Structure elucidation of indole–indoline type alkaloids: A retrospective account from the point of view of current NMR and MS technology

► The challenges of determining the structure of bisindoles. ► Historical roles of NMR and mass spectrometry in bisindole structure elucidation. ► The capabilities of modern NMR and MS in bisindole structure elucidation. ► Demonstrative examples are discussed for vinblastine and vincristine analogues. In this review our aim is to look back on how the structure elucidation of bisindoles, especially with focus placed on vinblastine and vincristine analogues, has evolved alongside with the development of MS and NMR over the last 60 years from the perspective of our present-day use of state-of-the-art MS and NMR instrumentation and on the basis of our own accumulated views and experience in the field.