Time series Fourier transform infrared spectroscopy for characterization of water vapor sorption in hydrophilic and hydrophobic polymeric films

Unlocking the medicinal arsenal of Cissus assamica: GC-MS/MS, FTIR, and molecular docking insights

Background and aims

This study investigated the biochemical components present in the leaves of Cissus assamica. The primary aim was to analyze these components using advanced techniques and assess their potential therapeutic applications.

Methodology

Fourier Transform Infrared (FT-IR) spectroscopy, Gas Chromatography-Mass Spectrometry (GC-MS), and Mass Spectral analysis were employed to identify and characterize the compounds in Cissus assamica leaves. The mass spectra of each compound were compared with data from the Wiley and NIST libraries to determine their names, molecular masses, and chemical structures. FT-IR analysis identified characteristic functional groups by their specific frequencies.

Results and discussion

FT-IR spectroscopic analysis revealed significant molecular vibrations at frequencies of 3265.63, 2853.81, 1638.60, 1469.21, and 1384.95 cm⁻¹, indicating the presence of specific functional groups. The GC-MS analysis identified distinct compounds, such as "aR-Turmerone," "Curlone," "7,8-Epoxylanostan-11-ol, 3-acetoxy-," "13-Docosenamide, (Z)-," "Phenol, 3,5-bis(1,1-dimethylethyl)-," "9,19-Cyclolanostan-3-ol, 24,24-epoxymethano-, acetate," and "Quinoline-5,8-dione-6-ol, 7-[[(4-cyclohexylbutyl)amino]methyl]-." These compounds exhibited potential therapeutic applications. Their cytotoxic, antimicrobial, antidiarrheal, anti-hyperglycemic, and pain-relieving properties were evaluated by comparing them with reference ligands targeting specific receptors, including dihydrofolate reductase (DHFR), epidermal growth factor receptor (EGFR), kappa opioid receptor (KOR), glucose transporter 3 (GLUT 3), and cyclooxygenase 2 (COX-2).

Conclusion

The results of this study suggest that Cissus assamica leaves contain bioactive compounds with potential therapeutic benefits for treating infections, diarrhea, hyperglycemia, and pain. However, further research is needed to conduct comprehensive phytochemical screening and establish the precise mechanisms of action for the crude extract or the plant-derived compounds.

Interfacial Water Molecules as Agents for Phase Change Control and Proton Conductivity Enhancement in the Ammonium Vanadyl Tartrate System

This study demonstrates the reversible structural transformation, single-crystal-to-single-crystal, of the ammonium vanadyl (L-tartrate) complex salt from the hydrate phase to the anhydrous phase. The transformation can be initiated by stimuli, such as temperature, humidity, or vacuum conditions. The hydrate and anhydrous phases exhibit a tetragonal structure (P41212), with marked differences in hydrogen bonding due to the presence or absence of one water molecule per asymmetric unit. The intricate relationship between crystal packing and intermolecular interactions in the hydrate phase was investigated by crystallographic charge density analysis revealing, at the molecular level, the reasons for the observed 5 orders of magnitude higher proton conductivity of the hydrate phase compared to that of the anhydrous phase. To gain further insight into the processes occurring at the surfaces of grain boundaries and the proton transfer mechanisms in this system, rehydration of the complex salt was carried out by using D2O instead of H2O and monitored by in situ ATR-FTIR spectroscopy. The results highlight the critical role of interfacial water molecules in driving structural transformations and influencing proton conductivity.

Vibrational Analysis of Hydration-Layer Water around Ubiquitin, Unpeeled Layer by Layer: Molecular-Dynamics Perceptions

Classical molecular-dynamics simulations have been performed to examine the interplay between ubiquitin and its hydration-water sub-layers, chiefly from a vibrational-mode and IR viewpoint-where we analyse individual sub-layers characteristics. The vibrational Density of States (VDOS) revealed that the first solvation sub-shell indicates a confined character therein. For layers of increasing distance from the surface, the adoption of greater bulk-like spectral behaviour was evident, suggesting that vibrational harmonisation to bulk occurs within 6-7 Å of the surface.

Flexible cellulose nanocrystal-based bionanocomposite film as a smart photonic material responsive to humidity

A flexible bionanocomposite film with a visible structural color was developed by co-assembling cellulose nanocrystals with glycerol, glucose, and poly(vinyl alcohol), and its application as a photonic humidity-responsive material was investigated. This chiral nematic film exhibited an indigo, cyan, olive green, orange, pink, and transparent color when exposed to relative humidity of 33%, 75%, 85%, 89%, 96%, and 100%, respectively. The color change was caused by reversible change in chiral nematic pitch due to hydration and dehydration. The nanocomposite displayed a stable structural color after alternatively conditioned at 33% and 100% relative humidity for ten cycles. Notably, material cost for a piece of such a smart film with an area of 28 cm² is less than $0.1 USD. This flexible, uniform bionanocomposite film has great potential to be used as a smart photonic material responsive to humidity.

Fourier Transform Infrared (FTIR) Spectroscopic Analyses of Microbiological Samples and Biogenic Selenium Nanoparticles of Microbial Origin: Sample Preparation Effects

To demonstrate the importance of sample preparation used in Fourier transform infrared (FTIR) spectroscopy of microbiological materials, bacterial biomass samples with and without grinding and after different drying periods (1.5-23 h at 45 °C), as well as biogenic selenium nanoparticles (SeNPs; without washing and after one to three washing steps) were comparatively studied by transmission FTIR spectroscopy. For preparing bacterial biomass samples, Azospirillum brasilense Sp7 and A. baldaniorum Sp245 (earlier known as A. brasilense Sp245) were used. The SeNPs were obtained using A. brasilense Sp7 incubated with selenite. Grinding of the biomass samples was shown to result in slight downshifting of the bands related to cellular poly-3-hydroxybutyrate (PHB) present in the samples in small amounts (under ~10%), reflecting its partial crystallisation. Drying for 23 h was shown to give more reproducible FTIR spectra of bacterial samples. SeNPs were shown to contain capping layers of proteins, polysaccharides and lipids. The as-prepared SeNPs contained significant amounts of carboxylated components in their bioorganic capping, which appeared to be weakly bound and were largely removed after washing. Spectroscopic characteristics and changes induced by various sample preparation steps are discussed with regard to optimising sample treatment procedures for FTIR spectroscopic analyses of microbiological specimens.