IDENTIFICATION OF ADENINE NUCLEOTIDE-CONTAINING METABOLITES OF BISPHOSPHONATE DRUGS USING ION-PAIR LIQUID CHROMATOGRAPHY-ELECTROSPRAY MASS-SPECTROMETRY

Bisphosphonates are synthetic pyrophosphate analogues, which are used as therapeutic drugs for the treatment of metabolic bone disorders. So me of these bisphosphonates can be metabolised in cells into non-hydro lysable nucleotide analogues. In this paper, we describe an ion-pairin g high-performance liquid chromatography method that is compatible wit h negative ion electrospray mass spectrometry for the separation of th ese metabolites. Tandem mass spectrometry and collision-induced dissoc iation (CID) were used for identification of the metabolites. The CID mass spectra of bisphosphonate-adenine nucleotide adducts are very inf ormative, because major fragment ions are formed by cleavage of the bi sphosphonate moiety from the conjugate. The method was used for detect ion of the nucleotide metabolites of clodronate, tiludronate and etidr onate in extracts from mammalian cells after treatment with bisphospho nates. (C) 1997 Elsevier Science B.V.