Antimicrobial activities of secondary metabolites of endophytic fungi isolated from Catharanthus roseus

Abstract

Introduction: Recently, several endophytes have been shown to possess the potentials to synthesize novel bioactive compounds that have found use for drug discovery. We isolated endophytic fungi associated with Catharanthus roseus collected from the river banks of Amassoma in Southern Nigeria, and identified some of their bioactive secondary metabolites.
 Methods: The fungi were subjected to solid-state fermentation on rice medium and the metabolites were extracted using ethyl acetate. The fungal crude extracts were screened for antimicrobial activity and were also subjected to high-performance liquid chromatography-diode-array detection (HPLC-DAD) analysis for the identification of the bioactive compounds.
 Results: The fungal extracts showed both antibacterial and antifungal activities with minimum inhibitory concentrations ranging from 0.0625 to 1 mg/mL. The HPLC-DAD analysis of the extracts suggested the presence of citreoisocoumarin, citreoisocoumarinol, questinol, hydroxyemodin, acropyrone, methyl 2-(4-hydroxyphenyl) acetate, nigricinol, and cladosporin.
 Conclusion: The results of this study suggest that endophytic fungi associated with C. roseus could be a promising source of novel bioactive compounds with pharmaceutical and industrial importance.

Antimicrobial Activity of Metabolites of an Endophytic Fungus Isolated from the Leaves of Citrus jambhiri (Rutaceae)

“…46,47 Indole-3-acetic acid and acropyrone have also been previously reported to be present in extracts of some endophytic fungi associated with Nigerian plants. [13][14][15] These endophytes can serve as a ready source for large-scale production of these bioactive compounds for pharmaceutical or industrial applications. Nigeria's rich plant biodiversity presents an enormous platform for researchers to explore in the area of bioprospecting without the destructive harvesting of plants, but by exploring their associated endophytic organisms for pharmaceutically and industrially important molecules.…”

“…It is, therefore, necessary that steps be taken now to secure and conserve this plant biodiversity before they are completely lost. According to Akpotu et al, 14,15 the HPLC analysis has limitations as only compounds whose UV-spectra are already in the spectral library can be detected. Consequently, in the endophytic fungal extract, the undetected compounds or compounds whose spectra had no library hit may represent important or novel bioactive compounds.…”

“…The isolation of the endophytic fungus, fermentation and extraction of metabolites were carried out as described by Abba et al 12 and Akpotu et al 14 Fresh healthy leaves of C. jambhiri were collected in June 2014 from Eziama-Uli, Anambra state, Nigeria. The plant leaves were washed thoroughly in running tap water and then cut into small fragments (about 1 cm 2 ).…”

“…Tel: +2348063809147 bioactive molecules. [7][8][9][10][11][12][13][14][15] Only a few studies on the presence of endophytes in citrus plants have been performed and little is known about the microbial endophytic community of the citrus plants. [16][17][18][19] Several endophytic bacterial species have however been isolated from Citrus jambhiri.…”

Antifungal Potency of Secondary Metabolites Produced by Endophytic Bacteria against Pathogenic Fungi Pyricularia oryzae Cav.

“…However, it uses to identify the compound is limited to the availability of spectra in the database. Only compound within its spectra that available in the database that will be able to identified (Akpotu et al, 2017). In this study, the detected active compounds were unable to be identified as not listed yet in the spectra database.…”