Carmellina Daniela Bădiceanu

Nosocomial fungal infections caused by Candida auris pose a threat to public health due to their increased resistance to common antifungal drugs. Four thiourea derivatives of 2-thiophenecarboxylic acid were evaluated for their antifungal and antioxidant activity. The antifungal activity of the compounds was tested against strains of C. auris isolated from a hospital in Romania. With a notable inhibitory effect on C. auris biofilm growth and microbial adherence, the ortho-methylated derivative (SB2) showed the highest antifungal activity. Furthermore, emphasizing the impact of structural factors on the electron-donating capacity of these compounds, antioxidant activity assays (DPPH, FRAP, TEAC and CUPRAC) identified the SB2 compound as having the highest antihemolytic and antioxidant effects. The low cytotoxicity validated by hemocompatibility assays makes these compounds options for antifungal treatment. The results show that antifungal and antioxidant action is greatly influenced by structural modifications, especially the position of the methyl group on the aromatic ring. The possible clinical uses of these molecules as drugs for the treatment of multidrug-resistant C. auris infections needs further investigation.

Novel phthalimide derivatives, namely N-(1,3-dioxoisoindolin-2-yl)-2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetamide (1a) and N-(1,3-dioxoisoindolin-2-yl)thiophene-2-carboxamide (1b), and hexahydrophthalimide derivative N-(1,3-dioxohexahydro-1H-isoindol-2(3H)-yl)-2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetamide (2), have been synthesized. The phthalimide derivatives were synthesized from phthalic anhydride and 2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide or thiophene-2-carbohydrazide, and the hexahydrophthalimide derivative has been synthesized from hexahydrophthalic anhydride and 2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide. The chemical structures of the compounds are elucidated by Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectra. The new in vitro antioxidant activities of the obtained substances were evaluated using the DPPH method. All tested compounds showed antioxidative activity, the most active compound being 1b. Bioinformatics tools were used for the prediction of pharmacokinetics and pharmacodynamics profiles. Our results showedthat all compounds have a suitable intestinal absorption rate, good BBB and CNS permeabilities and have as molecular targets MAO B, COX-2 and NF-KB, important for antioxidant activities.

Ziziphus jujuba Mill. (jujube) is a well-known medicinal plant with pronounced wound healing properties. The present study aimed to establish the chemical composition of the lyophilized ethanolic extract from Romanian Ziziphus jujuba leaves and to evaluate the healing and anti-inflammatory properties of a newly developed lipophilic ointment containing 10% dried jujube leaves extract. The ultra-High-Performance Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry method was used, and 47 compounds were detected, among them the novel epicatechin and caffeic acid. The extract contains significant amounts of rutin (29.836 mg/g), quercetin (15.180 mg/g) and chlorogenic acid (350.96 µg/g). The lipophilic ointment has a slightly tolerable pH, between 5.41–5.42, and proved to be non-toxic in acute dermal irritation tests on New Zealand albino rabbits and after repeated administration on Wistar rats. The ointment also has a healing activity comparable to Cicatrizin (a pharmaceutical marketed product) on Wistar rats and a moderate anti-inflammatory action compared to the control group, but statistically insignificant compared to indomethacin in the rat-induced inflammation test by intraplantar administration of kaolin. The healing and anti-inflammatory properties of the tested ointment are due to phenolic acids and flavonoids content, less because of minor components as apocynin, scopoletin, and isofraxidin.

Graphite was oxidized to graphene oxide and activated by thionyl chloride, for further covalently linking three hydrazides with potential biological activity. The obtained materials were characterized by scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared and Raman spectroscopies. The presence of various functional groups specific to graphene oxide (GO) functionalized with different hydrazides was confirmed by spectral data. The ratio between D- and G-bands, observed in Raman spectra, allowed for an evaluation of the disorder degree and the mean crystallite size of the samples. The micrographs highlighted that the samples lead to the occurrence of disorders, probably caused by the sp³ carbons, the formation of oxygen-containing functional groups in the basal planes, and by various structural defects. The new graphene oxide–hydrazide derivatives were tested for their antimicrobial and cytotoxicity activity. Their antimicrobial activity against planktonic and biofilm-embedded cells was inferior to that of free hydrazides, except for GO-3 against planktonic Escherichia coli and GO-2 against Pseudomonas aeruginosa biofilm, demonstrating that further optimization is needed to be able to exploit the huge potential of GO for developing potent antimicrobials.