Telluroxides Exhibit Hydrolysis Capacity

Abstract

It has long been known that tellurium compounds are rather toxic to living organisms, and tellurium has not been found in natural biomacromolecules to date. The principles of telluride toxicity in biological processes are still controversial partly because of the lack of information on the biochemical features of tellurium. In this contribution, we report our finding for the first time that telluroxides exhibit hydrolysis capacity. For instance, 6,6'-telluroxy-bis(6-deoxy-beta-cyclodextrin) acts as a hydrolase mimic and shows a significant rate acceleration of 106,000 for the hydrolysis of 4,4'-dinitrodiphenyl carbonate.

Ester catalytic hydrolysis by a tridentate N,N′,N″-copper bridged cyclodextrin dimer

“…Monitoring the formation of 4-nitrophenolate by UV at 400 nm (ε obs =8700 M −1 cm −1 ) [43], the initial hydrolysis rates of BNPC (50 μM) and NA (400 μM) in the presence of the catalysts were calculated ( Table 1). The measured initial rate of spontaneous cleavage of BNPC (50 μM) was very slow (υ control =2.45×10 −10 M s −1 ), which was consistent with the reported value [44]. Almost no rate enhancement in the hydrolysis was observed when only the copper cation was added to the solution of BNPC or NA.…”

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2007–2008

“…As antimalarials (Crandall, et al, 2007) 6,6'-telluroxy-bis(6-deoxy-β -cyclodextrin) and related compounds MALDI Demonstration that telloroxides exhibit hydrolysis capacity (Dong, et al, 2007) Thiol-modified β-CD TOF Construction of gold nanoparticles for fingerprint detection (Becue, et al, 2007) Cyclodextrin plus γ-valerolactone TOF Ring-opening polymerization of cyclic esters by cyclodextrins ) Polymers Amphiphilic block copolymers TOF Self-association of bis-(α,β-Dglucopyranosyl)-polyisobutylene (Orosz, et al, 2007) Biotin α-end-functionalized glycopolymers TOF (CHCA) RAFT copolymerization of acrylamide derivs. of Gal with N-acryloylmorpholine in the presence of a biotin CTA (Gody, et al, 2008) Branched supramolecular polymers from CDs TOF From 3-cinnamamide-α-CD and 3-Ncinnamamidehexane-carbonyl-N ε -cinnamamide-lysinamide-α-CD (Miyawaki, et al, 2008a) Cellulose acetate modified with caprolactone R-TOF Various reaction conditions.…”

Construction of a Hyperbranched Supramolecular Polymer as a Bifunctional Antioxidative Enzyme Model

“…Synthesis of 6-Te-diCD [32] 6-Te-diCD was synthesized according to the procedure previously used in our group. The obtained residue was purified on a column of Sephadex G-25 with distilled H 2 O as the eluent.…”

“…[32] Now, in order to construct a HBSP enzyme model, the dimer of 6-Te-diCD was used as a 'supramolecular linker' to form a HBSP through host/guest interaction. The GPx-like activity of the catalyst was studied following a modified method reported by Hilvert et al [37] using 4-nitrobenzenethiol as a thiol substrate.…”

“…Considering that 6-Te-di-CD has a specific binding cavity for recognizing the substrate ArSH, it is surprising that the model catalyst in which the CD cavities were replaced by adamantyl moieties display such high catalytic activity. [17,32] To investigate the source of the high GPx-like activity, a control experiment was carried out by using 6-Te-di-CD solution while adding an excess of adamantanecarboxylic acid. The GPx-like activity was estimated under the same condition as mentioned above, and the initial rate was found to be 15.9 Â 10 À6 mol Á L À1 Á min À1 (Figure 6c).…”