Bioactive potential of secondary metabolites derived from medicinal plant endophytes

Abstract

Medicinal plants have been used as an alternative medicine to promote human health and longevity in many regions of the world since ancient times. In recent years, many novel secondary metabolites from higher fungi have been isolated and reported to provide lead compounds for new drug discovery like antimicrobial, antioxidant, and anticancer agents, etc. A total of 42 endophytic fungi were isolated from 11 different medicinal plants collected from Tamil Nadu, India. The capability of medicinal plant endophytic fungi for the production of bioactive secondary metabolites was evaluated under in vitro conditions. The most frequently isolated fungi were Alternaria sp. Fusarium sp. and mycelia sterilia. The bioactive secondary metabolites of these endophytes were obtained by liquid-liquid extraction with ethyl acetate. Among which 15 showed antimicrobial activity towards potential human pathogens such as Escherichia coli, Salmonella typhi, Proteus mirabilis, Staphylococcus aureus, and Corynebacterium diphtheriae with variable zone of inhibition. Maximum secondary metabolite production with good mycelial growth and antimicrobial activity was observed in Alternaria sp. MGTMMP031. Moreover, in-vitro antioxidant and anticancer activity were also evaluated. The crude secondary metabolite was characterized by ultraviolet spectrum (UV), infrared spectrum (FT-IR) and thin layer chromatography (TLC) with R f value of 0.35 and the bioactive secondary metabolite was identified as alternariol methyl ether. The results concluded that secondary metabolite from Alternaria sp. may represent a potential ingredient for pharmaceutical application and are worthy of future study.

In vitro and in silico antioxidant and antiproliferative activity of rhizospheric fungus Talaromyces purpureogenus isolate-ABRF2

“…We observed a differential growth inhibition pattern of gram-positive by the ethyl acetate fraction containing the compound, 3-methyl, 4-oxo-pentanoic acid. Similarly, the zone of inhibition against gram-negative bacteria, R. eutropha was observed to be similar to that reported earlier of Alternaria sp (Palanichamy et al 2018). Interestingly, antifungal activity against candida albicans was not observed in the ethyl acetate fraction.…”

Purification, crystallization and anticancer activity evaluation of the compound alternariol methyl ether from endophytic fungiAlternaria alternata

“…The secondary metabolites from A. alternata were screened and characterized for their antibacterial properties and antioxidant activity similar to our previous study (Palanichamy et al ). Here, in the present study the concentrated ethyl acetate extract of A. alternata MGTMMP031 was fractionated by standard column chromatographic technique.…”

Chemical evaluation and antibacterial activity of novel bioactive compounds from endophytic fungi in Nelumbo nucifera

“…Results showed that the highest antibacterial activity of the fungal endophytes isolate ST9.1 was performed on day 4 with an inhibition zone of 12.67 ± 0.47 mm. The activity was highest on early fermentation suggested that such metabolism could lead to an increase metabolic products ( Adebo and Medina-Meza, 2020 ) and the diversity of metabolites synthesis were produced by various metabolic pathway ( Palanichamy et al, 2018b ). Noticeably, when the incubation time was increased, the function of bioactive molecule decreased ( Fig.…”

“…Each solvent phase was collected and condensed using the rotary vacuum evaporator. The dry crude extract metabolite was obtained at 4 °C, kept at − 20◦C and 2% DMSO, respectively, for use in the future ( Palanichamy et al, 2018a ).…”