Synthesis of novel azabicyclo derivatives containing a thiazole moiety and their biological activity against pine-wood nematodes

Synthesis and anti-proliferative effect of novel 4-Aryl-1, 3-Thiazole-TPP conjugates via mitochondrial uncoupling process

With the advent of mitochondrial targeting moiety such as triphenlyphosphonium cation (TPP+), targeting mitochondria in cancer cells has become a promising strategy for combating tumors. Herein, a series of novel 4-aryl-1,3-thiazole derivatives linked to TPP+ moiety were designed and synthesized. The cytotoxicity against a panel of four cancer cell lines was evaluated by CCK-8 assay. Most of these compounds exhibited moderate to good inhibitory activity over HeLa, PC-3 and HCT-15 cells while MCF-7 cells were less sensitive to most compounds. Among them, compound 12a exhibited a significant anti-proliferative activity against HeLa cells, and prompted for further investigation. Specifically, 12a decreased mitochondrial membrane potential and enhanced levels of reactive oxygen species (ROS). The flow cytometry analysis revealed that compound 12a could induce apoptosis and cell cycle arrest at G0/G1 phase in HeLa cells. In addition, mitochondrial bioenergetics assay revealed that 12a displayed mild mitochondrial uncoupling effect. Taken together, these findings suggest the therapeutic potential of compound 12a as an antitumor agent targeting mitochondria.

Discovery of Quaternized Pyridine-Thiazole-Pleuromutilin Derivatives with Broad-Spectrum Antibacterial and Potent Anti-MRSA Activity

The quaternization of compounds has emerged as a promising molecular design strategy for the development of antibiotics. Herein, we report the design, synthesis, antibacterial activities, and structure-activity relationships of a series of novel pleuromutilin derivatives containing a quaternary amine C-14 side chain. Most of these derivatives exhibited broad-spectrum antibacterial activity against the tested bacteria. 10b was the most effective antibacterial agent that displayed excellent antibacterial activity against five clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates, remarkable antimycoplasma activity, rapid bactericidal effects, and a strong ability to damage bacterial biofilms. Further mechanistic studies indicated that 10b destroyed bacterial cell membranes to exert its antibacterial effects. Moreover, 10b exhibited high survival protection and potent in vivo antibacterial efficacy (ED₅₀ = 4.94 mg/kg) in a mouse model of systemic MRSA infection. These findings suggest that 10b is a promising candidate for the treatment of multi-drug-resistant infectious diseases, especially MRSA infections.

Biological pesticides and solvents with low toxicity reduce motility and activity of Bursaphelenchus xylophilus

Pine wilt disease (PWD), caused by the pine wood nematode, Bursaphelenchus xylophilus, is an international quarantine forest disease that damages pine forests over extensive areas and causes massive economic losses. To provide valuable guidelines on screening pesticides against B. xylophilus and the selection of common solvents, we investigated the effects of different concentrations of emamectin benzoate, matrine and four solvents (methanol, ethanol, acetone and dimethyl sulfoxide) on the mortality and locomotor behaviour of B. xylophilus. Emamectin abamectin has nematicidal activity and mitigates locomotor activity of B. xylophilus at a low concentration. The LC50 of emamectin benzoate was 0.0354 mg l−1 at 72 h. Bursaphelenchus xylophilus mortality following exposure to matrine was low; however, nematode locomotor activity decreased by 62.5% following exposure to 500 mg l−1 matrine for 8 h. Additionally, B. xylophilus locomotor activity decreased significantly following exposure to 5 and 10% methanol, ethanol, acetone and dimethyl sulfoxide (DMSO) when compared with that of the water control. Emamectin benzoate and matrine, and high concentrations of four solvents (methanol, ethanol, acetone, and DMSO) inhibit B. xylophilus movement, which, in turn, could affect nematode infectivity. Moreover, low concentrations of non-lethal doses of emamectin benzoate should be considered for application in the control of nematodes, with matrine being an environmentally friendly and potentially nematicidal agent.

Chemical Nematicides: Recent Research Progress and Outlook

Plant-parasitic nematodes have caused huge economic losses to agriculture worldwide and seriously threaten the sustainable development of modern agriculture. Chemical nematicides are still the most effective means to manage nematodes. However, the long-term use of organophosphorus and carbamate nematicides has led to a lack of field control efficacy and increased nematode resistance. To meet the huge market demand and slow the growth of resistance, new nematicides are needed to enter the market. The rational design and synthesis of new chemical scaffolds to screen for new nematicides is still a difficult task. We reviewed the latest research progress of nematicidal compounds in the past decade, discussed the structure-activity relationship and mechanism of action, and recommended some nematicidal active fragments. It is hoped that this review can update the recent progress on nematicide discoveries and provide new ideas for the design and mechanism of action studies of nematicides.