The chemical composition, antifungal, antioxidant and antimutagenicity properties of bioactive compounds from fungal endophytes associated with Thai orchids

Abstract

Some plant‐derived bioactive compounds produced by fungal endophytes have been proven to have antimicrobial and antioxidant activities. In this study, endophytic fungi were isolated from 20 orchid samples collected in northern Thailand from 12 genera of orchids. In total, 97 isolates were isolated from the leaves (44.3%), stems (40.2%) and flowers (15.5%) of the orchid samples. The antifungal activity was investigated of the endophytic isolates against the plant pathogenic fungi. The results showed that 13 endophytic isolates provided antifungal activities against Fusarium sp., Colletotrichum sp. and Curvularia sp. The endophyte CK F05‐5, which was isolated from the flower part of Dendrobium lindleyi, was chosen for further testing because it the highest level of antifungal activity against Fusarium sp. The isolate CK F05‐5 was identified as Fusarium oxysporum on the basis of its ITS sequences of 5.8 s rRNA, and phytochemical analysis revealed the presence of coumarins. The ethyl acetate extract of CK F05‐5 was examined for its total phenolic content and antioxidant activity using Folin–Ciocalteu's reagent and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay, respectively. The phenolic content was 160.51 mg of GAE/g of extract, and the free radical scavenging activity was 89.61 µg/ml at the half maximal inhibitory concentration (IC50). The antimutagenic potential of the ethyl acetate extract of CK F05‐5 against Trp‐P‐1 mutagenic substances was determined using the Ames test which revealed that the extract of CK F05‐5 at 10 mg/plate had the highest antimutagenic activity against Trp‐P‐1 (51.2%) and 39.6% for strains TA98 and TA100, respectively. The active compounds present in the acetate extract of CK F05‐5 were examined using GC‐MS analysis, which displayed the presence of gibepyrone A, pyrrolo [1, 2‐a] pyrazine‐1, 4‐dione, hexahydro‐3‐(2‐methylpropyl) and indoleacetic acid as major components. Based on the results, this endophytic fungus contains various bioactive components that have various biological activities. This useful information could help in producing potentially valuable and novel pharmaceutical products.

Bioprospecting endophytic fungi from Fusarium genus as sources of bioactive metabolites

“…For instance, using the DPPH radical scavenging assay, Hamzah et al (2018) reported the free radical scavenging potential of methanol-extract of F. lateritium endophyte of Rhizophora mucronata. Similarly, the phenolic content (160.51 mg of GAE/g of extract) and the free radical scavenging activity (IC 50 89.61 µg/mL) of ethyl acetate extract of F. oxysporum isolated from the flower part of Dendrobium lindleyi was also reported (Bungtongdee et al 2019). Likewise, the free radical scavenging activity (IC 50 482 μg/mL) of crude metabolites from endophytic F. tricinctum was reported by Vasundhara et al (2016).…”

“…According to Bungtongdee et al (2019), extract from F. oxysporum with strong antimutagenic activity was found to be composed of gibepyrone A, pyrrolo [1, 2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) and indoleacetic acid as major components. Another study by Tiwari et al (2014) reveals that as compared to 1,5-pentanediol, 2,3-pentanediol (105) isolated from F. oxysporum endophyte of Curcuma amada was found to improve antiaging properties against Caenorhabditis elegans.…”

The Potential of Rhizoctonia-Like Fungi for the Biological Protection of Cereals against Fungal Pathogens

“…Isolates of Rh -like fungi forming a mycorrhizal symbiosis with orchids are used due to their non-pathogenic action for biological protection of plants against their phylogenetically related representatives, which cause significant economic losses [ 18 , 19 ]. Orchid tissues contain a wide range of fungi that grow endophytically, which have protective effects against plant pathogens [ 20 ].…”

Antibacterial activity of Cordyline fruticosa leaf extracts and its endophytic fungi extracts

“…Endophytic fungi obtain nutrients, protection, and growing sites from host plants. Several endophytic fungal species have been reported to produce antibacterial, antifungal, antiviral, anti-inflammatory, and antitumor bioactive compounds that can protect host plants (Hussain et al 2014;Bungtongdee et al 2018;Praptiwi et al 2018;Ding et al 2019).…”