Antifungal activity of Ligusticum chuanxiong essential oil and its active composition butylidenephthalide against Sclerotium rolfsii

Abstract

BACKGROUNDPeanut stem rot caused by Sclerotium rolfsii is an epidemic disastrous soil‐borne disease. Recently, natural products tend to be safe alternative antifungal agents to combat pathogens.RESULTSThis work determined the preliminary antifungal activity of 29 essential oils against S. rolfsii and found that Ligusticum chuanxiong essential oil (LCEO) showed the best antifungal activity, with an EC50 value of 81.79 mg/L. Sixteen compositions (98.78%) were identified in LCEO by GC‐MS analysis, the major compositions were five phthalides (93.14%). Among these 5 phthalides, butylidenephthalide was the most effective compound against S. rolfsii. Butylidenephthalide not only exhibited favorable in vitro antifungal activity against the mycelial growth, sclerotia production and germination of S. rolfsi, but also presented efficient in vivo efficacy in the control of peanut stem rot. Seven days after application in greenhouse, the protective and curative efficacy of butylidenephthalide at 300 mg/L (52.02%, 44.88%) and LCEO at 1,000 mg/L (49.60%, 44.29%) against S. rolfsii were similar to that of the reference fungicide polyoxin at 300 mg/L (54.61%, 48.28%). Butylidenephthalide also significantly decreased the oxalic acid and polygalacturonase content of S. rolfsii, suggesting a decreased infection ability on plants. Results of biochemical actions indicated that butylidenephthalide did not have any effect on the cell membrane integrity and permeability but significantly decreased nutrient contents, disrupted the mitochondrial membrane, inhibited energy metabolism and induced reactive oxygen species (ROS) accumulation of S. rolfsii.CONCLUSIONOur results could provide an important reference for understanding the application potential and mechanisms of butylidenephthalide in the control of S. rolfsii.This article is protected by copyright. All rights reserved.

Design, synthesis and bioactivity of a new class of antifungal amino acid‐directed phthalide compounds

“…The in vitro antifungal activity of the compounds was evaluated using the mycelial growth rate method described by Cui et al 9 Initially, the antifungal activity of 25 amino acids with varied configurations against S. rolfsii was evaluated, and then highly active amino acids were selected to bind with phthalide to synthesize the target compounds. The target compounds demonstrating >50% inhibition activity against S. rolfsii at a concentration of 600 mg L −1 were chosen for accurate biological activity determination.…”

“…The fungicidal active components, including carvacrol, eugenol, 7 and allicin 8 can be derived from plants. According to our previous research, 9 it was found that butylidenephthalide in Chuanqiong essential oil displayed promising antifungal activity against southern blight disease in vitro [half maximal effective concentration (EC 50 ) = 15.18 mg L −1 ]. However, butylidenephthalide is known for its medicinal properties in treating cardiac arrhythmias 10 and early dementia, 11 in which substance's hazard code is Xn (Harmful), and use in the field may pose a risk to non-target organisms.…”