Fast Isolation of Flavonoids from the Endemic Species Nolana ramosissima I.M. Johnst and Its Endothelium-Independent Relaxation Effect in Rat Aorta.

Jorge Bórquez,Mario J. Simirgiotis,Javier Palacios,Alejandra Bravo,Adrián Paredes,Fredi Cifuentes,Claudio Parra

doi:10.3390/molecules25030520

Abstract

The infusion of the desertic plant Nolana ramosissima I.M. Johnst showed vascular smooth muscle relaxation in rat aorta and the presence of several phenolic compounds, which were detected by high resolution UHPLC-Orbitrap-HESI-MS. In addition, five flavonoids were rapidly isolated from a methanolic extract using high-performance counter-current chromatography (HPCCC). The N. ramosissima extract showed endothelium-independent relaxation effect in rat aorta. Sixty-one compounds were detected in the infusion, mainly glycosylated flavonoids, flavanones and several oxylipins, suggesting that a synergistic effect between the compounds in the extracts could be responsible for the relaxation activity. Vascular activity experiments were done in isolated organ bath. In rat aorta, a nitric oxide inhibitor did not prevent the relaxation effects of the extract; however, a selective guanylyl cyclase inhibitor partially blunted this effect. The compound 5,3′-dihydroxy-4′7-dimethoxyflavone presented higher relaxation effect than 100 μg/mL of N. ramosissima extract. The extract and the isolated metabolites from N. ramosissima can show relaxation effects on rat aorta by a mechanism that is independent of the endothelium.

Highlights

Nolana species (Solanaceae) are one of the most important genera of the Atacama Desert represented by about 85 species and subspecies [1,2]
Several compounds were identified as flavanones (Figures 3 and 4) and among them, some tentatively identified as naringenin derivatives [25]
The log half-maximal inhibitor concentration (Log IC50 ) of ODQ was significantly (p < 0.05) different in the presence of extract versus control (Table 1). These findings suggest that N. ramosissima produced relaxation in intact and endothelium-denuded rat aorta when they were exposed to cumulative concentrations of the extract

Summary

Introduction

Nolana species (Solanaceae) are one of the most important genera of the Atacama Desert represented by about 85 species and subspecies [1,2]. A few species of Nolana were investigated regarding the chemical constituents by High-Resolution Liquid Chromatography-Mass Spectrometry (HPLC-MS). Mostly labdane diterpenoids were reported until now in Nolanas. From Nolana elegans (Phil.) Reiche, new labdane diterpenoids were reported long time ago [3], and two labdanes were reported from Nolana rostrate (Lindl.) Miers ex Dunal [4] and two more labdanes were reported from. Nolana filifolia I.M. Johnst [5]. From Nolana coelestis Miers ex Dunal four sesquiterpenoids

Methods

Results

Conclusion