Search

The leaves of Ilex paraguariensis (known as Yerba mate), used as a popular beverage, are a very well-recognized plant material with various biological activities, including analeptic (because of caffeine), anti-obesity (phenolics, saponins), antimicrobial, and antiviral (phenolics, saponins). Here, the chemical compositions of the leaves of two European Ilex species (× meserveae and aquifolium) with three varieties each were investigated. The terpenoid, saponin, and polyphenolic fractions were submitted for LC-MS or GC-MS analysis against a standard Mate leaf. In addition, the aroma profiles of all the species were analysed using HS-SPME-Arrow prior to GC-MS analysis. All fractions were subjected to antiviral and cytotoxic assays. We found 86 compounds in all accessions, with limonene, linalool, and p-cymene being predominant. There were minor similarities between the volatile compositions of the European and South American species. We found ursolic and oleanolic acid to be the main compounds in the terpenoid fraction. Mono-caffeoylquinic acids and di-caffeoylquinic acids were the main constituents of the polar fractions. About 180 compounds from the saponin group were tentatively identified, of which 9 and 3 were selected as distinctive markers for I. meserveae and I. aquifolium, respectively. Based on chemical screening, I. aquifolium Silver Queen was chosen as the source of terpenoid and saponin fractions and polyphenol extracts. The most substantial inhibition of cancer cell growth was observed with saponin in the case of the MCF7 (human breast cancer) cell line, while for LoVo and L929 cell lines (human colorectal cancer and reference mouse fibroblasts), it was slightly weaker. These results should be analysed further as a promising chemoprevention of colorectal and gastrointestinal cancers. Saponin and polyphenolic extracts exhibited similar activities against HSV-1 and HAdV-5, with 4-log reduction in virus titres. This study focuses our attention on a field of potential antiviral formulations derived from European holly. [ABSTRACT FROM AUTHOR]

Triggered by the urgent need to tackle the global crisis of multidrug-resistant bacterial infections, in this work, we present a way to overcome chloramphenicol resistance by introducing modifications based on the glycosylation of its hydroxyl groups. The synthesized derivatives demonstrate complete resistance to the action of recombinant chloramphenicol acetyltransferase (CAT) from Escherichia coli and efficacy against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli ESBL, and Pseudomonas aeruginosa ATCC 27853. Glycosylation gives chloramphenicol an additional advantage - the stable glycosidic form is less toxic to human dermal fibroblasts and has significantly better water solubility than non-glycosylated chloramphenicol. Using a specific glycosidase, chloramphenicol can be almost immediately released from the stable prodrug at the site of polybacterial infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)