TY  - JOUR
A1  - Deyou, Tsegaye
A1  - Marco, Makungu
A1  - Heydenreich, Matthias
A1  - Pan, Fangfang
A1  - Gruhonjic, Amra
A1  - Fitzpatrick, Paul A.
A1  - Koch, Andreas
A1  - Derese, Solomon
A1  - Pelletier, Jerry
A1  - Rissanen, Kari
A1  - Yenesew, Abiy
A1  - Erdelyi, Mate
T1  - Isoflavones and Rotenoids from the Leaves of Millettia oblata ssp teitensis
JF  - Journal of natural products
N2  - A new isoflavone, 8-prenylmilldrone (1), and four new rotenoids, oblarotenoids A-D (2-5), along with nine known compounds (6-14), were isolated from the CH2Cl2/CH3OH (1:1) extract of the leaves of Millettia oblata ssp. teitensis by chromatographic separation. The purified compounds were identified by NMR spectroscopic and mass spectrometric analyses, whereas the absolute configurations of the rotenoids were established on the basis of chiroptical data and in some cases by single-crystal X-ray crystallography. Maximaisoflavone J (11) and oblarotenoid C (4) showed weak activity against the human breast cancer cell line MDA-MB-231 with IC50 values of 33.3 and 93.8 mu M, respectively.
Y1  - 2017
U6  - https://doi.org/10.1021/acs.jnatprod.7b00255
SN  - 0163-3864
SN  - 1520-6025
VL  - 80
SP  - 2060
EP  - 2066
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Koch, Andreas
T1  - Identification of mesomeric substructures by through-space NMR shieldings (TSNMRS). Trimethine cyanine/merocyanine-like or aromatic pi-electron delocalization?
JF  - Tetrahedron
N2  - The spatial magnetic properties, through-space NMR shieldings (TSNMRS), of amino-substituted heteraromatic six-membered ring systems such as pyrylium/thiopyrylium analogues have been calculated using the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept and visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values were employed to quantify and visualize the existing aromaticity of the studied compounds. Due to strong conjugation of six-membered ring pi-electrons and lone pairs of the exo-cyclic amino substituents (restricted rotation about partial C,N double bonds) the interplay of still aromatic and already dominating trimethine cyanine/merocyanine-like substructures can be estimated. (C) 2017 Elsevier Ltd. All rights reserved.
KW  - Through-space NMR shieldings (TSNMRS)
KW  - GIAO
KW  - NICS
KW  - Benzenoid structures
KW  - Cyanine/merocyanine-like structures
KW  - Aromaticity
Y1  - 2017
U6  - https://doi.org/10.1016/j.tet.2017.05.062
SN  - 0040-4020
VL  - 73
SP  - 4265
EP  - 4274
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Marco, Makungu
A1  - Deyou, Tsegaye
A1  - Gruhonjic, Amra
A1  - Holleran, John
A1  - Duffy, Sandra
A1  - Heydenreich, Matthias
A1  - Firtzpatrick, Paul A.
A1  - Landberg, Goran
A1  - Koch, Andreas
A1  - Derese, Solomon
A1  - Pelletier, Jerry
A1  - Avery, Vicky M.
A1  - Erdelyi, Mate
A1  - Yenesew, Abiy
T1  - Pterocarpans and isoflavones from the root bark of Millettia micans and of Millettia dura
JF  - Phytochemistry letters
KW  - Millettia micans
KW  - Millettia dura
KW  - Pterocarpan
KW  - Isoflavone
KW  - Cytotoxicity
KW  - Plasmodium falciparum
Y1  - 2017
U6  - https://doi.org/10.1016/j.phytol.2017.07.012
SN  - 1874-3900
SN  - 1876-7486
VL  - 21
SP  - 216
EP  - 220
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Krtitschka, Angela
A1  - Krüger, Tobias
A1  - Linker, Torsten
T1  - NMR spectroscopic conformational analysis of 4-methylene-cyclohexyl pivalateThe effect of sp(2) hybridization
JF  - Magnetic resonance in chemistry
N2  - The conformational equilibrium of the axial/equatorial conformers of 4-methylene-cyclohexyl pivalate is studied by dynamic NMR spectroscopy in a methylene chloride/freon mixture. At 153K, the ring interconversion gets slow on the nuclear magnetic resonance timescale, the conformational equilibrium (-G degrees) can be examined, and the barrier to ring interconversion (G(#)) can be determined. The structural influence of sp(2) hybridization on both G degrees and G(#) of the cyclohexyl moiety can be quantified.
KW  - 4-methylene-cyclohexyl pivalate
KW  - conformational analysis
KW  - dynamic NMR spectroscopy
KW  - exo-methylene conformational effect at cyclohexane
KW  - quantum chemical calculations
Y1  - 2017
U6  - https://doi.org/10.1002/mrc.4630
SN  - 0749-1581
SN  - 1097-458X
VL  - 55
SP  - 1073
EP  - 1078
PB  - Wiley
CY  - Hoboken
ER  -