Bioactive Secondary Metabolites from the Endophytic Fungi Alternaria sp (original) (raw)
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Journal of Natural Products, 2008
From the Egyptian medicinal plant Polygonum senegalense the fungal endophyte Alternaria sp. was isolated. Extracts of the fungus grown either in liquid culture or on solid rice media exhibited cytotoxic activity when tested in Vitro against L5178Y cells. Chromatographic separation of the extracts yielded 15 natural products, out of which seven were new compounds, with both fungal extracts differing considerably with regard to their secondary metabolites. Compounds 1, 2, 3, 6, and 7 showed cytotoxic activity with EC 50 values ranging from 1.7 to 7.8 µg/mL. When analyzed in Vitro for their inhibitory potential against 24 different protein kinases, compounds 1-3, 5-8, and 15 inhibited several of these enzymes (IC 50 values 0.22-9.8 µg/mL). Interestingly, compounds 1, 3, and 6 were also identified as constituents of an extract derived from healthy leaves of the host plant P. senegalense, thereby indicating that the production of natural products by the endophyte proceeds also under in situ conditions within the plant host.
Alternaria species: endophytic fungi as alternative sources of bioactive compounds
2018
Fungal endophytes are a rich source of functional metabolites. In particular, the different species of the genus Alternaria stand out for their arsenal of metabolites, which have roles as antimicrobial molecules, antioxidants; as well as activities against HIV or cancer or diabetes. This review will highlight on selected aspects of the fungal endophytes of Alternaria species: their widespread distribution, and the role of their metabolites with pharmaceutical or agronomical importance. The family plants associated with Alternaria species, their bioactive compounds and biological activity to date are examined.
CYTOTOXIC METABOLITES OF ALTERNARIA ALTERNATA, AN ENDOPHYTE OF THE MEDICINAL PLANT BIDENS BIPINNATA
International Journal of Pharmacy and Pharmaceutical Sciences, 2020
Objective: Endophytes are widely spread in the plant kingdom and represent a very promising source of biologically active natural products. The medicinal plant Bidens bipinnata Lin. (Asteraceae) which is known for its anti-inflammatory, antifungal and antitumor effects has been chosen for the investigation of its endophyte to search for bioactive metabolites. Methods: An endophytic Alternaria alternata species was isolated from the leaves of the plant B. bipinnata Lin. To investigate the metabolic profile of this endophytic fungus it was cultivated in several culture media as static and shaken culture. The antimicrobial and cytotoxic activities of the ethyl acetate extracts of the fungus were examined. Extracts exhibiting highest antimicrobial activities in agar diffusion assay and cytotoxicity against HeLa cancer cell line were subjected to activity-guided chromatographic fractionation for the identification of bioactive metabolites. A cytotoxic assay was performed on the isolated compounds against HeLa cancer cell lines as well as cytostatic activity tests against HUVEC and K-562 cell lines. Results: Chromatographic fractionation resulted in the isolation and identification of alternariol and tentoxin from the extract of the fungus cultivated in medium M5 while sterigmatocystin was isolated in addition to alternariol and tentoxin from the extract of the fungus grown in medium M25. Both alternariol and sterigmatocystin proved to be of moderate cytotoxicity and weak cytostatic activity with alternariol showing higher cytotoxic activity than sterigmatocystin. Highest cytotoxicity against HeLa cell lines was observed for tentoxin with a CC50 of 22.5 µg/ml. Conclusion: This study presents the isolation and identification of the bioactive metabolites alternariol, sterigmatocystin and tentoxin from the endophyte A. alternata in addition to the antifungal activity of the strain extract as well as the cytotoxic and cytostatic activities of the isolated metabolites against HeLa, HUVEC and K-562 cell lines, respectively.
Journal of Applied Microbiology, 2019
Medicinal plants associated endophytic fungi are important sources of precious bioactive compounds, contributing more than 80% of the natural drugs for various ailments. The present study was aimed at evaluating the anti-cancer activity of the crystallized compound Alternariol methyl ether (AME) against hepatocellular carcinoma both in vitro and in vivo from an endophytic fungus residing in the medicinal plant Vitex negundo. Methods and Results: The secondary metabolites from the endophytic fungus Alternaria alternata MGTMMP031 was isolated. Purification and characterization of compound was performed and the potential compound was identified as Alternariol Methyl Ether (AME). The crystal structure of AME was unambiguously confirmed by X-ray analysis. AME has been checked for its anti-bacterial and anti-cancer properties which showed its effectiveness against various bacteria and demonstrated marked anti-proliferative activity against the human hepatocellular carcinoma cells (HUH-7) both in vitro and in vivo. Mode of actions included cell cycle arrest, reducing the level of markers enzymes of liver cancer and by preventing the tumour growth.
Biomolecules, 2020
The fungus, Alternaria sonchi is considered to be a potential agent for the biocontrol of perennial sowthistle (Sonchus arvensis). A new chlorinated xanthone, methyl 8-hydroxy-3-methyl-4-chloro-9-oxo-9H-xanthene-1-carboxylate (1) and a new benzophenone derivative, 5-chloromoniliphenone (2), were isolated together with eleven structurally related compounds (3–13) from the solid culture of the fungus, which is used for the production of bioherbicidal inoculum of A. sonchi. Their structures were determined by spectroscopic (mostly by NMR and MS) methods. Alternethanoxins A and B, which were reported in A. sonchi earlier, were re-identified as moniliphenone and pinselin, respectively. The isolated compounds were tested for phytotoxic, antimicrobial, insecticidal, cytotoxic and esterase-inhibition activities. They did not demonstrate high phytotoxicity (lesions up to 2.5 mm in diameter/length at a concentration of 2 mg/mL) when tested on leaf disks/segments of perennial sowthistle (Sonch...
AMB Express, 2023
Endophytic fungi allied to plants have sparked substantial promise in discovering new bioactive compounds. In this study, propagation of the endophytic fungus Alternaria alternata HE11 obtained from Colocasia esculanta leaves led to the isolation of Ergosterol (1), β-Sitosterol (2), Ergosterol peroxide (3), in addition to three dimeric naphtho-γ-pyrones, namely Fonsecinone A (4), Asperpyrone C (5), and Asperpyrone B (6), which were isolated from genus Alternaria for the first time. Structures of the isolated compounds were established on the basis of extensive 1D and 2D NMR and, MS measurements. The ethyl acetate extract, as well as compounds 1, 3, 4 and 6 were evaluated for their antimicrobial activity using agar well-diffusion and broth microdilution assays. Molecular docking study was carried out to explore the pharmacophoric moieties that governed the binding orientation of antibacterial active compounds to multidrug efflux transporter AcrB and the ATP binding site to E. coli DNA gyrase using MOE software. Results revealed that the most active antibacterial compounds 4 and 6 bind with high affinity in the phenylalanine-rich cage and are surrounded with other hydrophobic residues. The antiproliferative activity of all isolated compounds was in vitro evaluated using the human prostatic adenocarcinoma cell lines DU-145, PC-3, PC-3 M, 22Rv1 and CWR-R1ca adopting MTT assay. Compound 4 was the most active against almost all tested cell lines, with IC 50 values 28.6, 21.6, 17.1 and 13.3 against PC-3, PC-3 M, 22Rv1 and CWR-R1ca cell lines, respectively. Key points • Characterization of Alternaria alternata HE11 strain from Colocasia esculenta leaves • First isolation of three dimeric naphtho-γ-pyrones from genus Alternaria • Fonsecinone A and Asperpyrone B showed significant anti-prostate cancer and antibacterial activity, respectively
Efficacy of Alternaria alternate NMK1 Secondary Metabolites against some Seed-borne Fungi
Egyptian Journal of Botany, 2020
Egyptian Journal of Botany http://ejbo.journals.ekb.eg/ 37 belonging to Aspergillus and Penicillium genera are the most dominant. They include A. flavus, A. ochraceus, A. parasiticus, A. versicolor, P. verrucosum, P. chrysogenum, P. griseofulvum, P. cyclopium and P. citrinum (Aziz & Mahrous, 2004). These fungi produce mycotoxins which can be nephrotoxic, teratogenic, mutagenic, immunosuppressive and carcinogenic to a variety of organisms including humans (Groopman et al., 1988; Massey et al., 1995). Furthermore, they are responsible for feed refusal (Alshannaq & Yu, 2017). A number of strategies, involving chemical and physical methods, have been proposed for the prevention of fungal contamination of 538
The interaction of plants with microorganisms at various trophic levels is primarily for growth, development and deterrence and is intertwined in a complex network of inhabitants. Endophytes of fungal origin are widely recognized for supporting the production of host plant defence systems, new secondary metabolites, biological pest control agents, and beneficial colony-forming fungi. This study focuses on the assessment of the biological activity of the endophyte, Alternaria macrospora isolated from the leaves of Trichillia connaroides. This strain was genotyped by amplification of the internal transcribed spacer (ITS) gene region. Chemical profiling of the extract is performed by gas chromatography-mass spectrometry (GCMS), indicating the presence of functional groups by FTIR peaks. In addition, A. macrospora metabolites exhibit biological activity listed as antibacterial, antifungal, larval killing, and anticancer activities. It provides a catalogue of bioactivity that is highly r...
Diketopiperazines from Alternaria dauci
Journal of the Mexican Chemical Society, 2020
Alternaria dauci is the causal agent of Alternaria leaf blight (ALB), a foliar disease of carrot crops (Daucus carota) around the world. In terms of phytotoxic metabolites production, A. dauci has received limited attention. Previous studies carried out on the secondary metabolites involved in the pathogenicity of this fungus have only reported the isolation of a ubiquitous non-selective phytotoxin known as zinniol. Because of this, the aim of this research is directed towards the isolation and identification of secondary metabolites involved in the plant-pathogen interaction process. A. dauci was cultured in the Czapek-Dox medium, and the culture filtrate was extracted with ethyl acetate. The leaf-spot assay of fractions resulting from the partition process showed a phytotoxic effect in the ethyl acetate fraction. The chromatographic separation of ethyl acetate fraction allowed the isolation of seven diketopiperazines, identified as cyclo-(pro-val) (1), cyclo-(pro-leu) (2), cyclo-(pro-phe) (3), cyclo-(val-leu) (4), cyclo-(val-phe) (5), cyclo-(leu-phe) (6) and cyclo-(leu-tyr) (7). The structures of the different metabolites were established by comparing their spectroscopic (1 H NMR) and spectrometric (GC-MS) data with those reported in the literature.
Molecules
The fungal strain Alternaria alternata JS0515 was isolated from Vitex rotundifolia (beach vitex). Twelve secondary metabolites, including one new altenusin derivative (1), were isolated. The isolated metabolites included seven known altenusin derivatives (2–8), two isochromanones (9, 10), one perylenequinone (11), and one benzocycloalkanone (12). Their structures were determined via 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and computational electronic circular dichroism (ECD) analysis. Compounds 3 and 11 increased pyruvate dehydrogenase (PDH) activity in AD-293 human embryonic kidney cells and significantly inhibited PDH phosphorylation. The IC50 values of 3 and 11 were 32.58 and 27.82 μM, respectively.