Crystal and molecular structure of photodegradation product of nisoldipine

Abstract

Potential and generally selective antihypertensive and antianginal activities of nisoldipine have initiated the study of its molecular structure. The single crystals, which are the potential photodegradation products, were crystallized from methanol solution of nisoldipine, which was exposed to the action of the daylight. They were assumed to be the nitrozo derivatives of nisoldipine with the melting point 151-152°C. The crystal and molecular structure was determined by the X-ray diffraction method (MoKα, λ=0.71073A). On the basis of 3858 independent reflection intensities, the structure was solved by the direct method using the program SHELXS83 and refined by the least squares method (SHELXL93) up to final R-factor R=0.0578 for 1953 reflection (F0>4σ(F0)) and 334 parameters. The molecular structure obtained was that of: isobutyl methyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydro pyridine -3,5 dicarboxylate which confirmed that we are dealing with nisoldipine, so one should not speak about the presence of any assumed photodegradation product. .

Potencijalna i u opštem slučaju selektivna antihipertenzivna i antianginozna aktivnost nizoldipina kao i njegova izuzetna fotosenzitivnost na dnevnom svetlu, inicirala je istraživanje njegove molekulske strukture kao i molekulske strukture njegovih produkata. Iz metanolnog rastvora nizoldipina izloženog dejstvu dnevne svetlosti dobijeni su kristalizacijom potencijalni produkti fotodegradacije. Pretpostavljeno je da se radi o nitrozo derivatu nizoldipina, tačke topljenja 151-152°C. Kristalna i molekulska struktura određena je metodom difrakcije rendgenskih zraka (MoKα, λ=0.71073A). Na osnovu 3858 izmerenih intenziteta refleksa rešena je molekulska struktura, direktnom metodom primenom programa SHELXS83 i utačnjena metodom najmanjih kvadrata (SHELXL93) do konačnog R-faktora R=0.0578 za 1953 refleksa (F0>4σ(F0)) i 334 parametra. Dobijena molekulska struktura: izobutil metil-2,6-dimetil-4-(2-nitrofenil)-1,4-dihidropiridin-3,5-dikarboksilat, potvrdila je da se radi o nizoldipinu i da nema osnova govoriti da kristali pripadaju nekom od pretpostavljenih produkata fotodegradacije. .