TY - JOUR
T1 - Structure and absolute configuration of hydroxy-bis-dihydrofarinosin from Encelia farinosa
AU - Ortega, Alfredo R.
AU - Ortiz-Pastrana, Naytzé
AU - Quijano, Leovigildo
AU - Becerra-Martínez, Elvia
AU - Olmedo-Aguirre, José O.
AU - Joseph-Nathan, Pedro
N1 - Publisher Copyright:
Copyright © 2016 John Wiley & Sons, Ltd.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - The structure of the dimeric eudesmanolide hydroxy-bis-dihydrofarinosin (1) from Encelia farinosa followed after contrasting their 1H and 13C NMR spectra with those of encelin (6), hydroxy-bis-dihydroencelin (3), and farinosin (4). Structure 1 was verified by single-crystal X-ray diffraction analysis, which further provided the stereochemistry of the hydroxy group at C-4. Comparison of the experimental vibrational circular dichroism spectrum of its derived diacetate 2 with that calculated by density functional theory provided the absolute configuration, which resulted the same as that of its biogenetic precursor 4. Evaluation of several chemical shift differences between the two eudesmanolide fragments of 1 and 3 allows also ascertaining the yet not reported absolute configuration of the C-4 stereogenic center of 3.
AB - The structure of the dimeric eudesmanolide hydroxy-bis-dihydrofarinosin (1) from Encelia farinosa followed after contrasting their 1H and 13C NMR spectra with those of encelin (6), hydroxy-bis-dihydroencelin (3), and farinosin (4). Structure 1 was verified by single-crystal X-ray diffraction analysis, which further provided the stereochemistry of the hydroxy group at C-4. Comparison of the experimental vibrational circular dichroism spectrum of its derived diacetate 2 with that calculated by density functional theory provided the absolute configuration, which resulted the same as that of its biogenetic precursor 4. Evaluation of several chemical shift differences between the two eudesmanolide fragments of 1 and 3 allows also ascertaining the yet not reported absolute configuration of the C-4 stereogenic center of 3.
KW - 750 H NMR
KW - dimeric eudesmanolides
KW - farinosin
KW - hydroxy-bis-dihydroencelin, X-ray diffraction
KW - hydroxy-bis-dihydrofarinosin, encelin
UR - http://www.scopus.com/inward/record.url?scp=85006975103&partnerID=8YFLogxK
U2 - 10.1002/mrc.4554
DO - 10.1002/mrc.4554
M3 - Artículo
SN - 0749-1581
VL - 55
SP - 530
EP - 539
JO - Magnetic Resonance in Chemistry
JF - Magnetic Resonance in Chemistry
IS - 6
ER -