Discovery of anti-microbial and anti-tubercular molecules from Fusarium solani : an endophyte of Glycyrrhiza glabra

Abstract

Aims Glycyrrhiza glabra is a high‐value medicinal plant thriving in biodiversity rich Kashmir Himalaya. The present study was designed to explore the fungal endophytes from G. glabra as a source of bioactive molecules. Methods and Results The extracts prepared from the isolated endophytes were evaluated for anti‐microbial activities using broth micro‐dilution assay. The endophytic strain coded as A2 exhibiting promising anti‐bacterial as well as anti‐tuberculosis activity was identified as Fusarium solani by ITS‐5.8S ribosomal gene sequencing technique. This strain was subjected to large‐scale fermentation followed by isolation of its bioactive compounds using column chromatography. From the results of spectral data analysis and comparison with literature, the molecules were identified as 3,6,9‐trihydroxy‐7‐methoxy‐4,4‐dimethyl‐3,4‐dihydro‐1H‐benzo[g]isochromene‐5,10‐dione (1), fusarubin (2), 3‐O‐methylfusarubin (3) and javanicin (4). Compound 1 is reported for the first time from this strain. All the four compounds inhibited the growth of various tested bacterial strains with MIC values in the range of <1 to 256 μg ml−1. Fusarubin showed good activity against Mycobacterium tuberculosis strain H37Rv with MIC value of 8 μg ml−1, whereas compounds 1, 3 and 4 exhibited moderate activity with MIC values of 256, 64, 32 μg ml−1, respectively. Conclusions To the best of our knowledge, this is the first study that reports significant anti‐tuberculosis potential of bioactive molecules from endophytic F. solani evaluated against the virulent strain of M. tuberculosis. This study sets background towards their synthetic intervention for activity enhancement experiments in anti‐microbial drug discovery programme. Significance and Impact of the Study Due to the chemoprofile variation of same endophyte with respect to source plant and ecoregions, further studies are required to explore endophytes of medicinal plants of all unusual biodiversity rich ecoregions for important and or novel bioactive molecules.

Chemoprofile and functional diversity of fungal and bacterial endophytes and role of ecofactors - A review

“…This may support the observation that why a species of endophyte can synthesise a bioactive compound in one plant but is unable to do so when isolated from another host species [12]. This fact is supported by various investigations on many endophytic species like Fusarium, Colletotrichum, Alternaria, Aspergillus, Emericella, Penicillium, Pestalotiopsis, Xylaria, Bacillus, Streptomyces, and some others [2,6,27,[45][46][47][48][49][50][51][52][53][54][55][56][57][58]. In these studies, researchers have reported different important molecules from the same endophyte while isolating it from host plants of different ecoregions.…”

Isolation of Unstable Isomers of Lucilactaene and Evaluation of Anti-Inflammatory Activity of Secondary Metabolites Produced by the Endophytic Fungus Fusarium sp. QF001 from the Roots of Scutellaria baicalensis

“…Similarly, the expression of pro-inflammatory cytokines such as TNF-α and IL-6 was suppressed after treatment of DEX or 1-9 on LPS-induced macrophage cells ( Figure 5). Compound 1 was previously reported as a phytotoxin, cytotoxin against human cancer cells, a anti-parasitic agent against Trichomonas vaginalis, and an anti-tuberculosis agent [20][21][22][23]. Compound 4 was known with the hepatic glucose production inhibiting activity and cytotoxicity [24].…”

Untitled

“…exhibited the only week antioxidant property 40 . It indicates that the metabolite profile of fungal endophytes is exclusively dependent on the biochemical environment of the host as well as ecological or environmental conditions 41 .…”