The Composition of Ehrlich's Salvarsan: Resolution of a Century‐Old Debate

Abstract

Enthüllung geglückt: Die Hauptbestandteile des historisch wichtigen Pharmakons Salvarsan (Arsphenamin, Ehrlich 606) konnten nun mithilfe der ESI‐Massenspektrometrie identifiziert werden: Es handelt sich um Cyclopolyarsane [RAs]n (siehe Struktur; n=3–6, R=3‐Amino‐4‐hydroxyphenyl).

On the First Polyarsenic Organic Compound from Nature: Arsenicin A from the New Caledonian Marine Sponge Echinochalina bargibanti

“…In accordance, 13 C NMR spectra showed three methylene carbons, two of which are magnetically equivalent (Table 1). The optical inactivity of arsenicin A and the absence of a Cotton effect are in line with these elements of symmetry.…”

“…Structures 2 and 3 for arsenicin A, which better fit the observed 13 C NMR chemical shifts, are inconsistent with the tangled rearrangements that would have to be invoked to explain the MS fragmentations.…”

“…Structure 1 also explains the NMR spectroscopic homo and heterocorrelations. The high field 13 C NMR spectroscopic resonances are more problematic to rationalize in the absence of data for analogues; however, Table 1. NMR spectral data for arsenicin A (4).…”

Computational NMR Spectroscopy of Organoarsenicals and the Natural Polyarsenic Compound Arsenicin A

“…We have first computed the structure and NMR parameters of a series of organoarsenicals for which 1 H and 13 C NMR data are available or were thought to be relevant:…”

“…Nevertheless, some arsenicals have been used since more than a century for the treatment of certain infections such as syphilis, in the form of the drug Salvarsan, which is well known although poorly understood at the structural level. [1] In the antibiotics era, arsenicals have only played a specialized role, for instance, as antiparasitic agents in the treatment of sleeping sickness. [2] We are now witnessing a revival of arsenicals in the chemotherapy of cancer, [3] for example, the recent approval of As 2 O 3 (arsenic trioxide, ATO) for the treatment of promyelocytic leukaemia [4] and demonstration of its inhibitory activity towards thioredoxin reductase.…”