http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11132 Chemical investigation of seven species from the brown algal genus Cystophora collected throughout Australia and New Zealand resulted in the isolation of two new compounds, 9,10-farnesylacetone epoxide (1) from Cystophora moniliformis and 1′-(2′,4′,6′-trihydroxyphenyl)-13-hydroxyoctadeca-6Z,9Z,11E,15Z-tetraen-1-one (12) from Cystophora scalaris, and 16 others that have been previously reported. Structures were elucidated using spectrometric methods, particularly 1D and 2D NMR spectroscopy. Taxonomic implications of the chemical findings are discussed including the possibility that 1 may be an intra-specific marker for the Western Australian population of C. moniliformis, and that 12 may be diagnostic for populations of C. scalaris from New Zealand waters. 2012-07-29T23:13:41.924Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8135 Post combustion capture, PCC, of CO₂ from the flue gas stream of coal fired power stations is an attractive proposition for the reduction of CO₂ output into the atmosphere. PCC based on reversible absorption by aqueous amine solution is probably the most advanced technology. Thus the investigation of the chemistry of CO₂ absorption by such solutions is of crucial importance. A critical reaction is the formation of carbamates. There is a vast literature on this process but it is mainly based on empirical reaction mechanisms. In this contribution we present a molecularly correct mechanism for carbamate formation with primary amines. The results are derived from detailed, ¹H-NMR based, kinetic and equilibrium investigation of the interaction of monoethanolamine, MEA, with carbonate species. All rate and equilibrium constants are reported. 2011-07-06T06:00:07.904Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7404 Investigation of an extract of the Australian marine sponge Psammoclema sp. for dynamin I inhibitory activity led to the isolation of four new trihydroxysterols (1−4) related to aragusterol G. These compounds were largely identified by 1D and 2D NMR spectroscopic methods. While 1 was found to be inactive in the dynamin bioassay, bioassays did reveal that compounds 1−4 inhibited the growth of colorectal, breast, ovarian, and prostate cancer cell lines (GI₅₀ 5−27 μM). The additional insight that these new compounds give to previous SAR studies is discussed briefly. 2011-03-16T05:10:07.503Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1181 Six cyclised tetraprenyltoluquinols and five stereoisomers with the previously reported amentol skeleton have been isolated from the lipophilic extract of the South African brown alga Cystophora fibrosa. Structures and relative stereochemistry were determined using spectrometric techniques, particularly 1D and 2D NMR, and molecular modelling experiments. The compounds isolated appear to be enantiomeric to compounds with the same skeleton isolated from brown algae of the genus Cystoseira collected in northern Africa and the Mediterranean Sea. The isolation of tetraprenyltoluquinols with the amentol skeleton from this alga suggests that C. fibrosa should be moved from the genus Cystophora into the Cystoseira. 2010-04-27T06:38:28.144Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1180 Flavonoids (1–4), together with ten known compounds (5–14) were isolated from the stems and roots of the mangrove plant Derris indica. Their chemical structures were elucidated by analysis of their spectroscopic data. All compounds except compounds 2 and 6 exhibited antimycobacterial activity with minimum inhibitory concentrations (MIC) between 6.25 and 200 μg/mL. 2010-04-27T06:38:13.581Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1804 The structure of trisphaerolide A (1), a mildly cytotoxic metabolite isolated from extracts of the marine sponge Erylus trisphaerus collected in Dominica, has been elucidated by detailed analysis of spectroscopic data. Trisphaerolide A (1) has a putative polyketide biogenesis, incorporating a rare variant on the standard pathway, which involves the addition of methyl branches arising from C-2 carbons of acetate units to chain carbons that arise from C-1 of acetate units. 2010-04-27T06:11:27.426Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3495 Chemical investigation of the Western Australian marine brown alga Cystophora harveyi resulted in the isolation of the new linearly fused 6,6,5-tricyclic compound pycnanthuquinone C (1), in addition to four previously reported geranyltoluquinol derivatives. Structures were elucidated by interpretation of spectrometric data. Compounds with the same cyclic skeleton as 1 have been reported to be useful drug leads for the treatment of type 2 diabetes, while compounds 4 and 7 are known constituents of Chinese medicinal herbs. A biosynthetic scheme encompassing all of the geranyltoluquinol derivatives isolated from C. harveyi is proposed. 2010-04-27T05:30:29.601Z ]]>