Browsing by Subject "Biologically Active Molecules"

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Open Access
Assorted interactions of some noteworthy compounds prevailing in host guest and solution chemistry investigated by physicochemical contrivance
(University of North Bengal, 2024) Debnath, Subhajit; Nath Roy, Mahendra; Sinha, Anuradha
By the thesis title, I aim to demonstrate my profound understanding of the fields of amino acid-ionic liquid as well as vitamin-ionic liquid interaction in aqueous medium and supramolecular host-guest inclusion complexation. The supramolecular assembly has become increasingly important in drug release these days because of its exceptional bioavailability and unique capacity to change the solubility, stability, pharmacokinetics, and pharmacodynamics of the medication. They also show improved encapsulation, controlled release, and benign qualities. The inclusion complexation of diverse bioactive compounds and their distinct photophysical properties in aqueous media are confirmed by the spectroscopic contribution. The development of supramolecular assembly can be qualitatively understood by the use of SEM analysis, powder XRD, 1H-NMR, FTIR, and UV-visible analysis, all of which can satisfactorily express the inclusion phenomenon. Studying TGA and DSC can help to explain why such an arrangement is thermally stable. Confirming the data from the experimental research are studies of the supramolecular system using theoretical molecular modeling. Significant information on a variety of thermodynamic properties of electrolytes and non-electrolytes, the impacts of variations in ionic structures, and the mobility of ions in addition to their common ions can be gained from the study of the physicochemical properties of solutions. Measurements of apparent molar volume ( v  ), limiting apparent molar volume ( 0 v  ), molar refraction ( M R ), limiting molar refraction ( 0 M R ), molar conductance (Ʌ), Surface tension (γ) and viscosity B coefficients obtained from various physicochemical methodologies are typically used to reveal the genesis of diverse interactions between amino acids, vitamins and ionic liquid in the aqueous phase. This study has looked at the encapsulation of several biologically active compounds. There may be uses for these bioactive compounds in biological systems. Pharmacological activity is frequently used to characterize the advantageous properties of bioactive compounds. In host–guest chemistry, the application of macrocyclic hosts in molecular recognition, controlled release of a drug and sensing field has received considerable interest. The incorporation of guest molecules in the aqueous environment within the cavity of the host molecule such as α-cyclodextrin, provides new insight into molecular recognition (e.g. inclusion or complexation) through non-covalent interactions. A general understanding of the development of an inclusion complex between the host and guest molecules can be obtained from supramolecular host-guest chemistry. The host's hydrophobic cavities can bind various guest compounds. The supramolecular assembly as a whole has been extensively researched recently in a variety of disciplines, including analytical chemistry and medication delivery. When combined with different guest molecules of the right size, cyclodextrin and its derivative appear to be the most promising host molecules for the formation of inclusion complexes. Thus, the main goal of this thesis is to investigate the impact of supramolecular recognition and solution chemistry, which are unavoidably important due to their numerous applications in a variety of sectors, including the biological and pharmaceutical sciences. SUMMARY OF THE WORKS CHAPTER I This chapter includes a full description of the research project, its scope, and its applications to modern science. It also explains the rationale for the selection of solvent systems, cyclodextrins, ionic liquids, and bioactive compounds. A summary of all the investigation techniques used in the research project is provided in this chapter. CHAPTER II The earlier study on this topic, conducted by different scientists and researchers worldwide, is reviewed in this chapter. Additionally, a detailed explanation of the findings is provided in this chapter, which describes the forces that interact between the molecules. The theory underlying each of the investigation techniques—1H-NMR, FTIR, UV-visible, Differential Scanning Calorimetry, Thermogravimetric analysis, Powder XRD, Scanning Electron Microscopy, Molecular Docking study, Antimicrobial study, Cytotoxicity study, Surface Tension, Conductivity, Density, Viscosity, and Refractive Index has been covered in detail here, along with the importance of their application to the research described in this thesis. CHAPTER III The experimental section is covered in this chapter. It discusses the names, compositions, characteristics, and uses of cyclodextrin, ionic liquids, solvents, and biologically active compounds that are employed in research projects. It also contains information about the instruments used in this research, their descriptions, and the specifics of the experimental procedures. CHAPTER IV This chapter consists of the formation of the new inclusion complex between the 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [Bdmim]BF4 ionic liquid (IL) and the host α-Cyclodextrin (α-CD) by a 1:1 ratio and newly formed inclusion complex was further explored by the 1H-NMR, FT-IR, UV-vis spectroscopy, PXRD, DSC, and SEM analysis. Molecular docking was also performed to investigate the encapsulation of the inclusion complex in which orientation and it have been seen that the IL [Bdmim]BF4 enters into the α-CD cavity with a 1:1 ratio. It was further established with the help of Job’s plot. The antibacterial activity of [Bdmim]BF4 IL and its inclusion complex was also verified against some Gram-positive and Gram-negative bacterial strains. *Published in Zeitschrift für Physikalische Chemie, 2023 CHAPTER V This chapter includes investigating the encapsulation of polyether compounds such as mephenesin (MEP) into the nano hydrophobic cage of α-cyclodextrin as a host molecule. The consequential inclusion system was characterized by UV−visible spectroscopy, 1H NMR, PXRD, TGA, DTA, SEM, and FTIR studies. Molecular docking was performed for the inclusion complex to discover the most proper orientation, and it was seen that the drug mephenesin fits into the cavity of α-cyclodextrin in a 1:1 ratio, which was also confirmed from the Job plot. Furthermore, a comparison was done based on cell viability between the drug and its inclusion complex *Communicated. CHAPTER VI This chapter includes the solute–solvent interaction between ionic liquids (ILs) and amino acids (AA) in aqueous media plays a significant role in the optimization of several important biotechnological processes. L-Phenylalanine and LTryptophan (two solute molecules) interact with an ionic liquid (Benzyltributylammonium chloride) in an aqueous medium. Based on the different parameters such as apparent molar volume, viscosity B-coefficient, molar refraction, molar conductance, surface tension at different temperatures and different concentrations from density, viscosity, refractive index, conductance, surface tension measurements have been used to explain the molecular level interactions. Using Masson equation, the experimental slopes and the limiting apparent molar volumes are obtained which explain the solute-solute and solute-solvent interactions. Hepler’s technique and dB/dT values have been used to examine the structure-making and structure-breaking nature of the solutes in the solvents. Viscosity parameters, A and B obtained from Jones- Doles equation explained the solute-solute and solute-solvent interactions in the solution. Lorentz-Lorenz equation has used to calculate the molar refraction. The specific conductance and surface tension also explained the interaction properties. In our findings, we emphasized on the nature of solute–solvent interactions and the presence of structural effect on the solvent in solution to analyze the molecular-level interactions prevalent in the systems. *Published in World Journal of Engineering Research and Technology, 2021 CHAPTER VII In this chapter the densities, viscosities, conductances and surface tension of Vitamin C (Ascorbic acid) in Ionic Liquids viz: Benzyltributylammonium chloride (BTBAC) and Benzyltriethylammonium chloride (BTEAC) aqueous mixtures have been measured at 298.15K, 308.15K and 318.15 K. Apparent molar volumes (Фᴠ), viscosity Bcoefficients, molar conductances are obtained from these data supplemented with densities, viscosities and specific conductances, respectively. The limiting apparent molar volumes (Фᴠ0) and experimental slopes (SV*) derived from the Masson equation have been interpreted in terms of solute-solvent and solute-solute interactions, respectively. The viscosity data have been analyzed using the Jones-Dole equation, and the derived parameters B and A have also been interpreted in terms of solute-solvent and solutesolute interactions, respectively. The surface tension parameter has also been utilized to support the investigation. The structure-making/breaking capacities of ascorbic acid in the studied ionic liquid systems have also been discussed. *Published in Journal of Chemical, Biological and Physical Sciences, 2024 CHAPTER VIII This chapter includes the concluding remarks about the research works done in this thesis. CHAPTER IX Bibliography and references of all the previous chapters has been included in this chapter.
Open Access
Experimental and computational studies of various interactions of some significant compounds prevailing in solutions and inclusion complexes by different methedology
(University of North Bengal, 2024) Karmakar, Paramita; Roy, Mahendra Nath; Ekka, Deepak
The focus of this thesis is to delve deeply into the realm of Supramolecular Host-Guest Inclusion Complexation and the interaction between Food Chemicals and Ionic Liquid along with vitamins with caffeine solution in the solution phase, culminating in molecular synergism that enhances microbial activity. In the field of supramolecular chemistry, biologically potent molecules such as drugs, and bio-active molecules, which are often water-soluble with underdeveloped delivery systems, were selected to form inclusion complexes with cyclodextrins. The objective is to improve solubility and bioavailability. The research employs various physicochemical and spectroscopic methodologies to investigate the mechanisms behind the formation, stability, thermodynamic feasibility, binding ability to albumin protein, and sustained release of drug molecules from inclusion complexes into the surrounding medium. In the context of solution chemistry, first, the interaction between Food chemicals and Ionic Liquid demonstrates molecular synergism. This aspect holds great importance in food chemistry, considering the substantial global food production and the associated challenges of spoilage. The investigation of diverse interactions involves measuring apparent molar volume (φv), limiting apparent molar volume (φv 0), molar refraction (RM), and limiting molar refraction (RM 0). These parameters are obtained through various physicochemical methodologies. My research in supramolecular chemistry is substantiated by the successful advancement of the following novel aspect: (a) Improvement of drug solubility in water to enhance bioavailability (b)Controlled drug delivery facility (c) Enhancement of antioxidant activity (d) Facilitation of cyto-toxicity (e) Augmentation of antimicrobial activity For a drug to exhibit heightened therapeutic effectiveness, achieving substantial bioavailability and solubility is crucial. The pharmacological response necessitates the drug to attain a minimum concentration, underscoring the significance of reaching a desired level of aqueous solubility. A molecule's solubility is qualitatively defined as the spontaneous interaction of two or more substances, resulting in a homogeneous molecular dispersion. Through experimentation, it was discovered that the formation of drug-cyclodextrins (CDs) inclusion complexes significantly enhances the aqueous solubility of the drug, thereby increasing its bioavailability. This enhancement is attributed to the encapsulation of the hydrophobic segment of the guest molecule within the hydrophobic cavity of appropriately sized CDs. The cavity dimensions of the CDs play a crucial role, as they should be moderate enough to minimize contact between water and the nonpolar regions of both the host and guest molecules. Notably, α and β- cyclodextrins were selected due to the dimensional suitability of their cavity sizes in this context. Summary of work done CHAPTER I This chapter provides a comprehensive exploration of the research work's subject matter, elucidating its scope and applications in modern science. It delves into the rationale behind selecting bio-active molecules, drugs, vitamins, nerve stimulating chemicals, food food chemicals, ionic liquids, cyclodextrins, and solvent systems for study. CHAPTER II This chapter presents a comprehensive review of prior research conducted by scientists and researchers globally in the relevant field. It also provides a detailed theoretical framework for the investigation, elucidating the forces that interact between molecules. The chapter extensively discusses the theories and applications of various analytical techniques such as 1H NMR, 2D ROESY, FTIR spectroscopy, UV-Visible spectroscopy, Scanning Electron Microscopy, Powder X-Ray Diffraction, High- Resolution Mass Spectroscopy, computational study, Conductivity, Density, Viscosity, and Refractive Index. It underscores the significance of employing these methods in the research conducted within this thesis. CHAPTER III This chapter encompasses the experimental aspects, detailing the nomenclature, structure, physical attributes, purification methods, and applications of biologically active molecules, drugs, vitamins, cyclodextrins, food chemicals, ionic liquids, and solvents employed in the research. Additionally, it provides comprehensive information on the experimental methods, including descriptions and applications of the instruments utilized in the research. CHAPTER IV This chapter includes an investigation on the diverse molecular interactions between implausible food chemicals (potassium oxalate, sodium oxalate and lithium Oxalate) and 1-butyl-1-methyl-pyrrolidinium chloride in aqueous solutions has been presented. The experiments have been discovered thoroughly by different types of physicochemical methodologies like density, refractive index, viscosity, and conductivity at three different temperatures 298.15K, 308.15K and 318.15K. The genesis of diverse interactions of the ternary mixtures were exposed by measurement of the apparent molar volume (φv), limiting apparent molar volume (φv 0), viscosity B coefficients, molar refraction (RM), limiting molar refraction (RM 0). The results have revealed the predominant solute-solvent interaction over the solutesolute as well as solvent-solvent interactions. The ionic liquid is more strongly interacting with potassium oxalate than sodium oxalate, which in turn is greater than lithium oxalate at a higher range of temperature. Moreover, Density functional theory calculations were performed to evaluate parameters like adsorption energies, molecular electrostatic potential maps and mode of binding which corroborate the experimental observations. CHAPTER V This chapter consists of encapsulation of Nicotinuric acid in the cavity of cyclodextrins. Nicotinuric acid is an agent in the pathogenic mechanism for metabolic syndrome to diabetes and atherosclerotic cardiovascular disease. To protect these external effects (e.g., oxidation, structural modification etc), a systematic study of hostguest complexation of nicotinuric acid with α and β-cyclodextrins has been incorporated. The analysis has been empowered by Spectroscopic study like UV-Vis, FTIR, 2D ROESY NMR, and SEM. Job’s plot by UV-vis spectral data shows 1:1 stoichiometric combination of nicotinuric acid and cyclodextrin. The noticeable shifts in FTIR stretching frequency also assisted the inclusion phenomenon. The reliable magnitude of the association constants (8.27×103 & 8.84×103 in α-CD and β-CD respectively), obtained from Benesi-hildebrand method, is in good agreement with the stabilities of the inclusion phenomena. In 2D ROESY analysis three offdiagonal peaks are observed due to the intermolecular dipolar cross correlation between the proton of the pyridinium ring of nicotinic acid with the H3 and H5 of α and/or β- CD. Surface morphologies from SEM of the complexes have also been added. Molecular docking has been carried out to explore the fitting mechanism of NUA insight into the cavity of CDs. The guest scores -6.1 kJ/mol and -6.4 kJ/mol with α-CD and β-CD respectively. CHAPTER VI In this paper, Volumetric and viscometric analysis of ascorbic acid and thiamine hydrochloride in caffeine aqueous solution at different mass fractions over the temperature range (298.15K -318.15K) and at 1 atm pressure, have been implemented. All analyses have been interpreted in terms of solute–solute, solvent–solvent and solute-solvent interactions of the considered system. The parameters like apparent molar volume(φv) and limiting apparent molar volume (φv 0), have been estimated from the density data. Falkenhagen A-coefficients and Viscosity B-coefficients have been predicted from viscosity by implementing the Jones-Dole equation. The Hepler’s constant and RM have been evaluated. DFT calculation predicts the mode of binding which correlates the practical observations. By the help of physicochemical and computational techniques, we found that vitamins behave as structure breaker in caffeine solution. CHAPTER VII In this paper, Esculetin and α-cyclodextrin, as well as beta-cyclodextrin host molecules, have been intermixed with the help of the coprecipitation method to form a supramolecular complex to offer physical insights into the formation and stability of the inclusion complex (IC). The characterization of the synthesized product was done by Powder X-ray diffraction (XRD), electrospray ionization mass spectrometry (ESIMS), 1H nuclear magnetic resonance (1H NMR), Fourier transform infrared (FTIR) spectroscopy, electrospray ionization (ESI) mass spectrometry, Scanning Electron Microscopy (SEM). The stoichiometric ratio of 1:1 is obtained from Job Plot and the Benesi−Hildebrand double reciprocal plot provides the association constant values supported by the ESI mass data. The inclusion complexation is validated by the systematically analyzed results of molecular modeling, additionally, the outcomes achieved from 1H NMR and FTIR spectroscopy studies which reinforce the complexation phenomenon. The encapsulation of Esculetin into α-cyclodextrin along with beta-cyclodextrin is determined by the results acquired from computations in addition to experimental data. CHAPTER VIII This chapter includes the concluding remarks about the research works done in this thesis.
Open Access
Synthesis and characterisation of host-guest inclusion complexes for better applications by physicochemical techniques
(University of North Bengal, 2022-06) Bomzan, Pranish; Roy, Mahendra Nath