HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY OF CARDIAC STEROIDS

High performance liquid chromatography-tandem mass spectrometry (LS/MSn) utilizing an ion trap mass spectrometer has been used for the analyses of representative cardiac steroids. In the case of bufotoxin having a polar residue (suberoylarginine), the positive-electrospray ionization (ESI) was 50 times more sensitive than the atmospheric pressure chemical ionization (APCI) and provided information concerning the molecular weight as well as the structures of both aglycone and suberoylarginine. The corresponding bufogenin showed 2 times better sensitivity in the positive-APCI than ESI. The mass spectrum of digoxin with the positive-APCI showed fragment ions not only derived from aglycone but also formed by losses of sugars. The cleavage of the dioxane ring has been observed on the cardiac glycoside having an unusual sugar linkage. Fast atom bombardment mass spectra of these compounds were examined and compared with the data obtained from LC/MSn.

[1]  B. Ludes,et al.  High-performance liquid chromatography-ionspray mass spectrometry for the specific determination of digoxin and some related cardiac glycosides in human plasma. , 1997, Journal of chromatography. B, Biomedical sciences and applications.

[2]  F. Abe,et al.  Evaluation of positive and negative ion fast atom bombardment mass spectrometry for structural investigations on cardenolide-type cardiac glycosides. , 1986, Biomedical & environmental mass spectrometry.

[3]  K. Tomer,et al.  Fast atom bombardment and tandem mass spectrometry for structure determination of steroid and flavonoid glycosides. , 1986, Analytical Biochemistry.

[4]  T. Nambara,et al.  Structure-activity relationship of bufotoxins and related compounds for the inhibition of Na+, K+ -adenosine triphosphatase. , 1985, Journal of pharmacobio-dynamics.

[5]  S. M. Kupchan,et al.  Isolation and Characterization of Cardiotonic Steroids from the Bulb of Urginea altissima BAKER , 1979 .

[6]  T. Nambara,et al.  Isolation and characterization of cardiotonic steroid conjugates from the skin of Bufo marinus (L.) Schneider. , 1979, Chemical & pharmaceutical bulletin.

[7]  T. Nambara,et al.  Syntheses of Bufotoxin Analogs , 1973 .

[8]  H. Wieland,et al.  Über den Giftstoff der Kröte , 1922 .

[9]  J. Josephs.  Detection and characterization of fumonisin mycotoxins by liquid chromatography/electrospray ionization using ion trap and triple quadrupole mass spectrometry. , 1996, Rapid communications in mass spectrometry : RCM.

[10]  T. Nambara,et al.  Structures of elaeodendrosides B, C, F, G, K and L, a series of cardiac glycosides isolated from Elaeodendron glaucum , 1985 .