Bioactive sesquiterpenes from an endophytic fungus Bipolaris sorokiniana isolated from a popular medicinal plant Costus speciosus

M Mallique Qader,N Savitri Kumar,Lalith Jayasinghe,Hiroshi Araya,Yoshinori Fujimoto

doi:10.1080/21501203.2016.1269844

M Mallique Qader, N Savitri Kumar + Show 3 more

Open Access

https://doi.org/10.1080/21501203.2016.1269844

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Journal: Mycology	Publication Date: Jan 2, 2017
Citations: 24	License type: open-access

Affiliation: National Institute of Fundamental Studies, Meiji (Japan)

Abstract

ABSTRACTBipolaris sorokiniana, a fungal endophyte, was isolated from the leaves of Costus speciosus, a popular medicinal plant used to control diabetes. Fermentation of the fungus in potato dextrose broth and chromatographic purification of the ethyl acetate (EtOAc) extracts of the culture broth and mycelium yielded two rare sesquiterpenes helminthosporal acid (1) and helminthosporol (2), together with ergosterol. Compounds 1 and 2 showed a strong phytotoxic effect on lettuce seed germination and toxicity against brine shrimps. Compound 1 also showed antifungal activity. Complete assignments of 1H and 13C NMR data of compound 1 are described for the first time.

Highlights

Endophytes are microorganisms that live in the intercellular spaces of stems, petioles, roots and leaves of plants causing no discernible manifestation of their presence and have typically gone unnoticed (Strobel and Long 1997)
In a continuation of our studies on the search for bioactive compounds from Sri Lankan flora, secondary metabolites produced by an endophytic fungus Bipolaris sorokiniana (Class: Ascomycetes & Order: Pleosporales) isolated from the leaves of Costus speciosus of the family Costaceae have been investigated
An endophytic fungus isolated from the leaves of C. speciosus was identified as B. sorokiniana

Summary

Introduction

Endophytes are microorganisms that live in the intercellular spaces of stems, petioles, roots and leaves of plants causing no discernible manifestation of their presence and have typically gone unnoticed (Strobel and Long 1997). It is well documented that endophytic fungi are capable of producing bioactive secondary metabolites. The first discovery of endophytic fungi was recorded as far back as 1904 (Freemann 1904). In a continuation of our studies on the search for bioactive compounds from Sri Lankan flora, secondary metabolites produced by an endophytic fungus Bipolaris sorokiniana (Class: Ascomycetes & Order: Pleosporales) isolated from the leaves of Costus speciosus of the family Costaceae have been investigated. C. speciosus is a widely used medicinal plant in Sri Lanka and India especially due to its antidiabetic properties and for its ability to cure various diseases (Pawar and Pawar 2014)

General

Isolation and identification of the endophytic fungus

Results and discussion