Antifungal activity of novel azetidine tethered chitosan synthesized via multicomponent reaction approach.

The increasing incidences of fungal infections among Covid-19 infected patients is a global public concern and urgently demands novel antifungals. Biopolymers like chitosan hold unique structural properties and thus can be utilized in the synthesis of biologically important scaffolds. To address the current scenario, the author's synthesized novel chitosan-azetidine derivative by adopting one-pot multicomponent reaction approach. The influence of chemical modification on the structural characteristics was investigated by means of spectroscopic techniques viz. FT-IR and 1HNMR and elemental analysis. Additionally, the authors investigated the antifungal potential of chitosan-azetidine derivative against Aspergillus fumigatus 3007 and the results indicated higher antifungal effect with an antifungal inhibitory index of 26.19%. The SEM and confocal microscopy images also reflected a significant inhibitory effect on the morphology of fungal mycelia, thus reflecting the potential of synthesized chitosan-azetidine derivativeas a potential antifungal agent.

Polysaccharides and lipoproteins as reactants for the synthesis of pharmaceutically important scaffolds: A review.

The growing number of diseases in the past decade has once again highlighted the need for extensive research on the development of novel drugs. There has been a major expansion in the number of people suffering from malignant diseases and types of life-threatening microbial infections. The high mortality rates caused by such infections, their associated toxicity, and a growing number of microbes with acquired resistance necessitate the need to further explore and develop the synthesis of pharmaceutically important scaffolds. Chemical entities derived from biological macromolecules like carbohydrates and lipids have been explored and observed to be effective agents in the treatment of microbial infections and diseases. These biological macromolecules offer a variety of chemical properties that have been exploited for the synthesis of pharmaceutically relevant scaffolds. All biological macromolecules are long chains of similar atomic groups which are connected by covalent bonds. By altering the attached groups, the physical and chemical properties can be altered and molded as per the clinical applications and needs, this ring them potential candidates for drug synthesis. The present review establishes the role and significance of biological macromolecules by articulating various reactions and pathways reported in the literature.

Carbohydrate hitched imidazoles as agents for the disruption of fungal cell membrane.

The fungal diseases represent an increasing global health burden and have transformed from a rare curiosity to the leading cause of human mortality. The present manuscript reports the antifungal potential of two novel compounds possessing a carbohydrate and an imidazole moiety. Antifungal susceptibility test determined the growth inhibition potential of the synthesized compounds against Aspergillus niger 9689 and it was observed that compounds D and E gave an antifungal inhibitory index of 66.66 and 56.67% respectively. Further, ultra-structure analysis of the treated fungal mycelia through scanning electron microscope (SEM) and confocal microscopy indicated significant membrane permeability and disintegration of fungal cell membrane, thus highlighting the probable role of the synthesized compounds as inhibitors of fungal lanosterol 14α-demethylase. In silico studies corroborated with the in-vitro results, as the synthesized compounds interacted with the critical amino acids present at the active site of the fungal enzyme (lanosterol 14α-demethylase).

Effect of synthesis temperature and doping level on conductivity and structure of poly(3-methyl thiophene).

Poly(3-methyl thiophene) was synthesized by oxidative chemical polymerization technique using ferric chloride as the dopant in an inert atmosphere. Samples of different doping levels were prepared and analyzed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, and direct current (DC) conductivity measurement at room temperature (300 K). Synthesis of the polymer was confirmed by FTIR studies. FTIR spectra showed a shift in the heterocyclic bands in the region of 700-1200 cm(-1) with a decrease in synthesis temperature. It was evident from the scanning electron micrographs that the surface structure of the polymer became denser with an increase in doping level. The measured DC conductivity increased initially up to the doping level of 0.8 M and then this increase tended to slow down. Samples having a doping level of 0.4 M were synthesized at 300, 280, and 270 K while maintaining the other synthesis parameters. The conductivity and yield were found to increase as the temperature of the polymerization decreased.

Direct current conductivity studies on poly(3-methyl thiophene).

The direct current (DC) conductivity of poly(3-methyl thiophene) was measured in the temperature range of 77-300 K. The observed DC conductivity data were analyzed in the light of Mott's variable range hopping model. Different Mott's parameters such as characteristic temperature (T0), average hopping distance (R), average hopping energy (W), and density of states at the Fermi level (N [E(F)]) were evaluated. By taking the inverse of the coefficient of exponential decay of the localized states involved in the hopping process as 0.5 nm, a realistic value of density of states at the Fermi level (N [E(F)]) was obtained that agrees well with the values reported earlier for other conjugated polymers.