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91.
92.
Ni-phosphine complexes were used as catalysts for the cycloaddition of various ketenes and diynes. In general, 2,4-cyclohexadienones were formed instead of products arising from decarbonylation of the ketenes. 相似文献
93.
Felix Blei Sebastian Dörner Janis Fricke Dr. Florian Baldeweg Felix Trottmann Dr. Anna Komor Dr. Florian Meyer Prof. Dr. Christian Hertweck Prof. Dr. Dirk Hoffmeister 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(3):729-734
The psychotropic effects of Psilocybe “magic” mushrooms are caused by the l -tryptophan-derived alkaloid psilocybin. Despite their significance, the secondary metabolome of these fungi is poorly understood in general. Our analysis of four Psilocybe species identified harmane, harmine, and a range of other l -tryptophan-derived β-carbolines as their natural products, which was confirmed by 1D and 2D NMR spectroscopy. Stable-isotope labeling with 13C11-l -tryptophan verified the β-carbolines as biosynthetic products of these fungi. In addition, MALDI-MS imaging showed that β-carbolines accumulate toward the hyphal apices. As potent inhibitors of monoamine oxidases, β-carbolines are neuroactive compounds and interfere with psilocybin degradation. Therefore, our findings represent an unprecedented scenario of natural product pathways that diverge from the same building block and produce dissimilar compounds, yet contribute directly or indirectly to the same pharmacological effects. 相似文献
94.
Janis Fricke Dr. Robert Kargbo Dr. Lars Regestein Claudius Lenz Dr. Gundela Peschel Prof. Dr. Miriam A. Rosenbaum Dr. Alexander Sherwood Prof. Dr. Dirk Hoffmeister 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(37):8281-8285
Psilocybin, the principal indole alkaloid of Psilocybe mushrooms, is currently undergoing clinical trials as a medication against treatment-resistant depression and major depressive disorder. The psilocybin supply for pharmaceutical purposes is met by synthetic chemistry. We replaced the problematic phosphorylation step during synthesis with the mushroom kinase PsiK. This enzyme was biochemically characterized and used to produce one gram of psilocybin from psilocin within 20 minutes. We also describe a pilot-scale protocol for recombinant PsiK that yielded 150 mg enzyme in active and soluble form. Our work consolidates the simplicity of tryptamine chemistry with the specificity and selectivity of enzymatic catalysis and helps provide access to an important drug at potentially reasonable cost. 相似文献
95.
Intensified diode array detectors were used to obtain triboluminescence spectra. For sucrose, uranyl nitrate and triethylammonium tetrakis(dibenzoylmethide)europate, the signal-to-noise ratios of the spectra were one to three orders of magnitude better than those previously reported. The triboluminescence spectra of menthol and 9-anthrylmethanol were determined for the first time. The triboluminescence spectra of menthol and sucrose have intensities which correspond quite well to that of the nitrogen discharge, indicating that charge separation rather than a radiationaless transition is responsible for the triboluminescence in these compounds. 相似文献
96.
97.
McDonagh AM Zareie HM Ford MJ Barton CS Ginic-Markovic M Matisons JG 《Journal of the American Chemical Society》2007,129(12):3533-3538
Exposure of a Au(111) surface to ethynylbenzene in solution leads to the formation of a bound monolayer. A chemisorption process occurs to give a stable layer consisting of oxygen-containing hydrocarbon species. Ethynylbenzene itself does not oxidize under the deposition conditions indicating that the gold surface facilitates the oxidation process. Calculations show that ethynylbenzene and its oxidation products phenylacetic acid and phenyloxirane have positive binding energies to the gold surface. 1,4-Diethynylbenzene also binds to Au(111) and anchors gold nanoparticles deposited from solution to form dense, semiregular arrays. 相似文献
98.
99.
Tony J Aitchison Milena Ginic‐Markovic Martin Saunders Peter Fredericks Suresh Valiyaveettil Janis G. Matisons George P. Simon 《Journal of polymer science. Part A, Polymer chemistry》2011,49(19):4283-4291
The synthesis and characterization of multiwalled carbon nanotube (MWCNT) polymer brushes produced by activators regenerated by electron transfer (ARGET) in atom‐transfer radical polymerization (ATRP) was discussed. The polymer brushes were synthesized by esterification of the MWCNT carboxylic acid groups with hydroxyethyl‐2‐bromoisobutyrate and subsequently used in ARGET ATRP. This created a well defined living polymer brush carbon nanotube of comparatively low polydispersity and a polymer layer 10 nm thick. As, ARGET ATRP uses only minute concentrations of copper (II) catalyst, and is less sensitive to air compared to other living polymerization techniques, this process is a more industry‐compatible route for the commercialization of such materials. The structural and chemical properties were explored by a range of techniques including high resolution transmission electron microscopy, gel permeation chromatography, elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, the polymer brush nanotubes were explored for their potential use in films and as fillers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
100.
Janis Fricke Claudius Lenz Jonas Wick Felix Blei Prof. Dr. Dirk Hoffmeister 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(4):897-903
The fungal genus Psilocybe and other genera comprise numerous mushroom species that biosynthesize psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine). It represents the prodrug to its dephosphorylated psychotropic analogue, psilocin. The colloquial term “magic mushrooms” for these fungi alludes to their hallucinogenic effects and to their use as recreational drugs. However, clinical trials have recognized psilocybin as a valuable candidate to be developed into a medication against depression and anxiety. We here highlight its recently elucidated biosynthesis, the concurrently developed concept of enzymatic in vitro and heterologous in vivo production, along with previous synthetic routes. The prospect of psilocybin as a promising therapeutic may entail an increased demand, which can be met by biotechnological production. Therefore, we also briefly touch on psilocybin's therapeutic relevance and pharmacology. 相似文献