DFT Calculations and ROESY NMR Data for the Diastereochemical Characterization of Cytotoxic Tetraterpenoids from the Oleoresin of Abies balsamea

Abstract

Eight non-carotenoid tetraterpenoids, abibalsamins C-J (3-10), were isolated from the oleoresin of Abies balsamea. Their chemical structures were determined based on analysis of 1D/2D NMR and MS data. The assignment of their relative configurations was accomplished using homonuclear coupling constants in tandem with ROESY data. However, the presence of two stereogenic centers on a flexible side chain complicated the characterization. In silico models and ROESY data were analyzed in order to assign relative configurations of the isolated tetraterpenoids. Abibalsamins B and H-J showed moderate cytotoxicity against human A549 lung carcinoma cells, with IC50 values ranging between 6.7 and 10 μM.

Flavonoid glycosides from Persea caerulea. Unraveling their interactions with SDS‐micelles through matrix‐assisted DOSY, PGSE, mass spectrometry, and NOESY

“…Liquid chromatography coupled to mass spectrometry (LC–MS) represents a very powerful tool for their analysis, although, as it will be seen here, some other techniques can be also used for elucidating not only their structure but also their interactions with supramolecular systems such as micelles. Very recently, Pichette and coworkers have employed rotating frame NOE spectroscopy NMR and density functional theory (DFT) calculations to ascertain the chemical structure of non‐caretonoid abibalsamins isolated from Abies balsamea, although no other techniques such as diffusion NMR and nuclear Overhauser spectroscopy (NOESY) build‐up curves were employed …”

“…Very recently, Pichette and coworkers have employed rotating frame NOE spectroscopy NMR and density functional theory (DFT) calculations to ascertain the chemical structure of noncaretonoid abibalsamins isolated from Abies balsamea, although no other techniques such as diffusion NMR and nuclear Overhauser spectroscopy (NOESY) build-up curves were employed. [16] Results and discussion Two flavonoid glycosides kaempferol-3-O-α-L-rhamnopyranoside (1) and quercetin-3-O-α-L-arabinofuranoside (2) have been isolated from the ethanolic extract of the leaves of P. caerulea for the first time. Inspired by the work of Morris and coworkers, [17] we have investigated their interactions with sodium dodecyl sulfate (SDS) micelles in binary solvent mixtures.…”

Triterpenoids

“…DFT calculations and ROESY data have been used in the stereochemical assignment of abibalsamins C 143-I 150 from the oleoresin of Abies balsamea. 48 The abibalsamins are Diels-Alder adducts of lanostane and rearranged lanostane triterpenoids with the monoterpenoid myrcene. Kadsura coccinea is the source of two interesting groups of lanostane derivatives, kadcoccinic acids A 151-J 160 (ref.…”

Geometry, tautomerism and non-covalent interactions of the drug halofuginone with the carbon-nanotube and γ-Fe2O3 nanoparticles: A DFT study

“…In this work, the tautomerism of the halofuginone drug was investigated using valuable computational methods, which are useful in theoretical investigation of chemical reactions. [12][13][14][15][16][17][18][19][24][25][26][27][28][29][30][31][32][37][38][39] The relative energies of the optimized species are gathered in Table I. As could be seen, the H1a species is the most stable tautomer of halofuginone in aqueous solution.…”

“…[9][10][11] Nowadays, DFT methods are comprehensively used in many areas of computational chemistry, such as geometry optimization, spectroscopic assignments, drug science, investigations on the kinetics and mechanism of the chemical reactions, etc. [12][13][14][15][16][17][18][19][20][21][22][23] To date, the geometry and crystal structure of halofuginone 306 KAZERI-SHANDIZ, BEYRAMABADI and MORSALI have not been determined and therefore, a comprehensive computational investigation on the properties of halofuginone is of major importance. In this work, the molecular geometry and tautomers of halofuginone were investigated using valuable DFT approaches.…”