Rajaram Rajamohan

Host–guest interaction of l-tyrosine with β-cyclodextrin

The inclusion complexes of beta-cyclodextrin (beta-CD) with L-tyrosine (L-TYN) were investigated by using spectrophotometers. The absorption and fluorescence enhancement occurs with beta-CD and L-TYN forms 1:1 inclusion complex. The unusual blue shift of hydroxyl ion in the beta-CD medium confirms OH groups present in the interior part of the beta-CD cavity and -COOH group present in the upper part of the beta-CD cavity. A mechanism is proposed to explain inclusion process. The inclusion interaction was examined and the thermodynamic parameters of inclusion process DeltaG, DeltaH and DeltaS were determined. The results indicated that the inclusion process was an exergonic and spontaneous process. Stable solid inclusion complexes were established and characterized by FT-IR, scanning electron microscope (SEM) methods.

Effect of inclusion complexation on the photophysical behavior of diphenylamine in β-cyclodextrin medium: A study by electronic spectra

Spectral characteristics of diphenylamine (DPA) have been investigated in β-cyclodextrin (β-CDx) solution. The formation of the complex was revealed by UV, steady state and time-resolved fluorescence spectroscopy. The stoichiometry of DPA:β-CDx complex, determined using Benesi-Hildebrand equation and Jobs continuous variation method is 1:1. The binding constants calculated from various methods are reported. This inclusion complex formation from DPA and β-CDx was also confirmed by the FT-IR spectral study and SEM image analysis of solid complex prepared by co-precipitation method.

Preparation and characterization of a imipramine-ß-cyclodextrin inclusion complex

ABSTRACT This article characterizes the association between imipramine and ß-cyclodextrin. The formation of supramolecular host-guest inclusion complex of imipramine with the nano-hydrophobic cavity of ß-cyclodextrin was prepared by physical mixing and coprecipitation. The inclusion complex of imipramine and ß-cyclodextrin in solution was characterized by ultraviolet-visible and fluorescence spectroscopy. The inclusion complex was characterized by infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The spectral shifts showed that only a portion of the imipramine molecule was within the ß-cyclodextrin cavity. The binding constant and the 1:1 stoichiometry of the inclusion complex at 303 K was obtained using a Benesi-Hildebrand plot. The Gibbs free energy change of the complex formation process was determined and the complex formation was shown to be spontaneous. The changes observed in vibrational frequencies, morphology, diffraction, and thermal stability confirmed the formation of the solid inclusion complex. Molecular docking and semi-empirical studies were used to characterize the ß-cyclodextrin-associated inclusion complexes of imipramine. The results of molecular modeling were systematically analyzed to determine the stability of the complexes.

Spectral characteristics of desipramine in β-cyclodextrin cavity through inclusion complex

ABSTRACT The inclusion complexation behavior and its characterization of Desipramine (DP) with β-Cyclodextrin (β-CD) in solution phase are analyzed by UV and fluorescence spectroscopy. The solid inclusion complex is characterized by FT-IR, SEM, Powder XRD and TG/DTA. The stoichiometric ratio of the complexation is found to be 1:1. The orientation and structure of the complex are proposed based on the analysis of Patch-Dock server. The formation of inclusion complex has been confirmed on the base of the changes of spectroscopic properties will be encapsulated in partly either by any aromatic ring or by the aliphatic side chain. But our results showed that the aliphatic group of DP is in the cavity of β-CD.β-CD encapsulation and enhances the in-vitro cytotoxicityeffect of DP compound by forming inclusion complex in the solid state.

Host–guest complexation between 5-aminoisoquinoline and β-cyclodextrin and its effect on spectral and prototropic characteristics

The effects of the addition of β-cyclodextrin (β-CDx) on the absorption and emission properties of the 5-aminoisoquinoline (5AIQ) have been investigated in aqueous media. The formation of host–guest inclusion complex with 1:1 stoichiometry was revealed by absorption, steady state and time-resolved emission spectroscopy. The complex formation has also been confirmed by FT-IR spectra and SEM image analysis of the solid inclusion complex between 5AIQ and β-CDx. No significant change was observed in the ground and excited state pKa values in β-CDx medium. Based on photophysical and prototropic characteristics of 5AIQ in β-CDx, the structure of the 1:1 inclusion complex is proposed.

Improvement of cytotoxic activity of local anesthetics against human breast cancer cell line through the cyclodextrin complexes

ABSTRACT Among the potent anticancer agents, Local Anesthetics (LA) have been found to be efficient against many different types of cancer cells. However, the major disadvantage associated with the use of LA its low systemic bioavailability when administered due to its poor aqueous solubility. Our present work concentrates on improving the bio-availability by complexing with cyclodextrin. We synthesized the inclusion complexion by co-precipitation method which is an efficient method among other and characterized the formulation of complex by UV and fluorescence studies. The in-vitro study of cytotoxicity against breast cancer cell line is performed. Our study shows the formation of the complex with 1:1 ratio and the result show both Benzocaine and Tetracaine inclusion complex has higher potential towards breast cancer cell than the free drug.