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Gericke O, Fowler RM, Heskes AM, Bayly MJ, Semple SJ, Ndi CP, Stærk D, Løland CJ, Murphy DJ, Buirchell BJ, Møller BL. Navigating through chemical space and evolutionary time across the Australian continent in plant genus Eremophila. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:555-578. [PMID: 34324744 PMCID: PMC9292440 DOI: 10.1111/tpj.15448] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 06/07/2021] [Accepted: 07/22/2021] [Indexed: 05/13/2023]
Abstract
Eremophila 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. Unique and structurally diverse metabolites, particularly diterpenoids, are also a feature of plants in this group. To assess the full dimension of the chemical space of the tribe Myoporeae, we investigated the metabolite diversity in a chemo-evolutionary framework applying a combination of molecular phylogenetic and state-of-the-art computational metabolomics tools to build a dataset involving leaf samples from a total of 291 specimens of Eremophila and allied genera. The chemo-evolutionary relationships are expounded into a systematic context by integration of information about leaf morphology (resin and hairiness), environmental factors (pollination and geographical distribution), and medicinal properties (traditional medicinal uses and antibacterial studies), augmenting our understanding of complex interactions in biological systems.
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Affiliation(s)
- Oliver Gericke
- Plant Biochemistry LaboratoryDepartment of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDK‐1871Denmark
| | - Rachael M. Fowler
- School of BioSciencesThe University of MelbourneParkvilleVic.3010Australia
| | - Allison M. Heskes
- Plant Biochemistry LaboratoryDepartment of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDK‐1871Denmark
| | - Michael J. Bayly
- School of BioSciencesThe University of MelbourneParkvilleVic.3010Australia
| | - Susan J. Semple
- Quality Use of Medicines and Pharmacy Research CentreSchool of Pharmacy and Medical SciencesUniversity of South AustraliaAdelaideSA5000Australia
| | - Chi P. Ndi
- Quality Use of Medicines and Pharmacy Research CentreSchool of Pharmacy and Medical SciencesUniversity of South AustraliaAdelaideSA5000Australia
| | - Dan Stærk
- Department of Drug Design and PharmacologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDK‐2100Denmark
| | - Claus J. Løland
- Department of NeuroscienceFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDK‐2100Denmark
| | | | | | - Birger Lindberg Møller
- Plant Biochemistry LaboratoryDepartment of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDK‐1871Denmark
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Gericke O, Hansen NL, Pedersen GB, Kjaerulff L, Luo D, Staerk D, Møller BL, Pateraki I, Heskes AM. Nerylneryl diphosphate is the precursor of serrulatane, viscidane and cembrane-type diterpenoids in Eremophila species. BMC PLANT BIOLOGY 2020; 20:91. [PMID: 32111159 PMCID: PMC7049213 DOI: 10.1186/s12870-020-2293-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/17/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Eremophila R.Br. (Scrophulariaceae) is a diverse genus of plants with species distributed across semi-arid and arid Australia. It is an ecologically important genus that also holds cultural significance for many Indigenous Australians who traditionally use several species as sources of medicines. Structurally unusual diterpenoids, particularly serrulatane and viscidane-types, feature prominently in the chemical profile of many species and recent studies indicate that these compounds are responsible for much of the reported bioactivity. We have investigated the biosynthesis of diterpenoids in three species: Eremophila lucida, Eremophila drummondii and Eremophila denticulata subsp. trisulcata. RESULTS In all studied species diterpenoids were localised to the leaf surface and associated with the occurrence of glandular trichomes. Trichome-enriched transcriptome databases were generated and mined for candidate terpene synthases (TPS). Four TPSs with diterpene biosynthesis activity were identified: ElTPS31 and ElTPS3 from E. lucida were found to produce (3Z,7Z,11Z)-cembratrien-15-ol and 5-hydroxyviscidane, respectively, and EdTPS22 and EdtTPS4, from E. drummondii and E. denticulata subsp. trisulcata, respectively, were found to produce 8,9-dihydroserrulat-14-ene which readily aromatized to serrulat-14-ene. In all cases, the identified TPSs used the cisoid substrate, nerylneryl diphosphate (NNPP), to form the observed products. Subsequently, cis-prenyl transferases (CPTs) capable of making NNPP were identified in each species. CONCLUSIONS We have elucidated two biosynthetic steps towards three of the major diterpene backbones found in this genus. Serrulatane and viscidane-type diterpenoids are promising candidates for new drug leads. The identification of an enzymatic route to their synthesis opens up the possibility of biotechnological production, making accessible a ready source of scaffolds for further modification and bioactivity testing.
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Affiliation(s)
- Oliver Gericke
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Nikolaj Lervad Hansen
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Gustav Blichfeldt Pedersen
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Louise Kjaerulff
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100, Copenhagen, Denmark
| | - Dan Luo
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Dan Staerk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100, Copenhagen, Denmark
| | - Birger Lindberg Møller
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Irini Pateraki
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Allison Maree Heskes
- Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark.
- Center for Synthetic Biology "bioSYNergy", Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark.
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Sadgrove NJ, Hitchcock M, Watson K, Jones GL. Chemical and biological characterization of novel essential oils from Eremophila bignoniiflora (F. Muell) (Myoporaceae): a traditional Aboriginal Australian bush medicine. Phytother Res 2013. [PMID: 23193085 DOI: 10.1002/ptr.4889] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Essential oils were extracted by hydrodistillation from the traditional Australian medicinal plant Eremophila bignoniiflora, characterized chemically and then screened for bioactivity. Characterization and quantification were completed using gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection, respectively. Antimicrobial capacity was assessed using disc diffusion and micro-titre plate broth dilution and further characterized using thin layer chromatography followed by bioautography to assign activity to separated individual active components. Antifungal capacity was investigated using micro-titre plate broth dilution against pathogenic Trichophyton species. Free radical scavenging ability was assessed using the diphenylpicrylhydradyl reaction in methanol. The predominant components of the essential oil were fenchyl-acetate and bornyl-acetate. However, bioautography indicated antimicrobial ability to be largely linked to the less abundant, more polar constituents. Oils displayed only modest antifungal ability against pathogenic Trichophyton species associated with dermatophytosis, but moderate to high antimicrobial activity, particularly against the yeast Candida albicans and the bacteria Staphylococcus epidermidis. Essential oils exhibited relatively low free radical scavenging ability. Speculation over the role of essential oils in the traditional medicinal applications of E. bignoniiflora follows, exploring correlations between traditional use and investigated bioactivities.
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Affiliation(s)
- Nicholas John Sadgrove
- University of New England, Pharmaceuticals, Nutraceuticals Group for Bioactive Discovery in Health and Ageing, Armidale, New South Wales, Australia
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Barnes EC, Kavanagh AM, Ramu S, Blaskovich MA, Cooper MA, Davis RA. Antibacterial serrulatane diterpenes from the Australian native plant Eremophila microtheca. PHYTOCHEMISTRY 2013; 93:162-9. [PMID: 23602054 DOI: 10.1016/j.phytochem.2013.02.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/22/2013] [Accepted: 02/28/2013] [Indexed: 05/22/2023]
Abstract
Chemical investigations of the aerial parts of the Australian plant Eremophila microtheca resulted in the isolation of three serrulatane diterpenoids, 3-acetoxy-7,8-dihydroxyserrulat-14-en-19-oic acid (1), 3,7,8-trihydroxyserrulat-14-en-19-oic acid (2) and 3,19-diacetoxy-8-hydroxyserrulat-14-ene (3) as well as the previously reported compounds verbascoside (4) and jaceosidin (5). Acetylation and methylation of the major serrulatane diterpenoid 2 afforded 3,8-diacetoxy-7-hydroxyserrulat-14-en-19-oic acid (6) and 3,7,8-trihydroxyserrulat-14-en-19-oic acid methyl ester (7), respectively. The antibacterial activity of 1-7 was assessed against a panel of Gram-positive and Gram-negative bacterial isolates. All of the serrulatane compounds exhibited moderate activity against Streptococcus pyogenes (ATCC 12344) with minimum inhibitory concentrations (MICs) ranging from 64-128 μg/mL. Serrulatane 1 demonstrated activity against all Gram-positive bacterial strains (MICs 64-128 μg/mL) except for Enterococcus faecalis and Enterococcus faecium. This is the first report of natural products from E. microtheca.
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Affiliation(s)
- Emma C Barnes
- Eskitis Institute, Griffith University, Nathan, Qld 4111, Australia
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Sadgrove NJ, Jones GL. Chemical and biological characterisation of solvent extracts and essential oils from leaves and fruit of two Australian species of Pittosporum (Pittosporaceae) used in aboriginal medicinal practice. JOURNAL OF ETHNOPHARMACOLOGY 2013; 145:813-21. [PMID: 23274743 DOI: 10.1016/j.jep.2012.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 12/12/2012] [Accepted: 12/14/2012] [Indexed: 05/24/2023]
Abstract
ETHNOPHARMACOLOGICAL SIGNIFICANCE Although no known medicinal use for Pittosporum undulatum Vent. (Pittosporaceae) has been recorded, anecdotal evidence suggests that Australian Aboriginal people used Pittosporum angustifolium Lodd., G. Lodd. & W. Lodd. topically for eczema, pruritis or to induce lactation in mothers following child-birth and internally for coughs, colds or cramps. AIMS OF THE STUDY Essential oil composition and bioactivity as well as differential solvent extract antimicrobial activity from Pittosporum angustifolium are investigated here first, to partially describe the composition of volatiles released in traditional applications of Pittosporum angustifolium for colds or as a lactagogue, and second to investigate antibacterial activity related to topical applications. Essential oils were also investigated from Pittosporum undulatum Vent., first to enhance essential oil data produced in previous studies, and second as a comparison to Pittosporum angustifolium. MATERIALS AND METHODS Essential oils were hydrodistilled from fruit and leaves of both species using a modified approach to lessen the negative (frothing) effect of saponins. This was achieved by floating pumice or pearlite obsidian over the mixture to crush the suds formed while boiling. Essential oil extracts were analysed using GC-MS, quantified using GC-FID then screened for antimicrobial activity using a micro-titre plate broth dilution assay (MIC). Using dichloromethane, methanol, hexane and H(2)O as solvents, extracts were produced from leaves and fruit of Pittosporum angustifolium and screened for antimicrobial activity and qualitative phytochemical character. RESULTS Although the essential oil from leaves and fruit of Pittosporum undulatum demonstrated some component variation, the essential oil from fruits of Pittosporum angustifolium had major constituents that strongly varied according to the geographical location of collection, suggesting the existence of at least two chemotypes; one with high abundance of acetic acid decyl ester. This chemotype had high antimicrobial activity whilst the other chemotype had only moderate antimicrobial activity against the three microbial species investigated here. This result may support the occurrence of geographical specificity with regard to ethnopharmacological use. Antimicrobial activity screening of the solvent extracts from Pittosporum angustifolium revealed the leaves to be superior to fruit, with water being the most suitable extraction solvent. CONCLUSION To the best of our knowledge, this study constitutes the first time essential oils, and solvent extracts from the fruits of Pittosporum angustifolium, have been examined employing comprehensive chemical and biological analysis. The essential oil composition presented in this paper, includes components with structural similarity as chemosemiotic compounds involved in mother-infant identification, which may have significance with regard to traditional applications as a lactagogue.
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Affiliation(s)
- Nicholas John Sadgrove
- Pharmaceuticals and Nutraceuticals Group, Centre for Bioactive Discovery in Health and Ageing, School of Science and Technology, University of New England, Armidale 2351, Australia.
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Dinardo MM, Camerino G, Mele A, Latorre R, Conte Camerino D, Tricarico D. Splicing of the rSlo gene affects the molecular composition and drug response of Ca2+-activated K+ channels in skeletal muscle. PLoS One 2012; 7:e40235. [PMID: 22808126 PMCID: PMC3393747 DOI: 10.1371/journal.pone.0040235] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 06/03/2012] [Indexed: 12/02/2022] Open
Abstract
The molecular composition and drug responses of calcium-activated K+ (BK) channels of skeletal muscle are unknown. Patch-clamp experiments combined with transcript scanning of the Kcnma1 gene encoding the alpha subunit of the BK channel were performed in rat slow-twitch soleus (Sol) and fast-twitch flexor digitorum brevis (FDB) skeletal muscles. Five splicing products of the Kcnma1 gene were isolated from Sol and FDB: the e17, e22, +29 aa, Slo27 and Slo0 variants. RT-PCR analysis demonstrated that the expression of e22 and Slo0 were 80–90% higher in FDB than Sol, whereas the expression of Slo27 was 60% higher in Sol than FDB, and the +29 aa variant was equally expressed in both muscle types. No beta 1-4 subunits were detected. In Sol, a large BK current with low Ca2+ sensitivity was recorded. The BK channel of Sol also showed a reduced response to BK channel openers, such as NS1619, acetazolamide and related drugs. In FDB, a reduced BK current with high Ca2+ sensitivity and an enhanced drug response was recorded. The total BK RNA content, which was 200% higher in Sol than in FDB, correlated with the BK currents in both muscles. Drug responses primarily correlated with e22 and Slo0 expression levels in FDB and to Slo27 expression in Sol muscle. In conclusion, phenotype-dependent BK channel biophysical and pharmacological properties correlated with the expression levels of the variants in muscles. These findings may be relevant to conditions affecting postural muscles, such as prolonged bed-rest, and to diseases affecting fast-twitch muscles, such as periodic paralysis. Down-regulation or up-regulation of the variants associated with pathological conditions may affect channel composition and drug responses.
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Affiliation(s)
| | - Giulia Camerino
- Departments of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
| | - Antonietta Mele
- Departments of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso, Chile
| | - Diana Conte Camerino
- Departments of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
| | - Domenico Tricarico
- Departments of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
- * E-mail:
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Packer J, Brouwer N, Harrington D, Gaikwad J, Heron R, Ranganathan S, Vemulpad S, Jamie J. An ethnobotanical study of medicinal plants used by the Yaegl Aboriginal community in northern New South Wales, Australia. JOURNAL OF ETHNOPHARMACOLOGY 2012; 139:244-255. [PMID: 22101358 DOI: 10.1016/j.jep.2011.11.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 10/20/2011] [Accepted: 11/06/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Documentation of Australian bush medicines is of utmost importance to the preservation of this disappearing and invaluable knowledge. This collaboration between the Yaegl Aboriginal community in northern New South Wales (NSW), Australia and an academic institution, demonstrates an effective means of preserving and adding value to this information. MATERIALS AND METHODS Questionnaire-guided interviews were performed with community Elders under a framework of participatory action research. Medicinal plant knowledge was collated in a handbook to aid interviews and to be used as an ongoing resource by the community. Specimens for all non-cultivar plants that were discussed were collected and deposited in herbaria with unique voucher numbers. This medicinal knowledge was checked against the literature for reports of related use and studies of biological activity. RESULTS Nineteen Elders were interviewed, leading to discussions on fifty four plant preparations used for medicinal purposes. These plant preparations involved thirty two plants coming from twenty one families, reflecting the botanical diversity of the area. The plants retained in the Yaegl pharmacopoeia correspond to their accessibility and ease of preparation, reflected in their ongoing utilisation. Several plant uses did not appear elsewhere in the literature. CONCLUSIONS This study is the first comprehensive documentation of the medicinal knowledge of the Yaegl Aboriginal community. It has been conducted using participatory action research methods and adds to the recorded customary knowledge of the region. The customary medicinal knowledge retained by the Yaegl Aboriginal community is related to the evolving needs of the community and accessibility of plants.
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Affiliation(s)
- Joanne Packer
- Indigenous Bioresources Research Group, Macquarie University, North Ryde, Sydney 2109, Australia.
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Anakok O, Ndi C, Barton M, Griesser H, Semple S. Antibacterial spectrum and cytotoxic activities of serrulatane compounds from the Australian medicinal plant Eremophila neglecta. J Appl Microbiol 2011; 112:197-204. [DOI: 10.1111/j.1365-2672.2011.05174.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Suyama TL, Cao Z, Murray TF, Gerwick WH. Ichthyotoxic brominated diphenyl ethers from a mixed assemblage of a red alga and cyanobacterium: structure clarification and biological properties. Toxicon 2009; 55:204-10. [PMID: 19638282 DOI: 10.1016/j.toxicon.2009.07.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 07/16/2009] [Accepted: 07/22/2009] [Indexed: 11/29/2022]
Abstract
Primary fractions from the extract of a tropical red alga mixed with filamentous cyanobacteria, collected from Papua New Guinea, were active in a neurotoxicity assay. Bioassay-guided isolation led to two natural products (1,2) with relatively potent calcium ion influx properties. The more prevalent of the neurotoxic compounds (1) was characterized by extensive NMR, mass spectrometry, and X-ray crystallography, and shown to be identical to a polybrominated diphenyl ether metabolite present in the literature, but reported with different NMR properties. To clarify this anomalous result, we synthesized a candidate isomeric polybrominated diphenyl ether (3), but this clearly had different NMR shifts than the reported compound. We conclude that the original isolate of 3,4,5-tribromo-2-(2,4-dibromophenoxy)phenol was contaminated with a minor compound, giving rise to the observed anomalous NMR shifts. The second and less abundant natural product (2) isolated in this study was a more highly brominated species. All three compounds showed a low micromolar ability to increase intracellular calcium ion concentrations in mouse neocortical neurons as well as toxicity to zebrafish. Because polybrominated diphenyl ethers have both natural as well as anthropomorphic origins, and accumulate in marine organisms at higher trophic level (mammals, fish, birds), these neurotoxic properties are of environmental significance and concern.
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Affiliation(s)
- Takashi L Suyama
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, MC 0212, La Jolla, CA 92093-0212, USA
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Dai G, Haedo RJ, Warren VA, Ratliff KS, Bugianesi RM, Rush A, Williams ME, Herrington J, Smith MM, McManus OB, Swensen AM. A High-Throughput Assay for Evaluating State Dependence and Subtype Selectivity of Cav2 Calcium Channel Inhibitors. Assay Drug Dev Technol 2008; 6:195-212. [DOI: 10.1089/adt.2008.136] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Ge Dai
- Merck Research Laboratories, Rahway, NJ
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Liu Q, Harrington D, Kohen JL, Vemulpad S, Jamie JF. Bactericidal and cyclooxygenase inhibitory diterpenes from Eremophila sturtii. PHYTOCHEMISTRY 2006; 67:1256-61. [PMID: 16759677 DOI: 10.1016/j.phytochem.2006.04.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 04/04/2006] [Accepted: 04/12/2006] [Indexed: 05/10/2023]
Abstract
Two serrulatane diterpenes, 3,8-dihydroxyserrulatic acid (1) and serrulatic acid (2), have been isolated from Eremophila sturtii through bioassay-guided fractionation. These compounds inhibit the inflammation pathway enzymes cyclooxygenase 1 and 2, and exhibit bactericidal activity against Staphylococcus aureus.
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Affiliation(s)
- Qian Liu
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
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Hemstapat K, Smith MT, Monteith GR. Measurement of intracellular Ca2+ in cultured rat embryonic hippocampal neurons using a fluorescence microplate reader: potential application to biomolecular screening. J Pharmacol Toxicol Methods 2004; 49:81-7. [PMID: 14990332 DOI: 10.1016/j.vascn.2003.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2003] [Accepted: 10/01/2003] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Fluorescence microplate readers for the measurement of cytosolic free Ca(2+) ([Ca(2+)](i)) are used as a drug screening tool, particularly for immortal cell lines. However, wider application of this methodological approach to more differentiated cells such as neurons would also be useful for the screening of compounds that modulate synaptic transmission. Such an approach has the potential to identify lead compounds for the development of novel drugs for the treatment of epilepsy, pathological pain states, Parkinson's disease, or other neurological disorders. METHODS In this paper, we describe the development of a microplate reader assay for the assessment of [Ca(2+)](i) in a primary culture of rat hippocampal neurons maintained in Neurobasal medium using the fluorescent calcium indicator, fluo-3. RESULTS The assay was appropriate for the screening of glutamate receptor agonists and antagonists. Furthermore, lowering the extracellular Mg(2+) concentration ([Mg(2+)](O)) produced consistent oscillations in neuronal [Ca(2+)](i) detected using the fluorescence microplate reader. These oscillations were inhibited by the GABA(B) agonist, baclofen, and the NMDA receptor antagonist, LY274614. DISCUSSION Our results indicate that assessment of the inhibitory effects of agents on spontaneous [Ca(2+)](i) oscillations in neurons may be useful for the identification of agents that act on targets for which specific screening methods are not currently available, or those which act via a previously unknown pathway to inhibit synaptic transmission. This technique also has the potential to increase the productivity of experiments designed to characterize changes in [Ca(2+)](i) (including calcium oscillations) in cultured neurons.
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Affiliation(s)
- Kamondanai Hemstapat
- School of Pharmacy, University of Queensland, St. Lucia Campus, Brisbane, Queensland, 4072, Australia
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Boo YC, Sorescu GP, Bauer PM, Fulton D, Kemp BE, Harrison DG, Sessa WC, Jo H. Endothelial NO synthase phosphorylated at SER635 produces NO without requiring intracellular calcium increase. Free Radic Biol Med 2003; 35:729-41. [PMID: 14583337 DOI: 10.1016/s0891-5849(03)00397-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Shear stress stimulates NO production involving the Ca2+-independent mechanisms in endothelial cells. We have shown that exposure of bovine aortic endothelial cells (BAEC) to shear stress stimulates phosphorylation of eNOS at S635 and S1179 by the protein kinase A- (PKA-) dependent mechanisms. We examined whether phosphorylation of S635 of eNOS induced by PKA stimulates NO production in a calcium-independent manner. Expression of a constitutively active catalytic subunit of PKA (Cqr) in BAEC induced phosphorylation of S635 and S1179 residues and dephosphorylation of T497. Additionally, Cqr expression stimulated NO production, which could not be prevented by treating cells with the intracellular calcium chelator BAPTA-AM. To determine the role of each eNOS phosphorylation site in NO production, HEK-293 cells transfected with eNOS point mutants whereby S116, T497, S635, and S1179 were mutated to either A or D. Maximum NO production from S635D-expressing cells was significantly higher than that of either wild type or S635A in both basal and elevated [Ca2+]i conditions. More interestingly, S635D cells produced NO even when [Ca2+]i was nearly depleted by BAPTA-AM. We confirmed these results obtained in HEK-293 cells in BAEC transfected with S635D, S635A, or wild-type eNOS vector. These findings suggest that, once phosphorylated at S635 residue, eNOS produces NO without requiring any changes in [Ca2+]i. PKA-dependent phosphorylation of eNOS S635 and subsequent basal NO production in a Ca2+-independent manner may play an important role in regulating vascular biology and pathophysiology.
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Affiliation(s)
- Yong Chool Boo
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Institute of Technology and Emory University, Emory University School of Medicine, Atlanta, GA 30322, USA
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