Quantum chemical and nuclear magnetic resonance spectral studies on molecular properties and electronic structure of berberine and berberrubine

Abstract

The structural and electronic properties of berberine and berberrubine have been studied extensively using density functional theory (DFT) employing B3LYP exchange correlation. The geometries of these molecules have been fully optimized at the B3LYP/6-311G** level. The chemical shift of 1H and 13C resonances in NMR spectra of these molecules have been calculated using the gauge invariant atomic model (GIAO) method as implemented in Gaussian 98. One- and two-dimensional HSQC (1H-13C), HMBC (1H-13C) and ROESY (1H-1H) spectra were recorded at 500 MHz for the berberine molecule in D(2)O solution. All proton and carbon resonances were unambiguously assigned, and inter-proton distances obtained from ten observed NOE contacts. A restrained molecular dynamics (RMD) approach was used to get the optimized solution structure of berberine. The structure of berberine and berberrubine molecules was also obtained using the ROESY data available in literature. Comparison of the calculated NMR chemical shifts with the experimental values revealed that DFT methods produce very good results for both proton and carbon chemical shifts. The importance of the basis sets to the calculated NMR parameters is discussed. It has been found that calculated structure and chemical shifts in the gas phase predicted with B3LYP/6-311G** are in very good agreement with the present experimental data and the measured values reported earlier.

Physicochemical Characterization of Berberine Chloride: A Perspective in the Development of a Solution Dosage Form for Oral Delivery

“…The proton signals for berberine chloride (Fig. 1) were assigned based on a report published by Tripathi et al (30). Figure 6 demonstrates the 1 HNMR spectra of berberine chloride, HPβCD, and the drug in the presence of varying amounts of HPβCD, and Fig.…”

Pharmacokinetics in rats and tissue distribution in mouse of berberrubine by UPLC-MS/MS

“…The medicinal value of protoberberine alkaloid from root, rhizome and stem bark of the Berberis vulgaris L. plant has been well recognized from ancient times [1]. It exhibits a variety of biological and pharmacological functions such as anti-cancerous, antimicrobial [2], anti-plasmodial [3], antidiarrhoeal [4], anti-cardiovascular [5] activities.…”

Fluorescently Sensing of DNA Triplex Assembly Using an Isoquinoline Alkaloid as Selector, Stabilizer, Inducer, and Switch‐On Emitter

“…Our results provide an interesting structural insight into the selective recognition of triplex DNA with various IQAs. Protoberberine IQAs (PAL, BER, EPI, JAT, COP, WOR, and BEU) have nonplanar molecular skeletons owing to saturated ring E, whereas unsaturated ring B in the benzophenanthridine IQAs (SAN, CHE, and NIT) and the unsaturated ring E in COR cause these molecules to have planar skeletons . The results in Figure A reveal conclusively that, in respect to the skeleton conformation, the nonplanar IQAs are less efficient than the planar IQAs in stabilizing and inducing triplex assembly.…”