Unser 10. Leibniz Plant Biochemistry Symposium am 7. und 8. Mai war ein großer Erfolg. Thematisch ging es in diesem Jahr um neue Methoden und Forschungsansätze der Naturstoffchemie. Die exzellenten Vorträge über Wirkstoffe…
Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Mittersteiner, M.; Pereira, G. S.; Silva, Y.; Wessjohann, L. A.; Bonacorso, H. G.; Martins, M. A. P.; Zanatta, N.;Substituent-driven selective N-/O-alkylation of 4-(trihalomethyl)pyrimidin-2(1H)-ones using brominated enonesJ. Org. Chem.874590-4602(2022)DOI: 10.1021/acs.joc.1c02919
The selective N- or O-alkylation of 4-(trihalomethyl)-pyrimidin-2(1H)-ones, using 5-bromo enones/enaminones as alkylating agents, is reported. It was found that the selectivity toward the N-or O-regioisomer is driven by the substituent present at the 6-position of the pyrimidine ring, thus enabling the preparation of each isomer as the sole product, in 60−95% yields. Subsequent cyclocondensation of the enaminone moiety with nitrogen dinucleophiles led to pyrimidine−azole conjugates in 55−83% yields.
Publikation
Corrêa dos Santos, C. H.; Geraldo de Carvalho, M.; Laub, A.; Franke, K.; Wessjohann, L.;UHPLC-ESI-Orbitrap-HR-MS analysis of cyclopeptide alkaloids from Ziziphus joazeiroNat. Prod. Commun.161-13(2021)DOI: 10.1177/1934578x211054955
Ziziphus joazeiro Mart., popularly known as “juazeiro”, is a tree widely found in the northeast of Brazil. It is commonly used as an anti-inflammatory, antibacterial, antifungal, and analgesic agent. The stem extract exhibited, beside cytotoxic properties, substantial activity against the Gram-negative bacterium Allivibrio fischeri. UHPLC-ESI-Orbitrap-HR-MS analysis of the alkaloidal fraction of the crude methanolic stem extract of this species enabled the detection and putative identification of sixteen cyclopeptide alkaloids (CPAs), including four possibly new structures. According to the MS2 fragmentation analysis, from the sixteen identified CPAs, three possess a type-Ia1, one a type-Ia2, and twelve a type-Ib cyclopeptide alkaloid core. The structures of paliurine-C and -D were supported by NMR data.
Publikation
Püllmann, P.; Weissenborn, M. J.;Pilzliche Peroxygenasen: der Schlüssel zu C-H-Hydroxylierungen und mehr?BIOspektrum25572-574(2019)DOI: 10.1007/s12268-019-1090-2
Fungal peroxygenases represent an exciting new enzyme class for stereo-selective hydroxylation reactions. They are capable of the oxyfunctionalisation of a large, diverse scope of substrates including alkanes and steroids as well as the heteroatoms sulfur and nitrogen. The outstanding activities and stabilities as well as their reliance on hydrogen peroxide as co-substrate renders it a highly interesting biocatalyst.
Publikation
Anh, N. T. H.; Tuan, N. V.; Thien, D. D.; Quan, T. D.; Tam, N. T.; Lien, G. T. K.; Franke, K.; Thuy, T. T.; Sung, T. V.;Chemical Constituents of Chirita drakeiNat. Prod. Commun.12563-566(2017)DOI: 10.1177/1934578X1701200425
Chirita drakei Burtt (now accepted as Primulina drakei (B.L.Burtt) Mich.Möller & A.Weber) is growing on limestone mountain slopes of Ha Long Bay islands in Vietnam. The chemical investigation of the aerial parts of C. drakei led to the isolation and structural elucidation of two new compounds named chiridrakoside A (1) and chiridrakoside B (2) besides twelve known compounds comprising five phenylethanoid glycosides (3–7), two lignans (8, 9), a phenyl propanoid (10), an anthraquinone (11), a furan derivative (12) and two triterpenes (13, 14). All described compounds, except 4, 5 and 11, were obtained for the first time from the genera Chirita or Primulina. The cytotoxic activity of the isolated compounds was evaluated against the four human cancer cell lines KB (mouth epidermal carcinoma), HepG2 (hepatocellular carcinoma), Lu (lung carcinoma) and MCF7 (breast carcinoma). Epoxyconiferyl alcohol (10) exhibited cytotoxic activity against the tested cell lines (IC50 from 46 to 128 μM).