Synthesis and biological evaluation of ruthenium complexes containing phenylseleny against Gram-positive bacterial infection by damage membrane integrity and avoid drug-resistance.

Compounds modified with selenium atom as potential antibacterial agents have been exploited to combat the nondrug-resistant bacterial infection. In this study, we designed and synthesized four ruthenium complexes retouching of selenium-ether. Fortunately, those four ruthenium complexes shown excellent antibacterial bioactive (MIC: 1.56-6.25 µg/mL) against Staphylococcus aureus (S. aureus), and the most active complex Ru(II)-4 could kill S. aureus by targeting the membrane integrity and avoid the bacteria to evolve drug resistance. Moreover, Ru(II)-4 was found to significantly inhibit the formation of biofilms and biofilm eradicate capacity. In toxicity experiments, Ru(II)-4 exhibited poor hemolysis and low mammalian toxicity. To illustrate the antibacterial mechanism: we conducted scanning electron microscope (SEM), fluorescent staining, membrane rupture and DNA leakage assays. Those results demonstrated that Ru(II)-4 could destroy the integrity of bacterial cell membrane. Furthermore, both G. mellonella wax worms infection model and mouse skin infection model were established to evaluate the antibacterial activity of Ru(II)-4 in vivo, the results indicated that Ru(II)-4 was a potential candidate for combating S. aureus infections, and almost non-toxic to mouse tissue. Thus, all the results indicated that introducing selenium-atom into ruthenium compounds were a promising strategy for developing interesting antibacterial agents.

Anticancer activities of proanthocyanidins from the plant Urceola huaitingii and their synergistic effects in combination with chemotherapeutics.

Phytochemical investigation of the stem of Urceola huaitingii resulted in the isolation of nine proanthocyanidins (1-9), including a new compound (9). Their chemical structures were determined by UV, (HR) ESI-MS, 1D-, 2D-NMR, and CD spectra in combination with chemical derivatization. Determination of the absolute configuration of proanthocyanidins were discussed, which suggested that positive Δε values at 245nm can be applied to determine the absolute configuration of them. In addition, anticancer activities of proanthocyanidins (1-9) and their synergistic anticancer effects in combination with chemotherapeutics were evaluated. The results showed that some proanthocyanidins, especially compound 7 possessing two doubly interflavonoid linkages, exhibited significant synergistic anticancer effects with some chemotherapeutics in multiple cancer cell lines.

Galiellalactone analogs and their possible precursors from Sarcosomataceae.

Galiellalactone analogs (1-4) (including two new compounds), together with their possible precursors (5-9, named pregaliellalactone B-F), were obtained from the solid cultures of an endophytic fungus Sarcosomataceae NO.45-1-8-1. Their chemical structures were elucidated by analyses of HR ESI-TOF MS, 1D-, 2D-NMR, CD spectra and single crystal X-ray diffraction methods. Compounds 5-9, the possible precursors of galiellalactone analogs, were found to exist as enantiomers for the first time. The cytotoxicity of these compounds against six tumor cell lines was examined and preliminary structure-activity relationship (SAR) was also discussed.