Phenanthrene Derivatives from Asarum heterotropoides Showed Excellent Antibacterial Activity against Phytopathogenic Bacteria

Abstract

Asarum heterotropoides extracts showed strong antibacterial activity against selected phytopathogenic bacteria. Bioguided isolation was conducted to obtain 11 phenanthrene derivatives (1–11), 4 phenylpropanoids (12–15), a flavonoid (16), and a steroid (17), including a new phenanthrene derivative (1). In vitro bioassay results showed that phenanthrene derivatives are the main active components of A. heterotropoides extracts. The new compound aristoloxazine C (1) was found to exhibit outstanding antibacterial activity against Ralstonia solanacearum, Xanthomonas oryzae, Erwinia carolovora, Pseudomonas syringae, and Xanthomonas axonopodis, with MIC values of 0.05, 2.5, 2.5, 5, and 6.25 μg/mL, respectively. These values were significantly higher than that of the positive control, streptomycin sulfate. Aristoloxazine C (1) also demonstrated an excellent control effect on tobacco bacterial wilt. Physiological and biochemical experiments combined with electron microscopy showed that the antibacterial activity of aristoloxazine C (1) was primarily related to the destruction of the bacterial cell wall structure. Thus, aristoloxazine C (1) may have the potential to be used as a template for the development of new bactericides or as a probe for the discovery of new antimicrobial targets.

Identification of Antibacterial Components and Modes in the Methanol-Phase Extract from a Herbal Plant Potentilla kleiniana Wight et Arn

“…Highly concentrated sugar solutions, such as the D-maltose identified in this study, are known to be effective antimicrobial agents [ 32 ]. Previous research has indicated that the antibacterial activity of phenanthrenes and derivatives, such as the oxymorphone identified in this study, was primarily related to the destruction of the bacterial cell wall structure [ 33 ]. Plant extracts contain a large number of bioactive compounds, mainly polyphenols including flavonoids and phenolic compounds.…”

Identification and pathogenicity of multidrug‐resistantElizabethkingia miricolaisolated from farmed American bullfrogsRana catesbeianain China with in vitro screening of herbal antimicrobial agents

“…Herbal plants are a rich source of medicinal compounds and natural antimicrobial substances (Sher 2009; Zhu 2020). Some Chinese herbs, such as the mum Chrysanthemum morifolium , Baikal skullcap Scutellaria baicalensis , butterfly needle Bidens alba , C. sappan , and R. chinensis , have strong antibacterial effects against Staphylococcus aureus , S. agalactiae , A. hydrophila , Vibrio alginolyticus , and other common pathogens in food and aquaculture (Srinivasan et al 2012; Han and Bhat 2014; Guo et al 2019; Ding et al 2021; Fan et al 2021; Dhakal et al 2022; Huang et al 2022). In this study, we evaluated the in vitro antibacterial activity of 60 herbal ethanol extracts using agar disk diffusion and broth dilution assays.…”

Antibacterial Metabolites from Kiwi Endophytic Fungus Fusarium tricinctum, a Potential Biocontrol Strain for Kiwi Canker Disease

“…The influence of the most active compound on the growth of the bacteria (Psa) was assessed using a modified version of the method developed by Zeng. , Psa were diluted with a nutrient broth, and the final count was approximately 1 × 10 7 CFU/mL. The compound was first dissolved in dimethyl sulfoxide (DMSO) and diluted with sterile water, then added into the broth culture to yield concentrations of 1×, 2×, and 3× MIC.…”

“…The relative electrical conductivity was used to express the cell membrane permeability and was determined according to the method reported by Diao. , After culturing for 10 h at 37 °C, bacteria were collected by centrifugation for 6 min at 3000 rpm. The cells were washed with 5% glucose solution until the conductivity was near to that of 5% glucose.…”