Antifungal activity of saponins originated from Medicago hybrida against some ornamental plant pathogens

Alicja Saniewska,Zbigniew Biały,Anna Jarecka,Marian Jurzysta

doi:10.5586/aa.2006.061

Abstract

Antifungal activity of total saponins originated from roots of Medicago hybrida (Pourret) Trautv. were evaluated in vitro against six pathogenic fungi and eight individual major saponin glycosides were tested against one of the most susceptible fungi. The total saponins showed fungitoxic effect at all investigated concentrations (0.01%, 0.05% and 0.1%) but their potency was different for individual fungi. The highest saponin concentration (0.1%) was the most effective and the inhibition of Fusarium oxysporum f. sp. callistephi, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Fusarium oxysporum f. sp. narcissi was 84.4%, 69.9%, 68.6%, 57.2%, 55.0%, respectively. While Fusarium oxysporum Schlecht., a pathogen of Muscari armeniacum, was inhibited by 9.5% only. Eight major saponin glycosides isolated from the total saponins of M. hybrida roots were tested against the mycelium growth of Botrytis tulipae. The mycelium growth of the pathogen was greatly inhibited by hederagenin 3-O-β-D-glucopyranoside and medicagenic acid 3-O-β-D-glucopyranoside. Medicagenic acid 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranoside and oleanolic acid 3-O-[β-D-glucuronopyranosyl(1→2)-α-L-galactopyranosyl]-28-O-β-D-glucopyranoside showed low fungitoxic activity. Medicagenic acid 3-O-a-D-glucopyranosyl- 28-O-β-D-glucopyranoside, hederagenin 3-O-[α-L- hamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]- 28-O-α-D-glucopyranoside and hederagenin 3-O-β-D-glucuronopyranosyl-28-O-β-D- lucopyranoside did not limit or only slightly inhibited growth of the tested pathogen. While 2β, 3β-dihydroxyolean-12 ene-23-al-28-oic acid 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranoside slightly stimulated mycelium growth of B. tulipae.

Highlights

It is commonly known that use of some fungicides can create dangers to health and to our natural environment
Antifungal activity of total saponins from roots of this species was evaluated in vitro against six fungi and eight individual major saponin glycosides were tested against Botrytis tulipae, one of the most susceptible fungus
Total saponins and saponin glycosides Total saponins and their individual glycosides were isolated from roots of M. hybrida (Pourret.) Trautv. according to the procedure described by B i a 3 y et al (2006)

Summary

Introduction

It is commonly known that use of some fungicides can create dangers to health and to our natural environment. During the last decade, more and more studies have been carried out on the possibility of using natural plant-based substances, which would be less toxic than those synthetic chemicals. Chemical structure and fungicidal activity of saponins of species such as M. sativa (L e v y et al 1989, B i a 3 y et al 1999; Martyniuk et al 1996; Saniewska et al 2001; 2003), M. arabica (Martyniuk et al 2004; B i a 3 y et al 2004; Martyniuk et al 2004; Saniewska et al 2005), M. arborea (T a v a et al 2005) and M. hybrida (B i a 3 y et al 2006) have been studied. We isolated from roots of Medicago hybrida fourteen triterpene saponins and established their structures (B i a 3 y et al 2006), but did not study their biological activities. Antifungal activity of total saponins from roots of this species was evaluated in vitro against six fungi and eight individual major saponin glycosides were tested against Botrytis tulipae, one of the most susceptible fungus

Methods

Results

Conclusion