New Article in Steroids

Print

Structural analysis of 25-hydroxycholesterol stereoisomers differing in configuration in position 17 and 20, by three-dimensional NMR spectra

Maria Misiak, Wiktor Koźmiński, Jacek Wójcik, Rafał R. Siciński, Jerzy Wicha


The application of 3D NMR experiments and DFT calculations enabled the structure investigation of C-17 epimer of 3-(25-hydroxycholest-5-enyl) acetate is presented. The H-17 and H-20 protons features the same values of 1H chemical shift, what causes that the structure elucidation require additional resolution enabled by 3D NMR experiments. The NMR experiments and theoretical calculations allowed for: the resonance assignment (3D COSY-HMBC and 3D TOCSY-HSQC techniques), the prediction of spatial structure (3D NOESY-HSQC and 3D ROESY-HSQC experiments), and the precise measurement of heteronuclear coupling constants (3D HSQC-TOCSY spectra with E.COSY-type multiplets).

 

We use cookies to improve our website and your experience when using it. Cookies used for the essential operation of the site have already been set.

I accept cookies from this site.