Fungal Endophytes: an Alternative Source for Production of Volatile Compounds from Agarwood Oil of Aquilaria subintegra
Fungal endophytes are microorganisms that are well-known for producing a diverse array of secondary metabolites. Recent studies have uncovered the bioprospecting potential of several plant endophytic fungi. Here, we demonstrate the presence of highly bioactive fungal endophytic species in Aquilaria subintegra, a fragrant wood plant collected from Thailand. Thirty-three fungal endophytic strains were isolated and further identified to genus level based on morphological characteristics. These genera included Colletotrichum, Pestalotiopsis, Fusarium, Russula, Arthrinium, Diaporthe and Cladosporium. All strains were cultured on potato dextrose broth for 30 days prior to partitioning with ethyl acetate. The volatile compounds of all extracts were investigated by gas chromatography-mass spectrometry (GC-MS). Four strains—Arthrinium sp. MFLUCC16–0042, Colletotrichum sp. MFLUCC16-0047, Colletotrichum sp. MFLUCC16-0048 and Diaporthe sp. MFLUCC16-0051—produced a broad spectrum of volatile compounds, including β-agarofuran, α-agarofuran, δ-eudesmol, oxo-agarospirol, and β-dihydro agarofuran. These compounds are especially important, because they greatly resemble those originating from the host-produced agarwood oil. Our findings demonstrate the potential of endophytic fungi to produce bioactive compounds with applications in perfumery and cosmetic industries. Antioxidant activity of all extracts was also evaluated by using 2,2-diphenyl-2-picrylhydrazyl radical scavenging assays. The ethyl acetate extract of Diaporthe sp. MFLUCC16-0051 demonstrated superior antioxidant capacity, which was comparable to that of the gallic acid standard. Our results indicate that the MFLUCC16-0051 strain is a resource of natural antioxidant with potential medicinal applications.
KeywordsAquilaria subintegra Oxo-agarospirol Agarofuran Agarwood oil Diaporthe Endophytic fungi
The authors acknowledge the financial support from Mae Fah Luang University. We are grateful to the Scientific and Technological Instruments Center and Tea Institute, Mae Fah Luang University for a PhD Research instruments and reagents. The authors wish to acknowledge Dr. Putarak Chomnunti and Dr. Saranyaphat Boonmee, of the Institute of Excellence in Fungal Research, School of Science, Mae Fah Luang University who provided assistance towards the success of this research.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
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