Identification and Biological Activity of Antifungal Saponins from Shallot (Allium cepa L. Aggregatum Group)

Abstract

The n-butanol extract of shallot basal plates and roots showed antifungal activity against plant pathogenic fungi. The purified compounds from the extract were examined for antifungal activity to determine the predominant antifungal compounds in the extract. Two major antifungal compounds purified were determined to be alliospiroside A (ALA) and alliospiroside B. ALA had prominent antifungal activity against a wide range of fungi. The products of acid hydrolysis of ALA showed a reduced antifungal activity, suggesting that the compound's sugar chain is essential for its antifungal activity. Fungal cells treated with ALA showed rapid production of reactive oxygen species. The fungicidal action of ALA was partially inhibited by a superoxide scavenger, Tiron, suggesting that superoxide anion generation in the fungal cells may be related to the compound's action. Inoculation experiments showed that ALA protected strawberry plants against Colletotrichum gloeosporioides , indicating that ALA has the potential to control anthracnose of the plant.

Diospyros cuneata Inhibition of Fusarium oxysporum: Aqueous Extract and its Encapsulation by Ionic Gelation

“…The presence of all of these compounds with the exception of saponins and other metabolites like steroids and naphthoquinones has been reported in leaves of Diospyros species reviewed by Mallavadhani et al [7]. In addition, the antifungal activity of flavonoids, triterpenoids, and saponins against crop pathogens has recently been reported [39][40][41]. Using TLC (data not shown), we found that the sample collected during the rainy season had a higher intensity of flavonoid compounds.…”

Carpolobia lutea G. Don (Polygalaceae) Inhibits Inflammation and Oxidative Stress in an Acetic Acid Induced Model of Rat Colitis

“…3 acetylated triterpene saponins were also isolated from the roots of C. alba and C. lutea [30]. Saponins, terpenoids and polyphenolic compounds found in other plants were reported to possess immunomodulatory, anti-inflammatory, antioxidant, antiparasitic, antiviral, antispasmodic, antidiabetic, antifungal, antibacterial, antihyperglycemic and cytotoxic properties [12,[31][32][33][34][35][36][37][38]. The beneficial activity of C. lutea observed in this study might be due to these chemical constituents.…”

Saponin Interactions with Model Membrane Systems – Langmuir Monolayer Studies, Hemolysis and Formation of ISCOMs

“…Antifungal activity was found for saponins extracted from Allium cepa L. (Amaryllidaceae). The main saponins with the highest antifungal activity were alliospiroside A and alliospiroside B [38]. Further saponins with antifungal activity were extracted from leaves of Solanum chrysotrichum (Solanaceae), from berries of Phytolacca tetramera (Phytolaccaceae), or from fruits of Capiscum sp.…”