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• Computational and experimental work has been performed on cocrystal of hydrochlorothiazide (HCTZ) and nicotinamide (NCT). • H-bonding interaction was studied by using monomeric, dimeric and trimeric models of HCTZ-NCT cocrystal. • NH 2 and C = O groups were involved in neighbouring hydrogen bonding interactions. • QTAIM and NBO analysis were done to explore inter and intramolecular H-bond interactions. • MEPS was performed to observe the reactive sites of the molecules. The present work focuses on the study of structural, vibrational, chemical properties and the effect of hydrogen bonding interaction in the formation of a cocrystal of hydrochlorothiazide (HCTZ, a diuretic drug) with nicotinamide (NCT) using vibrational spectroscopy (FT-IR and FT-Raman) and density functional theory. HCTZ being a BCS class IV drug, has low permeability and solubility; therefore, its cocrystal is studied. Monomer, dimer and trimer of HCTZ-NCT cocrystal were studied to understand hydrogen bonding interactions. The shifting in the wavenumber and the elongation in bond lengths of the amide (NH 2) group of HCTZ and carbonyl (C = O) group of NCT were observed in all the models of HCTZ-NCT cocrystal due to the hydrogen bonding interaction. The importance of hydrogen bonding were also explored by natural bond orbital (NBO) analysis in support of the quantum theory of atom in molecules (QTAIM). The chemical reactivity of HCTZ, NCT and HCTZ-NCT cocrystal was examined by MEPS map, FMOs, global electronic reactivity descriptor, ECT descriptors, and molar refractivity. The lesser value of the HOMO-LUMO energy gap in the cocrystal than API reflects that the chemical reactivity of the cocrystal was better than API itself. The comparison between API(HCTZ) and cocrystal (HCTZ-NCT) implies that pharmaceutical cocrystals may be a better option to improve and enhance the pharmacological properties of drugs. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Optimized structure monomer and dimer structures of A10 DLC using DFT. • Microscopic molecular dynamics were revealed through FT-IR, FT-Raman, and DFT. • Predicted the mesomorphic models of nematic and columnar of A10. • QTAIM analysis predicts the strength and nature of hydrogen bonding. Utilizing temperature-dependent Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectroscopies, we delved into the spectral properties of 4-((2,3,4-tris(decyloxy)phenyl)diazenyl)benzoic acid, a fascinating discotic liquid crystal (DLC) named A10. Our investigation unravels valuable insights into conformational dynamics, intermolecular hydrogen bonding, and structural stability, throughout enantiotropic phase transitions (Isotropic (Iso) → Discotic Nematic (N D) → Columnar (Col) → Crystalline (Cry)) during cooling. To further understand the mesogen's phasmid structure at atomic level, density functional theory (DFT) is employed, utilizing the B3LYP/6-3116G(d,p) method for optimization and frequency calculations of monomer and dimer of A10. The alignment of computationally predicted molecular models with observed vibrational spectra at room temperature affirms the precision of our theoretical model. Innovatively, our study has uncovered the potential formation of dimer assemblies, demonstrating the persistence of intermolecular hydrogen bonding within these dimers throughout each phase transition of the DLC. Furthermore, we have identified the strength of both intermolecular and intramolecular hydrogen bonding. These findings expand our knowledge of this unique material and pave the way for further research in the field of liquid crystals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Monomeric and dimeric structure of discotic liquid crystal (DLC) A8 is optimized using density functional theory (DFT). • Phase transition of DLC A8 (Isotropic → Discotic nematic → Columnar → Crystalline) have been analysed with the help of temperature dependent FT-IR and FT- Raman spectra. • Combination of experimental (FT-IR and FT-Raman) and computational results allow us to elucidate the dynamics of the molecules during the phase transitions. • AIM analysis has predicted the strength and nature of the inter and intra molecular hydrogen bonding in DLCs. The discotic liquid crystal 4-((2, 3, 4-tris (octyloxy) phenyl) diazenyl) benzoic acid , hereafter referred as DLC A8, exhibited in dimeric form has been studied using a combination of quantum chemical approaches and vibrational spectroscopy. This study investigates the structural alteration of DLC A8 associated with phase transition. The phase transitions of DLC A8 are Iso → Discotic nematic → Columnar → Crystalline, which have been investigated using differential scanning calorimetry (DSC) accompanied with polarized optical microscopy (POM). Monotropic columnar mesophase was observed during the cooling cycle while discotic nematic mesophase was observed in both the heating and cooling cycles. Density functional theory (DFT) along with IR and Raman spectroscopic techniques were utilized to study the dynamics of molecules during phase transition. To predict the most stable conformation of the molecule, one-dimensional PES scans have been performed along 31 flexible bonds using DFT/B3LYP/6-311G++(d,p) method. Vibrational normal modes were analyzed in detail, taking potential energy contribution into account. The spectral analysis of FT-IR and FT-Raman was done by deconvoluting the structural sensitive bands. The agreement between the calculated IR and Raman spectra and the observed FT-IR and Raman spectra at room temperature confirms our theoretically predicted molecular model of investigated discotic liquid crystal. Moreover, our studies have unraveled the existence of intact intermolecular H-bonding of dimers throughout the phase transitions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Computational and experimental work has been performed on hydrochlorothiazide (HCTZ). • H-bonding interaction was studied using monomeric, dimeric and trimeric models. • NH 2 and O S O groups were involved in neighboring interactions. • QTAIM and NBO analysis was done to explore inter and intramolecular H-bond interactions. Hydrochlorothiazide (HCTZ) being a diuretic drug widely used in anti-hypertensive therapy as it lowers the blood pressure by reducing the reabsorption of electrolytes in kidney resulting an increment of urine output and lowering the blood pressure. The purpose of the present work is to study the structural, vibrational and chemical properties of HCTZ based on its monomeric, dimeric and trimeric models by utilizing computational methods and experimental techniques. Density functional theory (DFT) with functional B3LYP and 6-311++G (d, p) basis set was used for a detailed computational study. Monomeric, dimeric and trimeric models of HCTZ have been studied for a better understanding of inter- and intramolecular hydrogen bonding. FT-IR (400–3800 cm−1) and FT-Raman (100–3600 cm−1) spectroscopy have been utilized for the characterization of HCTZ. The shifting in wavenumber of NH 2 and O S O group were observed in dimer and trimer due to the formation of intermolecular hydrogen bonding. Quantum theory of atoms in molecules (QTAIM) along with natural bond orbital (NBO) analysis were performed to examine the nature and strength of hydrogen bonding which showed that all the interactions were medium and partially covalent in nature; transition from LP(3)O15 → σ*(H46 → N32) and LP(3)O39 → σ*(H74 → N51) were responsible for the formation of O15•••H46 and O39•••H74 H-bonds, respectively. HOMO-LUMO energies predicted the chemical reactivity and stability of the molecule and the energy gap for dimer (4.6240 eV) and trimer (4.0493 eV) was found to be lesser than the monomer (5.0888 eV) which showed that the dimer and trimer have predicted more chemical reactivity in comparison to monomer. The most electronegative electrostatic potential was observed around the O S O group and the most electropositive potential around the amide group from MEPS analysis. Global as well as local reactivity descriptors have predicted the reactivity and hence, stability of the title molecule. [ABSTRACT FROM AUTHOR]

Vector-borne haemoparasitic diseases of migratory small ruminants have been less explored to date. Therefore, transhumant migratory sheep and goats of the Himalayas were molecularly screened for various vector-borne pathogens like Anaplasma, Theileria , Babesia , Anaplasma marginale , Theileria luwenshuni , Theileria orientalis, and Trypanosoma evansi using their specific primers. Out of the 171 animals screened, 73.09% of the animals were infected with Anaplasma spp. and 74.85% of the animals with Theileria spp., while no animals were found infected with Babesia spp. and Trypanosoma evansi. In a quest to identify the species, a few positive PCR amplicons representing Anaplasma spp., Theileria spp., and Theileria/Babesia spp. were sequenced. The sequences obtained were further BLAST analyzed to reveal maximum identity with Anaplasma capra (100%), Theileria luwenshuni (99.71%), and Theileria sinensis (98.73%). Among them Theileria luwenshuni was further confirmed with their species-specific PCR and the positive amplicons were sequenced and BLAST analysed to reveal their maximumsimilarity with Chinese isolates rather than Indian isolates. Further, phylogenetic analyses of the resulting sequences were conducted to identify their evolutionary history. It revealed that 1100 bp- amplicons of Theileria spp. were showing maximum likeness to Theileria sp. MK, a non-transforming Theileria. This is the first report of zoonotic Anaplasma capra and Theileria sp. MK in small ruminants from India and it could be mostly due to their transboundary migration history through the Indo-Tibetan border during summer seasons as a part of the traditional migratory system of livestock rearing practice in the Himalayas. The high prevalence of haemoparasites in migratory small ruminants calls for the adoption of effective control measures. • First report of Anaplasma capra , Theileria sp. MK from migratory small ruminants of India. • Anaplasma capra is zoonotic and therefore demands utmost attention. • Theileria sp. MK is a non-transforming Theileria closely related to Theileria orientalis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption energy, UV–Visible spectrum, Reduced Density Gradient (RDG), HOMO-LUMO gap were calculated for all systems. • The Au7Cu nanoclusters and their complexes with glycine have maximum HOMO-LUMO gap therefore they have more stability or less reactivity in comparison to the other nanoclusters in this work. • The maximum adsorption energy is found in the small copper doped gold nanoclusters [Au 4 Cug(A,B)] and in spherically shaped thirteen atoms nanoclusters [Au 12 Cug(C)]. • Five and fifteen-atom nanoclusters could be observed red shift and eight, thirteen, and eighteen atoms and their complexes have shown a blue shift in the UV–Visible spectra when glycine is adsorbed on Cu doped Au nanoclusters. Gold nanoclusters and bimetallic gold nanoclusters are interesting areas of research. These nanoclusters are used for the detection of organic molecules, cancer treatment, bio-imaging, drug delivery etc. In this paper, we studied the interaction of copper doped Au nanoclusters of five, eight, thirteen, fifteen, and eighteen atoms with glycine amino acid. Their HOMO-LUMO gap, adsorption energy, non-covalent interaction, hardness, electrophilicity index, electrochemical potential, and UV–Visible spectra were analyzed. The maximum adsorption energy is found in the nanoclusters Au 4 Cug(A,B) and Au 12 Cug(C). Additionally, strong non-covalent interaction is observed in the Au 4 Cug(A,B) and Au 12 Cug(B) nanoclusters, which makes them suitable for applications like drug delivery, biosensing etc. These nanoclusters are also more stable compared to other nanoclusters in this work (only exception Au 7 Cu(A,B,C)) owing to their large HOMO-LUMO gap and symmetric structure. [ABSTRACT FROM AUTHOR]