Supramolecular Complexes Formed by the Self-assembly of Hydrophobic Bis(Zn²⁺-cyclen) Complexes, Copper, and Di- or Triimide Units for the Hydrolysis of Phosphate Mono- and Diesters in Two-Phase Solvent Systems (Cyclen=1,4,7,10-Tetraazacyclododecane)

Abstract

2− into the aqueous layer. The findings indicate that 9 and 10 exhibit phosphatase activity in the two-phase solvent system, although catalytic turnover was not observed. Furthermore, the hydrolysis of BNP catalyzed by the hydrophobic 2 : 2 : 2 supermolecules in the two-phase solvent system is described.

Catalytic Hydrolysis of Phosphate Monoester by Supramolecular Complexes Formed by the Self-Assembly of a Hydrophobic Bis(Zn2+-cyclen) Complex, Copper, and Barbital Units That Are Functionalized with Amino Acids in a Two-Phase Solvent System

“…The results for the hydrolysis of MNP by the supramolecular phosphatases at [MNP] = 100, 200, 500, 800, and 1000 μ M (in the total solution) were analyzed based on Michaelis–Menten kinetics, as described in our previous reports (the hydrolysis of MNP by 16d , 16h , and 16i were carried out at [MNP] = 100, 200, 300, 400, and 500 μ M (in the total solution)) [19,24,53,54]. Based on the Lineweaver–Burk plots shown in Figure 10, V max (the maximum velocity for the formation of NP from MNP promoted by 9 , 16 , and 17 , μ M min −1 ), K m (Michaelis constant, μ M), and k (the first-order rate constant defined by Equation (1), min −1 ) [57] values were determined and summarized in Table 2.…”

“…The yields of the hydrolysis product from MNP in the presence of the supramolecular complexes were calculated based on the increase in the absorption of the released 4-nitrophenol (NP) at 400 nm ([NP produced in the presence of the supramolecular complex]–[NP produced in the absence of the supramolecular complex]) ( ε 400 value of NP is 1.35 × 10 4 M −1 ·cm −1 at pH 7.4) [17] in aqueous layer. The partition ratio of NP (79% in aqueous solution), which had been determined in the previous report [53], was used for the calculation of the yields in the CHCl 3 /H 2 O system.…”

“…We also reported on the formation of the hydrophobic supramolecular complexes 9a – c and the amphiphilic supramolecular complexes 10a – c (Scheme 1a) by the 2:2:2 assembly of a hydrophobic bis(Zn 2+ -cyclen) complex containing two long alkyl chains 2 (Zn 2 L 2 ) and a complex that contained one long alkyl chain 3 (Zn 2 L 3 ), respectively, with Bar 2− derivatives and Cu 2+ in a two-phase solvent system (CHCl 3 /H 2 O) [53,54]. As shown in Scheme 2, we expected that the hydrophobic or amphiphilic 2:2:2 complexes 9 or 10 would be formed mainly in the organic layer, and that product inhibition by HPO 4 2− could be avoided, since the hydrophilic HPO 4 2− would be released into the aqueous layer, thus permitting the Cu 2 ( μ -OH) 2 core to be regenerated.…”

“…The results showed that 9 and 10 accelerated the hydrolysis of MNP and one of most important findings was that the hydrolysis of MNP by 9 and 10 in the two-phase solvent system obeyed Michaelis–Menten kinetics, suggesting that these reaction systems consisting of a supramolecular complex in two-phase solvent system closely mimic the active sites of AP. However, catalytic activity was observed only in the case of 10 (the catalytic turnover numbers (CTN) were 3~4 [54]), but not in 9 [53]. In addition, the product inhibition of 9 and 10 by inorganic phosphate (HPO 4 2− ) was not competitive, although it is well known that HPO 4 2− inhibits natural AP in a competitive manner.…”

Theoretical Investigation of the Newly Designed Benzimidazole Based Metal Mediated DNA Base Couples with DFT Method

“…Today, development of biomolecular structures is generally based on supramolecules that include non-covalent interactions, such as hydrogen bonds, hydrophobic effects and metal coordination bonds [1] [2] [3] [4]. Without a F. Sevin et al doubt, the most basic structures in origins of the chemical evolution are the nucleic acids.…”