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Brown seaweeds are known for their bioactive compounds, particularly sulfated polysaccharides such as fucoidans, which have demonstrated antiviral properties. However, limited studies have focused on the antiviral potential of fucoidans extracted from Mediterranean brown seaweeds. In this study, two brown seaweeds Padina pavonica and Dictyopteris membranacea (Fuc-Pad and Fuc-Dic, respectively) were collected from monastir coasts, Tunisia, and a specific extraction protocol was employed to obtain fucoidans. The main objective of this study was to evaluate their antiviral activity against Herpes simplex virus type 2 (HSV-2) and coxsackievirus B3 (CVB-3). Fuc-Pad and Fuc-Dic exhibited potent antiviral activity with high selectivity indexes (>158 780 and 3125 for Fuc-Pad and 6101 and 84 for Fuc-Dic against HSV-2 and CVB-3, respectively). On the other hand, the two brown algae demonstrated different mechanisms of antiviral action according to virus type since they inhibited HSV-2 during the adsorption and penetration stages likely through interaction with cellular receptors that block viral binding while directly inhibiting CVB-3 by blocking specific viral ligands, preventing their attachment to host cell receptors. This antiviral activity seems to be associated with the high degree of sulfating of the fucoidans. These results may suggest the possibility of developing new antiviral drugs. [ABSTRACT FROM AUTHOR]

Asphodelus tenuifolius Cav. (A. tenuifolius) is a medicinal plant with a long history of traditional use to treat ailments. In this study, total phenolic and flavonoid content evaluation using LC-ESI/MS analysis and various biological activities (antioxidant, antibacterial, antifungal, antiviral and cytotoxicity) of organic extracts from the aerial parts of A. tenuifolius were analyzed. ADME tools were used to predict the potential of the identified compounds from the most potent extract as specific drugs. As shown, LC-ESI/MS results of chloroformic extract allowed the tentative identification of 12 compounds. Chloroformic extract was rich in polyphenols and flavonoids and exhibited the highest antioxidant activity given by DPPH (IC50 = 25 µg/mL) as compared to the BHT standard (11.5 µg/mL) and β-carotene bleaching assays (IC50 = 95.692 µg/mL). Antibacterial activity results showed that chloroformic extract has a highest activity against Gram-positive and -negative bacteria, especially against Salmonella Typhimurium DT104 (IZ = 19.3 mm, MIC = 18.75 mg/mL, MBC = 37.5 mg/mL). The MBC/MIC ratio was evaluated to interpret the activity that was bacteriostatic rather than bactericidal. Conversely, weaker antifungal activity was registered, and no antiviral activity was observed for all extracts against Herpes Simplex Virus type 2 and Coxsakievirus B-3 viruses. Cytotoxic activity on VERO cell line results revealed that butanol extract was not toxic, with CC50 value of 1430 µg/mL, while chloroformic extract showed moderate cytotoxicity. Additionally, in silico studies performed proved promising pharmacokinetic and drug-likeness properties of the main compounds from the chloroformic extract. Taken together, this work highlights the potent bioactivity and acceptable drug-likeness of this plant, which supports its further preclinical development.

Objective: Echovirus 11 is one of the most frequently isolated enterovirus serotypes, causing a wide range of clinical diseases. We studied the genetic diversity in the 3′ end of the VP1 gene of strains from different geographical origin in the world. Methods: The sequences in the 3′ end of the VP1 of 11 Tunisian isolates were determined and aligned with the published sequences to establish a phylogenetic profile. Results: The grouping of the sequences was similar to what was previously reported by analyzing the whole VP1 gene with 4 genogroups, designated A–D, and 5 lineages in genogroup D. All Tunisian strains belonged to genogroup D, together with other sequences mainly from the USA and Europe. Contrary to the sequences from the USA isolated during the last 3 decades, which mostly belonged to the D4 lineage, those from Tunisia belonged to different lineages within genogroup D according to their isolation date: isolates from the early 1990s belonged to D3, those of the mid 1990s to D4 and the most recent ones to D5. Conclusion: Our findings further widen the interest of partial sequencing in the VP1 to study the molecular epidemiology of echovirus 11 and indicate that the genetic evolution of circulating strains may differ from one country to another according to the region’s epidemiological specificities. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

An easy and efficient approach for the synthesis of highly regioselective functionalized dihydronaphthalen-1(2 H )-one family of α-tetralones from functionalized tetralone precursors which derived from Morita-Baylis-Hillman (MBH) adducts as starting substrates has been developed. The target dihydronaphthalen-1(2 H )-ones are obtained through the oxidation of tetrahydronaphthalenes (THN) using DDQ as the oxidizing agent, conducted in aqueous acetic acid at reflux conditions. The yields obtained ranged from 90 to 98%. The resulting dihydronaphthalen-1(2 H )-ones were evaluated for their in vitro antibacterial activity against nine Gram-positive and six Gram-negative strains. Additionally, their antifungal properties were assessed against three fungal pathogens by using the microdilution method and Biolog Phenotype Microarrays technology. Remarkably, the synthesized dihydronaphthalen-1(2 H )-ones exhibited good antibacterial activity when compared to reference drugs such as vancomycin and ampicillin. Similarly, their antifungal activity is comparable to the effectiveness of the reference drugs cycloheximide and fluconazole., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)