Antifungal activity of dialdehyde chitosan against Aspergillus brasiliensis and Candida albicans

Synergistic Antifungal Activity of Dialdehyde Chitosan Loaded with Copper Metal‐Organic Framework (Cu‐MOF)

“…A controlled reaction condition of temperature and the molar concentration between potassium periodate and the vicinal diols in Cs leading to cleavage of the glycosidic bonds results in the formation of C=O. [22] There was another broadband at 1556 cm À 1 attributed to NÀ H (amide II) bending vibration and CÀ OÀ C glycosidic linkage vibration appearing at 1012 cm À 1 . The OCs spectra also displayed peaks at 3446 cm À 1 , and 3261 cm À 1 related to the stretching vibration of NH and OH respectively.…”

“…[50] From the previous study, the crystallite size and the degree of crystallinity for OCs were calculated and found to be 12.8 nm and 21.9 % respectively. [22] The decrease in the crystallite sizes of Cu-MOF-OCs after modification was an indication that the Cu 2 + ions were securely anchored on both the TP and OCs networks by À NH 2 , À OH, and C=O functional groups resulting in the formation of small crystals of Cu-MOF-OCs due to their orientation to a limited space. [23] The existence of Cu-MOF-OCs as nanoparticles are significant antifungal property in imparting the required toxicity on the target fungi by overcoming the cellular barriers of the cell membrane, traversing across it, and subsequently releasing the copper ions hence eliciting cell oxidative stress.…”

“…As detailed in our previously published work, [22] chitosan (Cs) was extracted from black soldier flies (BSF) exoskeleton by demineralization, deproteinization, decolorization, and deacetylation [26] and finally oxidized using potassium periodate. [27]…”

“…The samples were irradiated with a monochromatic CuKα radiation of 0.1542 nm, and the diffractograms acquired between 2θ values of 5°-90°at 0.05°intervals with a measurement time of 1 s per 2θ intervals. [22] The average crystalline size of the Cs and dialdehyde Cs was calculated using Debye-Scherrer equation (1).…”

“…Cs contains primary amine and hydroxyl functional groups and notably, periodate oxidation of Cs introduced carbonyl groups (C=O) in its structure which showed improved antifungal activities against Aspergillus spp and Candida spp. [22] In this study, we report for the first time the synthesis of Cu-MOF-OCs by loading Cu-MOF to dialdehyde Cs (OCs). Firstly, Cs were extracted from BSF and oxidized using potassium periodate to obtain dialdehyde Cs (OCs) and Cu-MOF was synthesized using copper sulfate and terephthalic acid.…”