Anthracene Bisureas as Powerful and Accessible Anion Carriers

Abstract

Synthetic anion carriers (anionophores) have potential as biomedical research tools and as treatments for conditions arising from defective natural transport systems (notably cystic fibrosis). Highly active anionophores that are readily accessible and easily deliverable are especially valuable. Previous work has resulted in steroid and trans‐decalin based anionophores with exceptional activity for chloride/nitrate exchange in vesicles, but poor accessibility and deliverability. This work shows that anthracene 1,8‐bisureas can fulfil all three criteria. In particular, a bis‐nitrophenyl derivative is prepared in two steps from commercial starting materials, yet shows comparable transport activity to the best currently known. Moreover, unlike earlier highly active systems, it does not need to be preincorporated in test vesicles but can be introduced subsequent to vesicle formation. This transporter also shows the ability to transfer between vesicles, and is therefore uniquely effective for anion transport at low transporter loadings. The results suggest that anthracene bisureas are promising candidates for application in biological research and medicine.

Influence of the Insertion Method of Aryl‐Extended Calix[4]pyrroles into Liposomal Membranes on Their Properties as Anion Carriers

“…It is relevant to note, that using lucigenin assays for halide transport, Davis and co‐workers noticed abrupt quenching of the dye's fluorescence in the time‐course curves following the addition of high lipophilic anthracene bis‐urea transporters even at low concentrations. Subsequently, the fluorescence intensity reached a plateau at high values . The authors attributed this behaviour to a non‐homogeneous distribution of the carriers into the membranes and/or to poor insertion when added as external solutions (post‐insertion) …”

“…We observed the increase of the chloride transport mediation in response to higher carrier's loadings (control, 0.03 % and 0.1 % 2 /POPC molar ratio, Figure S15). Nevertheless, it is worth noting that the transport activity shown by carrier 2 using the lucigenin assay is low when compared to that of other transporters evaluated using this strategy …”

Chemical Syntheses and Chemical Biology of Carboxyl Polyether Ionophores: Recent Highlights

“…[2,85] Tr aditionally these features have been studied through in vitro assays where an aqueous solution of an ionophore and am etal ion (aqueous ion source) is separated from ap ure water phase (ion-receiving phase) by abulk organic phase that represents am odel membrane (Figure 2a). [86] We suggest that by exchanging the ion sensor,t his or closely related assays could be used to visualize metal ion transport into vesicles by fluorescence microscopy in real time (Figure 2b). [86] We suggest that by exchanging the ion sensor,t his or closely related assays could be used to visualize metal ion transport into vesicles by fluorescence microscopy in real time (Figure 2b).…”

Chemische Synthesen und chemische Biologie von Carboxylpolyether‐Ionophoren: Aktuelle Entwicklungen

“…[2,85] Zur Messung dieser Eigenschaften wurden klassischerweise In-vitro-Assays eingesetzt, bei denen die wässrige Lçsung eines Ionophors und eines Metall-Ions (wässrige Ionenquelle) von der reinen Wasserphase (ionenaufnehmende Phase) durch eine organische Phase,d ie eine Modellmembran repräsentiert, separiert sind (Abbildung 2a). [86] Wirs chlagen vor,d ass durch den Austausch des Ionensensors dieser oder eng verwandte Assays eingesetzt werden kçnnten, um den Metallionentransport in Vesikel durch Fluoreszenzmikroskopie in Echtzeit zu beobachten (Abbildung 2b). [86] Wirs chlagen vor,d ass durch den Austausch des Ionensensors dieser oder eng verwandte Assays eingesetzt werden kçnnten, um den Metallionentransport in Vesikel durch Fluoreszenzmikroskopie in Echtzeit zu beobachten (Abbildung 2b).…”