complex as a versatile 1H NMR recognition probe.
A new recognition probe for biomolecules, [en2Os(eta 2-H2)]2+ (1; en, ethylenediamine), is reported. In aqueous solution, 1 binds readily to a variety of biomolecules, including nucleotides, RNA, amino acids, peptides, and phospholipids. In each case, binding leads to a characteristic proton nuclear magnetic resonance (1H NMR) for the dihydrogen that appears in a spectral window in the range delta = 0 to -20 parts per million, and as well to characteristic values of the coupling JHD and of the relaxation time T1. Small structural differences in molecules such as DGMP (2'-deoxyguanosine 5'-monophosphate) and IMP (inosine 5'-monophosphate) or Asp and Glu can readily be distinguished, such as when 1 binds to the N-7 position of the nucleobase of DGMP or IMP and when 1 binds to the carboxylate of Asp or Glu. Upon one-electron oxidation of the metal center, diamagnetic 1 is converted to a paramagnetic probe.
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Department of Chemistry, Stanford University, CA 94305.
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D000596:Amino Acids / Q000737:chemistry*; D001224:Aspartic Acid; D003854:Deoxyribonucleotides / Q000737:chemistry; D005029:Ethylenediamines; D005971:Glutamates; D018698:Glutamic Acid; D006859:Hydrogen; D007202:Indicators and Reagents; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009992:Osmium; D012265:Ribonucleotides / Q000737:chemistry*
D000596:Amino Acids; D003854:Deoxyribonucleotides; D005029:Ethylenediamines; D005971:Glutamates; D007202:Indicators and Reagents; D008024:Ligands; D012265:Ribonucleotides; D009992:Osmium; D001224:Aspartic Acid; D018698:Glutamic Acid; C074104:aquabis(ethylenediamine)dihydrogenosmium; D006859:Hydrogen