Antifungal Activity of Compounds Extracted from Cortex Pseudolaricis against Colletotrichum gloeosporioides

Abstract

Cortex Pseudolaricis is the root bark of Pseudolarix amabilis Rehder, found only in China, and has been widely used in folk antifungal remedies in traditional Chinese medicine. In order to find the natural antifungal agents against mango anthracnose, eight compounds, namely pseudolaric acid A (1), ethyl pseudolaric acid B (2), pseudolaric acid B (3), pseudolaric acid B-O-β-d-glucoside (4), piperonylic acid (5), propionic acid (6), 3-hydroxy-4-methoxybenzoic acid (7), and 4-(3-formyl-5-methoxyphenyl) butanoic acid (8) were isolated from the ethanol extracts of Cortex Pseudolaricis by bioassay-guided fractionation and evaluated for in vitro antifungal activity against Colletotrichum gloeosporioides Penz. Results demonstrated that all of the eight compounds inhibited the mycelial growth of C. gloeosporioides at 5 μg/mL. Among them, pseudolaric acid B and pseudolaric acid A showed the strongest inhibition with the EC50 values of 1.07 and 1.62 μg/mL, respectively. Accordingly, both Pseudolaric acid B and Pseudolaric acid A highly inhibited spore germination and germ tube elongation of C. gloeosporioides. Dipping 100 μg/mL pseudolaric acid B treatment exhibited more effective suppression on postharvest anthracnose in mango fruit when compared to the same concentration of carbendazim. Scanning electron microscopy observations revealed that pseudolaric acid B caused alterations in the hyphal morphology of C. gloeosporioides, including distortion, swelling, and collapse. Pseudolaric acid B caused the mycelial apexes to show an abnormal growth in dimensions with multiple ramifications in subapical expanded areas with irregular shape. These findings warrant further investigation into optimization of pseudolaric acid B to explore a potential antifungal agent for crop protection.

<p>Synergistic Effect of Pseudolaric Acid B with Fluconazole Against Resistant Isolates and Biofilm of <em>Candida tropicalis</em></p>

“…The morphological changes induced by PAB in C. gloeosporioides are similar to those caused by microtubule inhibitors. 28 Recent studies have suggested that the antitumor activity of PAB could be associated with its ability to inhibit cell proliferation and induce cell apoptosis related to microtubule depolymerization. 29 Microtubules, composed of α - and β-tubulin heterodimers, are responsible for a variety of biological functions including sustained shapes, the intracellular transport and the cell division.…”

Evaluating the Potential Value of Natural Product Cuminic Acid against Plant Pathogenic Fungi in Cucumber

“…Natural plant chemicals, which are the major sources of industrial and medicinal materials, including plant extracts and essential oils, have also shown potential for agricultural pest management [ 28 , 29 ]. For example, Vitex agnus-castus extract exhibited strong antifungal activity against Pythium ultimum in tomatoes under both in vitro and in vivo conditions [ 30 ]; Cortex Pseudolaricis extract exhibited potential antifungal activity against Colletotrichum gloeosporioides [ 31 ]; and the essential oil from Tetradium glabrifolium fruits showed larvicidal activity against Aedes albopictus [ 32 ]. In addition, glucosinolates, terpenoids, flavor compounds, and glucosinolates are receiving increased attention worldwide [ 33 ].…”

“…The protective activity of cuminic acid against F. oxysporum or C. lagenarium was conducted as follows [ 30 ]. One cucumber plant per pot, at a similar growth stage (three to five leaves), were irrigated with 10 mL of water, and carbendazim at 500 μg/mL or cuminic acid at 500, 1000 or 2000 μg/mL.…”

Antifungal Activity of Alpha-Mangostin against Colletotrichum gloeosporioides In Vitro and In Vivo

“…The inhibitory activity of α-mangostin against the mycelial growth of twenty plant pathogenic fungi was tested according to Zhang et al [ 37 ]. Potato dextrose agar (PDA) was used as the basal medium for all tested fungi except for Phytophthora capsici , which was tested in lima bean agar medium.…”