116058-79-8Relevant articles and documents
Syntheses of Macrocyclic Enzyme Models. Part 6. Preparation and Guest-Binding Behaviour of Octopus Cyclophanes
Murakami, Yukito,Kikuchi, Jun-ichi,Suzuki, Masashi,Matsuura, Takeo
, p. 1289 - 1300 (2007/10/02)
The following octopus cyclophanes constructed with a rigid macrocyclic skeleton and eight flexible hydrocarbon chains were prepared: N,N',N'',N'''-tetrakis(2-carbamoyl>ethyl)-3,10,21,28-tetraoxo-2,11,20,29-tetra-azaparacyclophane tetrachloride 2Lys2C14)4> and N,N',N'',N'''-tetrakispentan-5-yl>carbamoyl)ethyl>-3,10,21,28-tetraoxo-2,11,20,29-tetra-azaparacyclophane tetrabromide 2Lys(C5N+)2C14>4>.These host molecules provide cavities that are deep and hydrophobic enough to incorporate hydrophobic guests of various bulkiness through an induced-fit mechanism originating from the flexible character of the alkyl branhes.Both hydrophobic and electrostatic interactions come into effect in the host-guest complexation process, so that the molecular recognition is excercised by the preset hosts toward guests molecules.As regards the inclusion equilibrium between APC2Lys(C5N+)2C14>4 and pyrene, formation of both 1:2 and 1:1 (host:guest) complexes was remarkably favoured.The hydrophobic cage provided by the octopus cyclophane is highly apolar and acts to repress the molecular motion of guests; this was confirmed by fluorescene and fluorescence polarization spectroscopy, respectively.Both 2-azidobiphenyl and pyrene were simultaneously incorporated into the cyclophane cage as evidenced by kinetic analysis, and the pyrene-senzitized photolysis of the former species was enhanced under such conditions.The results imply that the octopus cyclophanes can be utilized as effective apoenzyme models for simulation of enzymatic functions.
