12 research outputs found
Dynamic and Assembly Characteristics of Deep-Cavity Basket Acting as a Host for Inclusion Complexation of Mitoxantrone in Biotic and Abiotic Systems
We describe the preparation, dynamic, assembly characteristics of vase-shaped basket 13ā along with its ability to form an inclusion complex with anticancer drug mitoxantrone in abiotic and biotic systems. This novel cavitand has a deep nonpolar pocket consisting of three naphthalimide sides fused to a bicyclic platform at the bottom while carrying polar glycines at the top. The results of 1H Nuclear Magnetic Resonance (NMR), 1H NMR Chemical Exchange Saturation Transfer (CEST), Calorimetry, Hybrid Replica Exchange Molecular Dynamics (REMD), and Microcrystal Electron Diffraction (MicroED) measurements are in line with 1 forming dimer [12]6ā, to be in equilibrium with monomers 1(R)3ā (relaxed) and 1(S)3ā (squeezed). Through simultaneous line-shape analysis of 1H NMR data, kinetic and thermodynamic parameters characterizing these equilibria were quantified. Basket 1(R)3ā includes anticancer drug mitoxantrone (MTO2+) in its pocket to give stable binary complex [MTOā1]ā (Kd=2.1 Ī¼M) that can be precipitated in vitro with UV light or pH as stimuli. Both in vitro and in vivo studies showed that the basket is nontoxic, while at a higher proportion with respect to MTO it reduced its cytotoxicity in vitro. With well-characterized internal dynamics and dimerization, the ability to include mitoxantrone, and biocompatibility, the stage is set to develop sequestering agents from deep-cavity baskets
Reactivity of Organic Compounds Inside Micelles Embedded in SolāGel Glass. Kinetics of Isomerization of Azobenzene Inside CTAB and SDS Micelles Embedded in Silica Matrix
Effects of Encapsulation in SolāGel Silica Glass on Esterase Activity, Conformational Stability, and Unfolding of Bovine Carbonic Anhydrase II
Unexpected Interactions between SolāGel Silica Glass and Guest Molecules. Extraction of Aromatic Hydrocarbons into Polar Silica from Hydrophobic Solvents
Multivalency and Cooperativity in Supramolecular Chemistry
Multivalent interactions, which rely upon noncovalent bonds, are essential ingredients in the mediation of biological processes, as well as in the construction of complex (super)structures for materials applications. A fundamental understanding of multivalency in supramolecular chemistry is necessary not only to construct motors and devices on the nanoscale but also to synthesize model systems to provide insight into how biological processes work. This Account focuses on the application of multivalency to supramolecular chemistry in particular and the nanosciences in general
Multivalency and Cooperativity in Supramolecular Chemistry
Multivalent interactions, which rely upon noncovalent bonds, are essential ingredients in the mediation of biological processes, as well as in the construction of complex (super)structures for materials applications. A fundamental understanding of multivalency in supramolecular chemistry is necessary not only to construct motors and devices on the nanoscale but also to synthesize model systems to provide insight into how biological processes work. This Account focuses on the application of multivalency to supramolecular chemistry in particular and the nanosciences in general
On the mechanism of action of gated molecular baskets: The synchronicity of the revolving motion of gates and in/out trafficking of guests
We used dynamic 1H NMR spectroscopic methods to examine the kinetics and thermodynamics of CH3CCl3 (2) entering and leaving the gated molecular basket 1. We found that the encapsulation is first-order in basket 1 and guest 2, while the decomplexation is zeroth-order in the guest. Importantly, the interchange mechanism in which a molecule of CH3CCl3 directly displaces the entrapped CH3CCl3 was not observed. Furthermore, the examination of the additivity of free energies characterizing the encapsulation process led to us to deduce that the revolving motion of the gates and in/out trafficking of guests is synchronized, yet still a function of the affinity of the guest for occupying the basket: Specifically, the greater the affinity of the guest for occupying the basket, the less effective the gates are in āsweepingā the guest as the gates undergo their revolving motion
Stereo- and regioselective halogenation of norbornenes directed by neighboring group participation
Assembly of Amphiphilic Baskets into Stimuli-Responsive Vesicles. Developing a Strategy for the Detection of Organophosphorus Chemical Nerve Agents
We designed basket 1 to comprise a C-3-symmetric hydrophobic cage (477 angstrom(3)) at its southern edge and three polar ammonium caps at the northern edge. This amphiphilic molecule was observed to assemble into large unilamellar vesicles (350 nm, TEM) in water and thereby entrap dimethyl phenylphosphonate (184 angstrom(3)) in its cavity (K-app = (1.97 +/- 0.02) X 10(3) M-1). The entrapment of the organophosphonate, akin to soman in size (186 angstrom(3)), triggers the transformation of the vesicular material into nanoparticles (100 nm,of type 1 in their bilayer membrane, are unique assemblies and important for obtaining novel sensing devices.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3469