Publications by authors named "Alfredo R Ortega"
Magn Reson Chem
June 2017
Article Synopsis
- The structure of the dimeric eudesmanolide hydroxy-bis-dihydrofarinosin (1) was determined by comparing its H and C NMR spectra with those of related compounds, including encelin (6) and hydroxy-bis-dihydroencelin (3).
- Verification of structure 1 was accomplished through single-crystal X-ray diffraction, which confirmed the stereochemistry of the hydroxy group at C-4.
- The absolute configuration of the derived diacetate 2 was established through a comparison of its experimental vibrational circular dichroism spectrum with theoretical calculations, confirming similarities with its biogenetic precursor 4 and revealing the unknown configuration of the C-4 center in compound
Article Synopsis
- Eudesmanolide farinosin, a naturally occurring compound, has been fully characterized for the first time since its isolation nearly 50 years ago.
- The initial assumptions about its stereochemistry and absolute configuration were confirmed using vibrational circular dichroism and Hooft X-ray evaluations.
- The molecular conformation of eudesmanolide is found to be quite similar in both gas and solid states.
Magn Reson Chem
October 2015
Article Synopsis
- Researchers isolated a new compound, 7,2',5'-trimethoxy-3',4'-methylenedioxyisoflavone, from the leaves of Piscidia carthagenensis, along with two known compounds using fractional solubilization.
- They distinguished methoxy group signals through selective irradiation techniques and assigned molecular structures using NMR and advanced measurement techniques like HETCOR and gHMBC.
- The study confirmed the structure of the new compound and an existing compound through single crystal X-ray diffraction, revealing polymorphism in the new compound’s solid state with no signs of atropisomerism.
