Cucurbit[7]uril and β-cyclodextrin as hosts for dopamine: complexation, affinity, and computational insights.

Dopamine (DP), an essential neurotransmitter implicated in diverse brain functions, was investigated as a guest molecule within the host cavities of cucurbit[7]uril (CB7) and β-cyclodextrin (βCD) using isothermal titration calorimetry (ITC), UV-titration, H NMR, molecular dynamics (MD) and density functional theory (DFT) calculations. The experimentally estimated binding constants of the 1:1 complexes of DP with CB7 and βCD were found to be 5.3 × 10 and 2.

Synthesis, biological evaluation, and computational studies of -benzyl pyridinium-curcumin derivatives as potent AChE inhibitors with antioxidant activity.

A library of -benzylpyridinium-based compounds, and , was designed and synthesised as potential acetylcholinesterase) AChE (inhibitors. An assay for the synthesised compounds showed that most compounds had significant AChE inhibitory activities at the nanomolar and submicromolar levels. The benzyl () and fluoro () derivatives were the most active, with IC values ≤56 nM.

Binary and Ternary Complexes of Cucurbit[8]uril with Tryptophan, Phenylalanine, and Tyrosine: A Computational Study.

Selective binding of amino acids, peptides, and proteins by synthetic molecules and elucidation of the geometry and dynamics of the resulting complexes and their strengths are active areas of contemporary research. In recent work, we analyzed via molecular dynamics (MD) simulations the complexes formed between cucurbit[7]uril (CB7) and three aromatic amino acids: tryptophan (W), phenylalanine (F), and tyrosine (Y). Herein, we continue this line of research by performing MD simulations lasting 100 ns to investigate the formation, stabilities, binding modes, dynamics, and specific host-guest noncovalent interactions contributing to the formation of the binary (1:1) and ternary (2:1) complexes in aqueous solution between W, F, and Y amino acids and cucurbit[8]uril (CB8).

Elucidation of the Controlled-Release Behavior of Metoprolol Succinate from Directly Compressed Xanthan Gum/Chitosan Polymers: Computational and Experimental Studies.

The development and evaluation of a controlled-release (CR) pharmaceutical solid dosage form comprising xanthan gum (XG), low molecular weight chitosan (LCS), and metoprolol succinate (MS) are reported. The research is, partly, based upon the utilization of computational tools: in this case, molecular dynamics simulations (MDs) and the response surface method (RSM) in order to underpin the design/prediction and to minimize the experimental work required to achieve the desired pharmaceutical outcomes. The capability of the system to control the release of MS was studied as a function of LCS (% w/w) and total polymer (LCS and xanthan gum (XG)) to drug ratio (P/D) at different tablet tensile strengths.

Encapsulation of ionic liquids inside cucurbiturils.

Cucurbit[n]urils (CBn, n = 6-8) serve as molecular receptors for imidazolium-based ionic liquids (ILs) in aqueous solution. The amphiphilic nature of 1-alkyl-3-methylimidazolium guests (Cnmim), with a cationic imidazolium residue and a hydrophobic alkyl chain, enabled their complexation with CBn through a combination of the hydrophobic effect and ion-dipole interactions. 1H NMR experiments revealed that the cavity of CBn can host the hydrophobic chain of the ILs, while one of the carbonyl rims served as a docking site for the imidazolium ring.

Effect of Protonation State and N-Acetylation of Chitosan on Its Interaction with Xanthan Gum: A Molecular Dynamics Simulation Study.

Hydrophilic matrices composed of chitosan (CS) and xanthan gum (XG) complexes are of pharmaceutical interest in relation to drug delivery due to their ability to control the release of active ingredients. Molecular dynamics simulations (MDs) have been performed in order to obtain information pertaining to the effect of the state of protonation and degree of -acetylation (DA) on the molecular conformation of chitosan and its ability to interact with xanthan gum in aqueous solutions. The conformational flexibility of CS was found to be highly dependent on its state of protonation.

Structure-activity relationship of novel series of 1,5-disubstituted tetrazoles as cyclooxygenase-2 inhibitors: Design, synthesis, bioassay screening and molecular docking studies.

A novel class of modified 1,5-disubstituted tetrazoles was designed and synthesized, their biological activity as cyclooxygenases inhibitors was screened, and their molecular docking studies were performed. The structural modifications of the first category included the 4-methylsulfonyl phenyl at C-1 of the central moiety and the linkers (-OH, -CH2OH, -CH2CH2OH) with different lengths at the para position of the N-1 phenyl group. For the second category, the 4-methylsulfonyl phenyl group at C-1 was replaced with 4-aminosulfonyl phenyl.

Water dynamics in water/DMSO binary mixtures.

The dynamics of dimethyl sulfoxide (DMSO)/water solutions with a wide range of water concentrations are studied using polarization selective infrared pump-probe experiments, two-dimensional infrared (2D IR) vibrational echo spectroscopy, optical heterodyne detected optical Kerr effect (OHD-OKE) experiments, and IR absorption spectroscopy. Vibrational population relaxation of the OD stretch of dilute HOD in H(2)O displays two vibrational lifetimes even at very low water concentrations that are associated with water-water and water-DMSO hydrogen bonds. The IR absorption spectra also show characteristics of both water-DMSO and water-water hydrogen bonding.

Derivatization of 2-chlorophenol with 4-amino-anti-pyrine: a novel method for improving the selectivity of molecularly imprinted solid phase extraction of 2-chlorophenol from water.

Molecularly imprinted polymer (MIP) may not selectively recognize small template of limited number of functional groups, such as 2-chlorophenol (2-CP). In this work, a novel method was proposed to improve the recognition ability of the molecularly imprinted solid phase extraction (MISPE) of 2-CP from environmental waters. This was achieved by derivatization of 2-CP with 4-amino-anti-pyrine (4-AAP) to enlarge its molecular size and add more binding sites.

Novel inclusion complex of ibuprofen tromethamine with cyclodextrins: physico-chemical characterization.

Guest-host interactions of ibuprofen tromethamine salt (Ibu.T) with native and modified cyclodextrins (CyDs) have been investigated using several techniques, namely phase solubility diagrams (PSDs), proton nuclear magnetic resonance ((1)H NMR), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffractometry (XRPD), scanning-electron microscopy (SEM) and molecular mechanics (MM). From the analysis of PSD data (A(L)-type) it is concluded that the anionic tromethamine salt of ibuprofen (pK(a)=4.

Sorption of Zn(II), Pb(II), and Co(II) using natural sorbents: equilibrium and kinetic studies.

Natural Jordanian sorbent (consisting of primary minerals, i.e., quartz and aluminosilicates and secondary minerals, i.