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Two new biflavanones ( 1 and 2 ), three new bichalconoids ( 3 – 5 ), and 11 known flavonoid analogues ( 6 – 16 ) were isolated from the stem bark extract (CH 3 OH–CH 2 Cl 2 , 7:3, v/v) of Ochna holstii . The structures of the isolated metabolites were elucidated by NMR spectroscopic and mass spectrometric analyses. The crude extract and the isolated metabolites were evaluated for antibacterial activity against Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) as well as for cytotoxicity against the MCF-7 human breast cancer cell line. The crude extract and holstiinone A ( 1 ) exhibited moderate antibacterial activity against B. subtilis with MIC values of 9.1 μg/mL and 14 μM, respectively. The crude extract and lophirone F ( 14 ) showed cytotoxicity against MCF-7 with EC 50 values of 11 μg/mL and 24 μM, respectively. The other isolated metabolites showed no significant antibacterial activities (MIC > 250 μM) and cytotoxicities (EC 50 ≥ 350 μM).

Antibiotic resistance among bacteria is a growing global challenge. A major reason for this is the limited progress in developing new classes of antibiotics active against Gram-negative bacteria. Here, we investigate the antibacterial activity of a dicationic bisguanidine-arylfuran, originally developed as an antitrypanosomal agent, and new derivatives thereof. The compounds showed good activity (EC50 2–20 µM) against antibiotic-resistant isolates of the Gram-negative members of the ESKAPE group (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) and Escherichia coli with different antibiotic susceptibility patterns, including ESBL isolates. Cytotoxicity was moderate, and several of the new derivatives were less cytotoxic than the lead molecule, offering better selectivity indices (40–80 for several ESKAPE isolates). The molecular mechanism for the antibacterial activity of these molecules is unknown, but sensitivity profiling against human ESKAPE isolates and E. coli collections with known susceptibility patterns against established antibiotics indicates that it is distinct from lactam and quinolone antibiotics.

Five new cyclohexene derivatives, dipandensin A and B ( 1 and 2 ) and pandensenols A–C ( 3 – 5 ), and 16 known secondary metabolites ( 6 – 21 ) were isolated from the methanol-soluble extracts of the stem and root barks of Uvaria pandensis . The structures were characterized by NMR spectroscopic and mass spectrometric analyses, and that of 6-methoxyzeylenol ( 6 ) was further confirmed by single-crystal X-ray crystallography, which also established its absolute configuration. The isolated metabolites were evaluated for antibacterial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus epidermidis and the Gram-negative bacteria Enterococcus raffinosus , Escherichia coli , Paraburkholderia caledonica , Pectobacterium carotovorum , and Pseudomonas putida , as well as for cytotoxicity against the MCF-7 human breast cancer cell line. A mixture of uvaretin ( 20 ) and isouvaretin ( 21 ) exhibited significant antibacterial activity against B. subtilis (EC 50 8.7 μM) and S. epidermidis (IC 50 7.9 μM). (8′α,9′β-Dihydroxy)-3-farnesylindole ( 12 ) showed strong inhibitory activity (EC 50 9.8 μM) against B. subtilis , comparable to the clinical reference ampicillin (EC 50 17.9 μM). None of the compounds showed relevant cytotoxicity against the MCF-7 human breast cancer cell line.

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The purpose of this research is to determine the intensity of biofilm formation, adhesion and motility of bacteria depending on different types of children's urinary tract infections. Materials and methods: the paper contains the research of adhesion, motility and biofilm formation properties of 44 clinical isolates of bacteria from children with lower urinary tract infections, acute and chronic pyelonephritis. The ability of bacteria to form biofilms was tested using the method of microtiter plates. The motility of the microorganisms was tested using standard methods. The ability of bacteria to adhere was investigated according to Brilis, through the use of formalinized erythrocytes. Results: differences were found in the ability to form biofilm between strains of bacteria that cause infections of the lower urinary tract (optical density 0.40 ± 0.06) and chronic pyelonephritis (optical density 0.48 ±0.07) (p<0.05). Furthermore, a correlation was established between adhesion and biofilm formation abilities of bacteria (r = 0.529 (p<0.01)). It was detected that increased motility ability of the bacteria reduces the force applied by this strain to form biofilm. Conclusions: bacteria isolated from children with acute and chronic pyelonephritis showed higher ability to adhere and form biofilm than the bacteria isolated from children with lower urinary tract infection. High ability to form biofilm and adhere of the isolated bacteria can be considered an adverse predictive factor in the course of urinary tract infection.

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