John B. Bremner

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Allelopathy has been suggested as a mechanism promoting the monoculture formation of some invasive exotic plants. Previous studies have shown that hydrophobic extracts of the roots and soil of exotic bitou bush (Chrysanthemoides monilifera spp. rotundata (DC.) T. Norl.) inhibited the seedling growth of five Australian native plants, including the dominant(More)
Many marine invertebrates deposit benthic egg masses that are potentially vulnerable to microbial infection. To help counter this threat these species may have evolved some form of chemical protection for their encapsulated embryos. In this study the egg masses from 7 marine mollusks were tested for antibacterial activity against 4 marine pathogens:(More)
Chemical interference is increasingly suggested as a mechanism facilitating exotic plant invasion and plant community composition. In order to explore this further, we employed a comprehensive extract-bioassay technique that facilitated detection and demarcation of phytotoxicity, direct allelopathy and indirect allelopathy of bitou bush (Chrysanthemoides(More)
Hybrid antimicrobials containing an antibacterial linked to a multidrug resistance (MDR) pump inhibitor make up a promising new class of agents for countering efflux-mediated bacterial drug resistance. This study explores the effects of varying the relative orientation of the antibacterial and efflux pump inhibitor components in three isomeric hybrids(More)
Alpha1 adrenoceptors have three subtypes and drugs interacting selectively with these subtypes could be useful in the treatment of a variety of diseases. In order to gain an insight into the structural principles governing subtype selectivity, ligand based drug design (pharmacophore development) methods have been used to design a novel 1,2,3-thiadiazole(More)
Changes to ecosystem abiotic parameters are regarded as possible mechanisms facilitating plant invasion and community composition shifts. This study compared the hydrophobic chemical signatures of soil from exotic bitou bush (Chrysanthemoides monilifera spp. rotundata) invaded, indigenous acacia (Acacia longifolia var. sophorae) dominated and bare sand(More)
In order to develop structure-activity relationships and to provide access to antibacterial agents for dual action studies, a variety of aryl group-substituted 2-aryl-5-nitro-1H-indoles were synthesized and the activity of the compounds assessed as inhibitors of the NorA multidrug resistance pump in the bacterium Staphylococcus aureus. The NorA protein from(More)
The alkaloidal components of the Bhutanese medicinal plant Corydalis calliantha Long, which is used for the treatment of malaria, have been assessed. Four known alkaloids, protopine (1), scoulerine (2), cheilanthifoline (3) and stylopine (4) are reported from this plant for the first time. The protopine alkaloid, protopine, and the tetrahydroprotoberine(More)
The synthesis of 22 2-aryl-1H-indoles, including 12 new compounds, has been achieved via Pd- or Rh-mediated methodologies, or selective electrophilic substitution. All three methods were based on elaborations from simple indole precursors. SAR studies on these indoles and 2-phenyl-1H-indole in Staphylococcus aureus as NorA efflux pump inhibitors indicated(More)