Crown Ether Functionalized Potassium‐Responsive Anionocages for Cascaded Guest Delivery

Abstract

In many critical biological processes, host–guest chemistry of protein receptors is regulated by effector molecules to realize cascaded delivery of messenger molecules between different targets. Mimicking these natural processes with artificial receptors remains a challenge. Herein, we report a cascaded guest delivery between two anionocages (anion‐coordination‐driven cages), in a reversible manner, wherein binding of K+ ions by a crown ether functionalized, heteroleptic A2L3 (A=anion, L=ligand) anionocage triggers the release and delivery of a TEA+ (tetraethylammonium) guest to another A2L3 anionocage that is a weaker and less K+‐sensitive receptor. Elimination of the K+ with [2,2,2]‐cryptand enables recapture of the TEA+ by the crown ether functionalized anionocage and thus realizes a reversed guest delivery. Moreover, integrative self‐sorting of anionocages is firstly reported, leading to heteroleptic cages with enhanced guest binding affinities.

Identification of Photocatalytic Alkaloids from Coptidis Rhizome by an Offline HPLC/CC/SCD Approach

“…Several approaches are being pursued to address this limitation: (i) Host–guest chemistry. Cucurbituril [ 27 ], porphyrins [ 28 ], crown ether [ 29 ], calixarenes [ 30 ], cyclodextrins [ 31 ], co-crystals [ 32 , 33 ], MOF [ 34 ], and the recently reported mechanically interlocked structures [ 35 ] have proven abilities to capture a broad range of different organic molecules. (ii) Hydrogen-bonded frameworks.…”

Self-sorting assembly of artificial building blocks

“…41 With the recognition of host and guest, self-sorting assemblies from multi-complex systems can be fabricated, and even functional materials are realizable. 42…”

“…41 With the recognition of host and guest, selfsorting assemblies from multi-complex systems can be fabricated, and even functional materials are realizable. 42 Typical host molecules, such as crown ethers, cyclodextrins, cucurbiturils, and calixarenes are suitable candidates for the construction of self-sorting systems. [43][44][45][46] Cucurbiturils (CB) as host molecules have been extensively explored due to their high binding constants and great suitability of guests including positively charged and neutral ones.…”

Recent Updates on Supramolecular‐Based Drug Delivery – Macrocycles and Supramolecular Gels

“…Other major macrocycles explored for drug delivery are crown ethers and porphyrins. Earlier reports [62] on crown ethers include crown ethers for inhibition of P‐glycoprotein‐mediated efflux of anti‐tumor drug, [62a] crown ether functionalized dendrons for dopamine delivery, [62b] 1,16‐hexadecanoyl‐bis‐(2‐aminomethyl)‐18‐crown‐6 for 5‐fluorouracil release, [62c] 18‐crown‐6 ether for cancer therapy, [62d] iron oxide core and mesoporous silica shell with crown ether periphery, [62e] 12‐crown‐4, 15‐crown‐5, and 18‐crown‐6 for ocular delivery, [62f] 16 adamantane‐substituted monoaza/diaza‐18‐crown‐6 ether, [62g] and crown ether functionalized heteroleptic anionocages [62h] . A few reviews specific to crown ethers in drug delivery are available [63]…”