Previously undescribed eremane, viscidane, and isozizaene diterpenoids, eremorigidanes A-F, along with six known O-methylated flavonoids and three known triterpenoids were isolated and identified from the leaves of Eremophila rigida Chinnock by combined use of high-resolution PTP1B inhibition profiling, semipreparative- and analytical-scale HPLC separations, HPLC-PDA-HRMS analysis, and NMR spectroscopy. The absolute configuration of the unreported diterpenoids were determined by comparison of their experimental and calculated ECD spectra as well as by biosynthetic arguments. All isolates were evaluated for their PTP1B inhibitory activities, which revealed the flavonoid penduletin (3) to show inhibition with an IC value of 18.
View Article and Find Full Text PDFSerrulatanes constitute a class of unique diterpenoids derived from all- nerylneryl diphosphate rather than the conventional all- diterpenoid precursor geranylgeranyl diphosphate and thus provide an intriguing expansion of the chemical space of plant specialized metabolites. Plants of the Australian genus are rich sources of structurally diverse serrulatanes. Here, we report the identification of 15 hitherto undescribed serrulatanes (eremoculatanes A-N), together with 16 previously reported compounds, from the EtOAc extract of leaves.
View Article and Find Full Text PDFThe inhibition of efflux pumps is a promising approach to combating multidrug-resistant bacteria. We have developed a combined structure- and ligand-based model, using OpenEye software, for the identification of inhibitors of AcrB, the inner membrane protein component of the AcrAB-TolC efflux pump in . From a database of 1391 FDA-approved drugs, 23 compounds were selected to test for efflux inhibition in .
View Article and Find Full Text PDFIn this study, an extract of the leaves of Eremophila clarkei Oldfield & F.Muell. showed protein tyrosine phosphatase 1B (PTP1B) inhibitory activity with an IC value of 33.
View Article and Find Full Text PDFExtracts of subsp. showed α-glucosidase and PTP1B inhibitory activity with IC values of 19.6 and 13.
View Article and Find Full Text PDFDiscovery of sustainable and benign-by-design drugs to combat emerging health pandemics calls for new analytical technologies to explore the chemical and pharmacological properties of Nature's unique chemical space. Here, we present a new analytical technology workflow, polypharmacology-labeled molecular networking (PLMN), where merged positive and negative ionization tandem mass spectrometry-based molecular networking is linked with data from polypharmacological high-resolution inhibition profiling for easy and fast identification of individual bioactive constituents in complex extracts. The crude extract of was subjected to PLMN analysis for the identification of antihyperglycemic and antibacterial constituents.
View Article and Find Full Text PDFA series of novel benzo[h]chromene compounds were designed, synthesized and evaluated for their biological activity as AcrB inhibitors. The compounds were assessed for their ability to potentiate the effect of antibiotics. Compounds with antibiotic-potentiating effects were then evaluated for inhibition of Nile Red efflux, and for off-target effects including activity on the outer and inner bacterial membranes and toxicity.
View Article and Find Full Text PDFis a pathogen with high intrinsic antimicrobial resistance while multidrug resistant (MDR) and extensively drug resistant (XDR) strains of this pathogen are emerging. Treatment options for infections by these strains are very limited, hence new therapies are urgently needed. The bacterial cell division protein, FtsZ, is a promising drug target for the development of novel antimicrobial agents.
View Article and Find Full Text PDFThe plant genus Eremophila is endemic to Australia and widespread in arid regions. Root bark extract of Eremophila longifolia (R.Br.
View Article and Find Full Text PDFIn a cross-continental research initiative, including researchers working in Australia and Denmark, and based on joint external funding by a 3-year grant from the Novo Nordisk Foundation, we have used DNA sequencing, extensive chemical profiling and molecular networking analyses across the entire Eremophila genus to provide new knowledge on the presence of natural products and their bioactivities using polypharmocological screens. Sesquiterpenoids, diterpenoids and dimers of branched-chain fatty acids with previously unknown chemical structures were identified. The collection of plant material from the Eremophila genus was carried out according to a 'bioprospecting agreement' with the Government of Western Australia.
View Article and Find Full Text PDFIntroduction: Medication-related problems often lead to patient harm. This paper aims to review the Australian literature to determine the overall incidence, severity and preventability of medication-related hospital admissions, as well as providing a national estimate on their extent and cost.
Methods: The first part of the paper includes a literature search to identify studies that provided estimates of medication-related problems that caused hospital admissions.
Eremophila (Scrophulariaceae) is a genus of Australian desert plants, which have been used by Australian Aboriginal people for various medicinal purposes. Crude extracts of the leaf resin of Eremophila glabra (R.Br.
View Article and Find Full Text PDFMultidrug resistance (MDR) is a major challenge in cancer treatment, and the breast cancer resistance protein (BCRP) is an important target in the search for new MDR-reversing drugs. With the aim of discovering new potential BCRP inhibitors, the crude extract of leaves of , a plant endemic to Australia, was investigated for inhibitory activity of parental (HT29) as well as BCRP-overexpressing HT29 colon cancer cells resistant to the chemotherapeutic SN-38 (i.e.
View Article and Find Full Text PDFAdvanced glycation end products (AGEs) are formed via non-enzymatic reactions between amino groups of proteins and the carbonyl groups of reducing sugars. Previous studies have shown that highly glycated albumin prepared using a glucose-bovine serum albumin (Glu-BSA) model system incubated at 60°C for 6 weeks induces genotoxicity in WIL2-NS cells at 9 days of exposure measured by the cytokinesis-block micronucleus cytome (CBMNcyt) assay. However, this AGE model system is not physiologically relevant as normal body temperature is 37°C and the degree of glycation may exceed the extent of albumin modification in vivo.
View Article and Find Full Text PDFBioactivity-guided fraction of an extract of to identify antibacterial compounds against , led to the isolation of two new compounds, (2″)-5-methoxy-7-hydroxy-8-lavandulylchromone (13) and (2,)-(-)-sophobiflavonoid CE (19), and 18 known flavonoids, (6a,11a)-(-)-maackiain (1), (2)-(-)-8-prenylnaringenin (2), (2)-(-)-exiguaflavanone K (3), (2)-(-)-sophoraflavanone G (4), (2)-(-)-leachianone A (5), (2)-(-)-kushenol E (6), (2)-(-)-leachianone G (7), (±)-kushenol F (8), (2)-(-)-kurarinone (9), (2)-(-)-kurarinol (10), (2 ,3)- (+)-3,7,4'-trihydroxy-5-methoxy-8-prenylflavanone (11), (2)-(-)-isoxanthohumol (12), (2)-(-)-2'-methoxykurarinone (14), (2 ,3)-(+)-kushenol I (15), calycosin (16), kuraridin (17), (2)-(-)-kushenol A (18), and trifolirhizin (20). Their structures were elucidated based on NMR, MS, and CD spectroscopic analysis. Among them, , , , and exerted modest antibacterial activity against , with MIC of 128-256 μg/mL for and 256-512 μg/mL for , and .
View Article and Find Full Text PDFEremophila is the largest genus in the plant tribe Myoporeae (Scrophulariaceae) and exhibits incredible morphological diversity across the Australian continent. The Australian Aboriginal Peoples recognize many Eremophila species as important sources of traditional medicine, the most frequently used plant parts being the leaves. Recent phylogenetic studies have revealed complex evolutionary relationships between Eremophila and related genera in the tribe.
View Article and Find Full Text PDFThe bacterial cell division protein, FtsZ, has been identified as a target for antimicrobial development. Derivatives of 3-methoxybenzamide have shown promising activities as FtsZ inhibitors in Gram-positive bacteria. We sought to characterise the activity of five difluorobenzamide derivatives with non-heterocyclic substituents attached through the 3-oxygen.
View Article and Find Full Text PDFAcidic compounds were enriched from a water decoction of Portulaca oleracea using 717 anion exchange resin column chromatography. A total of 22 compounds including 9 catecholamine derivatives, of which six were rare sulfonic acid derivatives, and 9 nitro derivatives, were further isolated through various column chromatographic methods, and their structures were elucidated by interpreting their spectroscopic data and ECD calculations. Among them, 16 compounds were isolated from P.
View Article and Find Full Text PDFNovel 4-substituted quinazoline-2-carboxamide derivatives targeting AcrB were designed, synthesized and evaluated for their biological activity as AcrB inhibitors. In particular, the ability of the compounds to potentiate the activity of antibiotics, to inhibit Nile Red efflux and to target AcrB was investigated. In this study, 19 compounds were identified to reduce the MIC values of at least one tested antibacterial by 2- to 16-fold at a lower concentration.
View Article and Find Full Text PDFAdvanced glycation end-products (AGEs) may be a contributing factor in the development of diabetes-specific vascular pathologies that affect the retina, glomerulus and peripheral nerves. In this study, Australian native food plant species Syzygium paniculatum was investigated for activities relevant to Type 2 diabetes mellitus including inhibition of α-amylase, α-glucosidase and protein glycation. A methanolic extract of the leaves showed the strongest α-amylase inhibition (IC = 14.
View Article and Find Full Text PDFThe cytokinesis-block micronucleus cytome (CBMNcyt) assay is a comprehensive method to measure DNA damage, cytostasis and cytotoxicity caused by nutritional, radiation and chemical factors. A slide imaging technique has been identified as a new method to assist with the visual scoring of cells for the CBMNcyt assay. A NanoZoomer S60 Digital Pathology slide scanner was used to view WIL2-NS cells treated with hydrogen peroxide (H2O2) and measure CBMNcyt assay biomarkers using a high-definition desktop computer screen.
View Article and Find Full Text PDFTen new branched-chain fatty acid (BCFA) dimers with a substituted cyclohexene structure, five new monomers, and two known monomers, (2,4,6)-5-(acetoxymethyl)tetradeca-2,4,6-trienoic acid and its 5-hydroxymethyl analogue, were identified in the leaf extract of subsp. using a combination of HPLC-PDA-HRMS-SPE-NMR analysis and semipreparative-scale HPLC. The dimers could be classified as three types of Diels-Alder reaction products formed between monomers at two different sites of unsaturation of the dienophile.
View Article and Find Full Text PDFFrom July to August 2016, 4 homeless people who injected drugs (PWID) with acute or recent hepatitis C virus (HCV) infection were reported in Belfast. A multidisciplinary team including public health, homeless and addiction services undertook an investigation to identify risk behaviours and interrupt transmission chains. Recent HCV cases were defined as negative test within the previous year, or reported injecting for less than 1 year; acute cases had tested negative within the previous 6 months.
View Article and Find Full Text PDFPlants in the Australian genus (Scrophulariaceae) have attracted considerable recent attention for their antimicrobial compounds, which possess a wide range of chemical structures. As they are typically associated with the oily-waxy resin layer covering leaves and green branchlets, and is prominent among the species containing a pronounced sticky resin layer, this species was considered of interest for assessing its antibacterial constituents. The -hexane fraction of the crude acetone extract of the leaves exhibited antibacterial activity against .
View Article and Find Full Text PDFA novel series of 5-methyl-2-phenylphenanthridium derivatives were displayed outstanding activity against a panel of antibiotic-sensitive and -resistant bacteria strains compared with their precursor sanguinarine, ciprofloxacin and oxacillin sodium. Compounds 7 l, 7m and 7n were found to display the most effective activity against five sensitive strains (0.06-2 μg/mL) and three resistant strains (0.
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