53 research outputs found
Calculations Predict That Carbon Tunneling Allows the Degenerate Cope Rearrangement of Semibullvalene to Occur Rapidly at Cryogenic Temperatures
Article on calculations predicting that carbon tunneling allows the degenerate cope rearrangement of semibullvalene to occur rapidly at cryogenic temperatures
Polyyne Hybrid Compounds from Notopterygium incisum with Peroxisome Proliferator-Activated Receptor Gamma Agonistic Effects
[Image: see text] In the search for peroxisome proliferator-activated receptor gamma (PPARγ) active constituents from the roots and rhizomes of Notopterygium incisum, 11 new polyacetylene derivatives (1–11) were isolated. Their structures were elucidated by NMR and HRESIMS as new polyyne hybrid molecules of falcarindiol with sesquiterpenoid or phenylpropanoid moieties, named notoethers A–H (1–8) and notoincisols A–C (9–11), respectively. Notoincisol B (10) and notoincisol C (11) represent two new carbon skeletons. When tested for PPARγ activation in a luciferase reporter assay with HEK-293 cells, notoethers A–C (1–3), notoincisol A (9), and notoincisol B (10) showed promising agonistic activity (EC(50) values of 1.7 to 2.3 μM). In addition, notoincisol A (9) exhibited inhibitory activity on NO production of stimulated RAW 264.7 macrophages
Ab initio investigation of dihydrogen transfer from cis-1,2-diazene. [Erratum to document cited in CA116(19):193471z]
IR spectral study of the vacuum pyrolysis of 2,3-dimethyl-and 2,3,7,8-tetramethyl-5-germaspiro[4.4]nona-2,7-dienes as possible sources of 3,4-dimethylcyclopentene-3-germylene
^(15)N NMR Spectrum of a 1,1-Diazene. N-(2,2,6,6-Tetramethylpiperidyl)nitrene
The low-temperature ^(15)N NMR spectrum of the 1,1-diazene, N-(2,2,6,6-tetramethylpiperidyl)nitrene (l), is reported.
The ^(15)N double- and mono-labeled 1,ldiazenes la and lb were synthesized. The nitrene and amino nitrogens of 1 have resonance in dimethyl ether at -90 ºC at 917.0 and 321.4 ppm, respectively, downfield from anhydrous ^(15)NH_3, affording a chemical shift difference of 595 ppm for the directly bonded nitrogen nuclei. The chemical shift of the ring nitrogen is consistent with an amino nitrogen whose lone pair is largely delocalized. The large downfield shift of the nitrene nitrogen is consistent with a large paramagnetic term due to a low-lying n → π^* transition
Inertial Effects on the Intramolecular Vibrational Energy Redistribution and Nonadiabatic Photoisomerization of a 2,3-Substituted 1,3-Butadiene: A Quasi-Classical CASSCF Dynamics Study
Perampanel in Parkinson disease fluctuations: a double-blind randomized trial with placebo and entacapone.
Safety and efficacy of perampanel in advanced Parkinson's disease: a randomized, placebo-controlled study.
H/vinyl conical intersections of hexatrienes related to the hula-twist photoisomerization
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