Mass spectrometry in the development of drugs from traditional medicines

The mass spectrometer ionizes molecules to separate and weigh the resulting molecular ions and their dissociation products. These product masses indicate directly the sequence of constituents of the original molecule, such as amino acids in proteins or bases in nucleotides. Because single ions can be detected, even subfemtomole sensitivities are possible. In tandem mass spectrometry (MS/MS), molecular ions from a mixture can be separated to isolate ions of a specific component, whose further dissociation can then give structural information on that component. Electrospray ionization and other recently developed methods make possible the ionization of biomolecules even larger than 100 kDa. The Fourier-transfer mass spectrometer has unusual capabilities for measuring ions over a 100 kDa mass range simultaneously at unit resolution for MS/MS applications utilizing subfemtomole sample quantities.