Conformational Analysis Of A New Cytochalasin Using Molecular Mechanics And Nuclear Magnetic Resonance Spectroscopic Data

This projeot uses moleoular mechanics teohniques with thernaid of NMR data to determine low-energy oonformations (threedimensionalrnstructures) of a novel cytochalasin isolated fromrnfungus XYlaria Obovota[lj. Although the two-dimensionalrnstruoture for this substituted hydrogenated isoindole unitrnfused to an II-membered ring has been postulated, no study ofrnthe three-dimensional struoture has been made.rnMolecular mecanics teohniques, the force field equations,rnand conformational searching algorithms: the stoohastic searchrn(random search method) on cartesian and internal coordinatesrnhave been applied. A total of 22 conformations were generatedrnwithin 10 kcal/mol to the global minimum. The calculated protonrncoupling constants, averaged over the first six lowest-energyrnconformations, were compared with the experimental values. Therngeometry parameters, the calculated coupling constants, thernstructure of the isoindole unit, the macrocycle and overallrnstructure of the cytochalasin were also compared with similarrncytochalasins whose struotures were determined from x-ray andrnrelated experimental techniques. Comparison of the calculatedrncoupling constants and the various torsion angles for thisrnnovel fungal cytochalasin revealed similarity in thernconformations of the structures generated from the analysis andrnthose determined experimentally.

Get Full Work

Report copyright infringement or plagiarism