¹⁴N NQR spectrum of Glybenclamide (aka Glibenclamide)

The ¹⁴N nuclear quadrupole resonance (NQR) spectrum of glybenclamide has been recorded using cross relaxation Double Resonance. Glybenclamide, also known as glibenclamide or glyburide, belongs to the class of sulfonylurea drugs. It is used as antidiabetic medication solely, or combined with biguanides such as metformin, to treat Type 2 Diabetes Mellitus. Glybenclamide has three distinct nitrogen atoms, two belong to the sulfonylurea group and the third is an amide nitrogen. The ¹⁴N NQR experimental quadrupole coupling constants (χ) and asymmetry parameters (η) of glybenclamide have been compared to its calculated ab-initio and DFT values and the orientation of the principal EFG axes for each nitrogen atom has been assigned. The nitrogen atom adjacent to the sulfonyl group has the largest calculated χ, and by extension, the largest q_zz EFG component. The experimental η and χ values for the amide nitrogen atom indicate the presence of intramolecular hydrogen bonding in the molecule.

¹⁴N NQR Spectrum of Glybenclamide (aka Glibenclamide)