Chemical composition, and in vitro antibacterial and antifungal activity of an alkaloid extract from Crinum angustum Steud.

Abstract

In the search for novel antibacterial agents against multidrug-resistant bacteria, an alkaloid extract obtained from whole plants of Crinum angustum Steud., containing six different groups of alkaloids, was analysed by using gas chromatography/mass spectrometry, and its in vitro activity against American Type Culture Collection bacterial strains and clinical isolates was evaluated. The antimicrobial activity of the extract was tested against nine standard strains of microorganisms and two drug-resistant clinical isolates, methicillin-resistant Staphylococcus aureus and carbapenemase-producing Klebsiella pneumoniae. The extract exhibited a significant activity against six of the examined strains of microorganisms. Antibacterial activity was more pronounced on Gram-positive bacteria than on Gram-negative bacteria, and IC₅₀ values ranged from 156 to 625 μg/mL. Mycostatic activity against Candida albicans was also found, with an IC₅₀ of 78 μg/mL after 48 h of incubation . Promising results were also obtained from tests carried out on both clinical isolates investigated.

Keywords::

• Crinum angustum Steud
• Amaryllidaceae
• antimicrobial activity
• alkaloids

Acknowledgement

This research was supported by the Basic Research Program FARB of Ferruccio Poli (Finanziamenti di Ateneo per la Ricerca di Base, 2013) from the University of Bologna. The authors declare no competing financial interest.

Notes

This manuscript was submitted at SIF 2013, National Congress of Società Italiana di Fitochimica (Italian Phytochemical Society), Gargnano (Italy).