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1.
Integr Environ Assess Manag ; 15(6): 917-935, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31273905

ABSTRACT

Environmental challenges persist across the world, including the Australasian region of Oceania, where biodiversity hotspots and unique ecosystems such as the Great Barrier Reef are common. These systems are routinely affected by multiple stressors from anthropogenic activities, and increasingly influenced by global megatrends (e.g., the food-energy-water nexus, demographic transitions to cities) and climate change. Here we report priority research questions from the Global Horizon Scanning Project, which aimed to identify, prioritize, and advance environmental quality research needs from an Australasian perspective, within a global context. We employed a transparent and inclusive process of soliciting key questions from Australasian members of the Society of Environmental Toxicology and Chemistry. Following submission of 78 questions, 20 priority research questions were identified during an expert workshop in Nelson, New Zealand. These research questions covered a range of issues of global relevance, including research needed to more closely integrate ecotoxicology and ecology for the protection of ecosystems, increase flexibility for prioritizing chemical substances currently in commerce, understand the impacts of complex mixtures and multiple stressors, and define environmental quality and ecosystem integrity of temporary waters. Some questions have specific relevance to Australasia, particularly the uncertainties associated with using toxicity data from exotic species to protect unique indigenous species. Several related priority questions deal with the theme of how widely international ecotoxicological data and databases can be applied to regional ecosystems. Other timely questions, which focus on improving predictive chemistry and toxicology tools and techniques, will be important to answer several of the priority questions identified here. Another important question raised was how to protect local cultural and social values and maintain indigenous engagement during problem formulation and identification of ecosystem protection goals. Addressing these questions will be challenging, but doing so promises to advance environmental sustainability in Oceania and globally.


Subject(s)
Biodiversity , Climate Change , Ecotoxicology , Environmental Monitoring , Environmental Pollutants/adverse effects , Australasia , Environmental Exposure/adverse effects
2.
J Nat Prod ; 75(8): 1469-79, 2012 Aug 24.
Article in English | MEDLINE | ID: mdl-22880631

ABSTRACT

Phytochemical investigation of Chamaelirium luteum ("false unicorn") resulted in the isolation of 15 steroidal glycosides. Twelve of these (1, 2, 4-9, 11-13, and 15) are apparently unique to this species, and eight of these (6-9, 11-13, and 15) are previously unreported compounds; one (15) possesses a new steroidal aglycone. In addition, the absolute configuration of (23R,24S)-chiograsterol A (10) was defined, and its full spectroscopic characterization is reported for the first time. The structures and configurations of the saponins were determined using a combination of multistage mass spectrometry (MS(n)), 1D and 2D NMR experiments, and chemical degradation. The antiproliferative activity of nine compounds obtained in the present work, and eight related compounds generated in previous work, was compared in six human tumor cell lines, with aglycones 3 and 10 and related derivatives 16, 17, 19, and 20 all displaying significant antiproliferative activity.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Liliaceae/chemistry , Plants, Medicinal/chemistry , Saponins/isolation & purification , Saponins/pharmacology , Steroids/isolation & purification , Steroids/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Roots/chemistry , Saponins/chemistry , Steroids/chemistry
3.
J Nat Prod ; 74(7): 1557-60, 2011 Jul 22.
Article in English | MEDLINE | ID: mdl-21692443

ABSTRACT

Investigation of Chamaelirium luteum roots led to the isolation of two new steroidal saponins, helosides A and B, that contain a previously unreported aglycone, helogenin. Their structures and absolute configuration were elucidated through MS-MS, NMR, chemical degradation, and X-ray crystallography.


Subject(s)
Liliaceae/chemistry , Saponins/isolation & purification , Crystallography, X-Ray , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Roots/chemistry , Saponins/chemistry
4.
Chemistry ; 17(27): 7578-91, 2011 Jun 27.
Article in English | MEDLINE | ID: mdl-21598325

ABSTRACT

Chamaelirium luteum is used in traditional medicine systems and commercial botanical dietary supplements for the treatment of female reproductive health problems. Despite the wide use of this herb, only very limited phytochemical characterisation is available. Our investigation of C. luteum roots led to the isolation of two new steroidal saponins 1 and 2 that contain an unusual aglycone 3. The absolute configurations of these molecules were unable to be determined spectroscopically and thus the total synthesis of 3 was undertaken and achieved in 16 steps and 1.6 % overall yield from pregnenolone. The key step in the synthesis was the stereoselective installation of the side chain at C-17 and C-20, which employed anion-accelerated oxy-Cope methodology. The relative configuration of aglycone 3 was determined by X-ray crystallography of an advanced synthetic intermediate. The absolute configuration was based upon that of the pregnenolone-derived steroidal skeleton and determined to be 23R,24S.


Subject(s)
Phytosterols/chemical synthesis , Plants, Medicinal/chemistry , Saponins/chemistry , Crystallography, X-Ray , Models, Molecular , Molecular Conformation , Phytosterols/chemistry , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Saponins/isolation & purification , Stereoisomerism
5.
J Agric Food Chem ; 54(19): 7378-82, 2006 Sep 20.
Article in English | MEDLINE | ID: mdl-16968108

ABSTRACT

Vaccinium myrtillus or bilberry fruit is a commonly used herbal product. The usual method of determining the anthocyanin content is a single-wavelength spectrophotometric assay. Using this method, anthocyanin levels of two extracts were found to be 25% as claimed by the manufacturers. When high-performance liquid chromatography (HPLC) was used, however, one extract was found to contain 9% anthocyanins probably not derived from V. myrtillus but from an adulterant. This adulterant was subsequently identified, using HPLC, mass spectroscopy, and nuclear magnetic resonance, as amaranth, that is, 3-hydroxy-4-[(4-sulfo-1-naphthalenyl)azo]-2,7-naphthalenedisulfonic acid trisodium salt-a synthetic dark red sulfonic acid based naphthylazo dye. As described in this study, if deliberate adulteration occurs in an extract, a single-wavelength spectrophotometric assay is inadequate to accurately determine the levels of compounds such as anthocyanins. Detection of deliberate adulteration in commercial samples thus requires the use of alternative, more sophisticated, methods of analysis such as HPLC with photodiode array detection as a minimum.


Subject(s)
Amaranth Dye/analysis , Food Contamination/analysis , Fruit/chemistry , Vaccinium myrtillus/chemistry , Anthocyanins/analysis , Chromatography, High Pressure Liquid , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy , Mass Spectrometry
6.
Chem Commun (Camb) ; (5): 512-3, 2004 Mar 07.
Article in English | MEDLINE | ID: mdl-14973583

ABSTRACT

Novel cyclopropyl containing fatty acids are good substrates for P450(BM3) catalysed hydroxylation and analysis of their oxidation products indicates the presence of a radical intermediate (maximum rebound rate 2.6 x 10(10) s(-1)) and the absence of any cationic intermediate.


Subject(s)
Bacterial Proteins/metabolism , Cytochrome P-450 Enzyme System/metabolism , Fatty Acids/metabolism , Mixed Function Oxygenases/metabolism , Cations/chemistry , Fatty Acids/chemistry , Gas Chromatography-Mass Spectrometry , Hydroxylation , Magnetic Resonance Spectroscopy , Molecular Conformation , NADPH-Ferrihemoprotein Reductase , Oxidation-Reduction
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