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

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.

Antifungal activity and mechanism of electron beam irradiation against Rhizopus oryzae

Electron beam irradiation is a physical fungicidal technique that has emerged as a potential application in China. However, its antifungal activity and mechanism against Rhizopus oryzae have not been reported. Thus, this study aimed to investigate the antifungal activity and mechanism of electron beam irradiation of R. oryzae. The antifungal activity analysis showed that the D₁₀ value and complete elimination dose of R. oryzae irradiated by electron beam were 1.73 kGy and 8.08 kGy, respectively. Electron beam irradiation has a strong inhibitory effect on the filamentous biomass of R. oryzae. To reveal the antifungal mechanism of electron beam against R. oryzae, this study analyzed the dynamic changes in the cell wall, cell membrane, and oxidative stress induced by different irradiation doses. The results showed that electron beam irradiation destroyed the cell wall structure of R. oryzae, increasing chitinase activity and decreasing chitin content. Cell membrane integrity is disrupted, increasing relative conductivity, decreasing pH values, and decreasing soluble protein content. Electron beam irradiation causes oxidative stress in cells, increasing H₂O₂ content, decreasing antisuperoxide anion activity, decreasing DPPH free radical scavenging activity, and inhibiting defense enzyme (CAT and SOD) activity. This phenomenon indicates that electron beams can cause structural damage to and metabolic dysfunction of cells and disorders of redox homeostasis, which may be the main cause of growth inhibition and cell death in R. oryzae.

Exploration of novel TOSMIC tethered imidazo[1,2-a]pyridine compounds for the development of potential antifungal drug candidate

New candidates of imidazo[1,2-a]pyridine were designed by combining 2-amino pyridine, TOSMIC and various assorted aldehydes to explore their antioxidant and antifungal potential. The design of these derivatives was based on utilizing the antifungal potential of azoles and TOSMIC moiety. These derivatives were synthesized by adopting multi-component reaction methodology, as it serves as a rapid and efficient tool to target structurally diverse heterocyclic compounds in quantitative yield. The resulting imidazo[1,2-a]pyridine derivatives were structurally verified by ¹ HNMR, ¹³ CNMR, HRMS, and HPLC. The compounds were analyzed for their antioxidant and fluorescent properties and it was observed that compound 15 depicted highest potential. The compounds were evaluated for their antifungal potential to highlight their medical application in the area of Invasive Fungal Infections (IFI). Compound 12 gave the highest antifungal inhibition against Aspergillus fumigatus 3007 and Candida albicans 3018. To elucidate the antifungal mechanism, confocal images of treated fungi were analyzed, which depicted porous nature of fungal membrane. Estimation of fungal membrane sterols by UPLC indicated decrease in ergosterol component of fungal membrane. In silico studies further corroborated with the in vitro results as docking studies depicted interaction of synthesized heterocyclic compounds with amino acids present in the active site of target enzyme (lanosterol 14 alpha demethylase). Absorption, distribution, metabolism, and excretion (ADME) analysis was indicative of drug-likeliness of the synthesized compounds.

A Review of Characteristics, Properties, Application of Nanocarriers and Analytical Methods of Luliconazole

Luliconazole is an imidazole agent, used for the treatment of fungi infection, especially dermatophytes. The mechanism of action of the drug consisting in inhibits sterol 14α-demethylase which interferes with ergosterol biosynthesis. Due to low aqueous solubility and highly lipophilic, there is a need to develop drug delivery systems (nanocarriers) capable to increase the solubility, permeability, and skin retention of luliconazole, and promote a better therapeutic effect. In this context, this review presents characteristics, properties, nanocarriers, and analytical methods used for luliconazole. From the analyzed studies, the majority reports the use of RP-HPLC techniques for luliconazole determination, but also are cited spectrophotometric UV methods. The luliconazole has been qualitatively and quantitatively analyzed in different matrices, such as raw material and pharmaceutical formulations, however, in this review, only one study was found with the luliconazole quantification biological matrix, demonstrating the lack of studies related to the quantification of the drug in biological matrices. The drug quantification in different matrices by analytical methods is of great importance since they assist in the control of the quality, efficacy, and safety of the medicine.