Three new glucosylceramides (GluCers) named malusides I–III (1–3) were isolated from apple (cultivars of Malus domestica) pomace (fruit material remaining after juice extraction). An unusual oxo/hydroxy group pattern within the sphingadienine (d18:2) type sphingoid base was observed. All compounds contained the same α-hydroxylated fatty acid (h16:0) and a β-D-glucose moiety. Their structures were assigned on the basis of one- and two-dimensional (1D and 2D) nuclear magnetic resonance (NMR) spectroscopic analyses and mass spectrometry (MS) measurements.
Publications
Thuy, T. T.; Anh, N. T. H.; Sung, T. V.; Dan, T. K.; Chinh, N. B.; Quang, N.; Franke, K.; Arnold, N.; Wessjohann, L.;Phytochemical study on the plants of the antidrug medication heantos 4: Part 4. Phthalides, fatty acids, oligosaccharide esters and miscellaneous compoundsVietnam J. Chem.51546-550(2013)
Thuy, T. T.; Anh, N. H.; Sung, T. V.; Dan, T. K.; Chinh, N. B.; Quang, N.; Franke, K.; Arnold, N.; Wessjohann, L.;Phytochemical study on the plants of the antidrug medication heantos 4: Part 1. Alkaloids and other nitrogen containing compoundsVietnam J. Chem.51185-189(2013)
Anh, N. T. H.; Thuy, T. T.; Sung, T. V.; Dan, T. K.; Chinh, N. B.; Quang, N.; Franke, K.; Arnold, N.; Wessjohann, L.;Phytochemical study on the plants of the antidrug medication heantos 4: Part 3. Homoisoflavonoid, flavonoid and phenolic compoundsVietnam J. Chem.51358-362(2013)
Anh, N. T. H.; Thuy, T. T.; Sung, T. V.; Dan, T. K.; Chinh, N. B.; Quang, N.; Franke, K.; Arnold, N.; Wessjohann, L.;Phytochemical study on the plants of the antidrug medication heantos 4: Part 2. Terpenoid- and steroid compoundsVietnam J. Chem.51190-194(2013)
Khamko, V. A.; Dien, P. H.; Schmidt, J.; Quang, D. N.;Cytotoxic and antimicrobial constituents from the roots of Stemona cochinchinesis in LaosVietnam J. Chem.50203-206(2012)
Three new pyridine alkaloids were detected in the pygidial glands of some Stenus species. The chemotaxonomic significance of the occurrence of these alkaloids and stenusine in different Stenus species is discussed. The antimicrobial properties of (Z)- and (E)-3-(2- methyl-1-butenyl)-pyridine and the deterrent activities of stenusine and norstenusine were investigated.
The complex pigment pattern of fly agaric (Amanita muscaria) cap skins has been studied by LC-DAD and mass spectrometry. Among the betaxanthins the corresponding derivatives of serine, threonine, ethanolamine, alanine, Dopa, phenylalanine and tryptophan are reported for the first time to contribute to the pigment pattern of fly agarics. Betalamic acid, the chromophoric precursor of betaxanthins and betacyanins, muscaflavin and seco-dopas were also detected. Furthermore, the red-purple muscapurpurin and the red muscarubrin were tentatively assigned while further six betacyanin-like components could not be structurally allocated. Stability studies indicated a high susceptibility of pigment extracts to degradation which led to rapid colour loss thus rendering a complete characterization of betacyaninlike compounds impossible at present. Taking into account these difficulties the presented results may be a starting point for a comprehensive characterization of the pigment composition of fly agarics.
Publications
Ninh, P. T.; Anh, N. T. H.; Sung, T. V.; Wessjohann, L.;Studies on chemical constituents of the roots of Polygala sp.: II - Further phenylpropanoide sucrose estersVietnam J. Chem.45518-522(2007)
Anh, N. T. H.; Sung, T. V.; Arnold, N.; Wessjohann, L.;Chemical constituents of Zizyphus sativa Gaertn fruits. Part III - AlkaloidsVietnam J. Chem.45237-240(2007)
Two alkaloids have been isolated from Z. sativa fruits besides butane-2,3-diol and glycerol. The structures of alkaloids were established as stepharine and 1,2-dimethoxy,5,6,6a,7-tetrahydro-4H-dibenzo-quinoline by using MS, NMR spectroscopic data and by comparison with reported data.