Lovastatin-producing endophytic fungus isolated from a medicinal plant Solanum xanthocarpum

Lovastatin is a potent drug for lowering blood cholesterol. An endophytic fungus Phomopsis vexans was isolated from the healthy leaf tissues of Solanum xanthocarpum, a medicinal plant, and screened for lovastatin production. The fungus was identified by their characteristic cultural morphology and molecular analysis. The strain had a component with the same TLC R_f value and HPLC retention time as authentic lovastatin. The presence of lovastatin was further confirmed by FT-IR, UV, ¹H, ¹³C NMR and LC–MS analyses. The amount of lovastatin produced by this endophytic fungus was quantified to be 550 mg/L, and thus the fungus can serve as a potential material to improve the production of lovastatin.     

Optimization of Elicitation Conditions with Methyl Jasmonate and Salicylic Acid to Improve the Productivity of Withanolides in the Adventitious Root Culture of Withania somnifera (L.) Dunal

Adventitious root cultures derived from leaf derived callus of Withania somnifera (L.) Dunal were treated with methyl jasmonate and salicylic acid independently. Biomass accumulation, culture age, elicitation period, and culture duration were optimized for higher withanolides production in the two best-responding varieties collected from Kolli hills (Eastern Ghats) and Cumbum (Western Ghats) of Tamil Nadu, India. Between the two elicitors, salicylic acid (SA) improved the production of major withanolides (withanolide A, withanolide B, withaferin A, and withanone) as well as minor constituents (12-deoxy withastramonolide, withanoside V, and withanoside IV) in the Kolli hills variety. Treatment of root biomass (11.70?g FW) on 30-day-old adventitious root cultures with 150???M SA for 4?h elicitor exposure period resulted in the production of 64.65?mg?g^?l dry weight (DW) withanolide A (48-fold), 33.74?mg?g^?l DW withanolide B (29-fold), 17.47?mg?g^?l DW withaferin A (20-fold), 42.88?mg?g^?l DW withanone (37-fold), 5.34?mg?g^?l DW 12-deoxy withastramonolide (nine fold), 7.23?mg?g^?l DW withanoside V (seven fold), and 9.45?mg?g^?l DW withanoside IV (nine fold) after 10?days of elicitation (40th day of culture) when compared to untreated cultures. This is the first report on the use of elicitation strategy on the significant improvement in withanolides production in the adventitious root cultures of W. somnifera.     

Gymnemagenin-producing Endophytic Fungus Isolated from a Medicinal Plant Gymnema sylvestre R.Br

Gymnema sylvestre is a plant containing the triterpenoid gymnemagenin, which is used in the pharmaceutical industry as an antidiabetic agent. The objective of this study was to determine whether endophytic fungi, isolated from G. sylvestre, produce gymnemagenin. We isolated an endophytic fungal strain from the leaves of G. sylvestre which produces gymnemagenin in the medium. The fungus was identified as Penicillium oxalicum based on morphological and molecular methods. The strain had a component with the same TLC Rf value and HPLC retention time as authentic gymnemagenin. The presence of gymnemagenin was further confirmed by FTIR, UV, and ¹H NMR analyses.     

Validated thin‐layer chromatographic method for the identification and monitoring of the effect of the extraction method on the yield and phytochemical constituents of Egyptian Withania somnifera leaves

A sensitive, reliable, simple and rapid thin‐layer chromatographic method has been developed for routine analysis of withanolide S content for the purpose of quality control assessment of chemotype III of Withania somnifera. The new method was used first to compare the accumulation of withanolide S in different parts of the plant, which was found to be the highest in the leaves extract (0.21% w/w). Second, to investigate different extraction parameters that improve the extraction efficiency of withanolides from the leaves using conventional and ultrasound‐assisted extraction methods. The extraction efficiency was expressed via total withanolide content and withanolide S content.     

A Novel Endophytic Taxol-Producing Fungus <Emphasis Type="Italic">Chaetomella raphigera</Emphasis> Isolated From a Medicinal Plant, <Emphasis Type="Italic">Terminalia arjuna</Emphasis>

Taxol is the most important member of the clinically useful natural anticancer drug. An endophytic fungus Chaetomella raphigera (strain TAC-15) was isolated from a medicinal plant Terminalia arjuna and screened for its potential in Taxol production. The fungus was identified based on the morphology of the fungal culture and the characteristics of the spores. This fungus was grown in MID liquid medium and analyzed by chromatographically and spectrometrically for the presence of Taxol. The amount of Taxol produced by this endophytic fungus was quantified by HPLC which showed that it produced 79.6 μg/L, and further confirmative analyses were done by using UV, IR, FAB mass spectroscopy, and NMR spectroscopy. Thus, the fungus can serve as a potential material for fungus engineering to improve the production of Taxol.     

Epigenetic Genome Mining of an Endophytic Fungus Leads to the Pleiotropic Biosynthesis of Natural Products

The small‐molecule biosynthetic potential of most filamentous fungi has remained largely unexplored and represents an attractive source for the discovery of new compounds. Genome sequencing of Calcarisporium arbuscula, a mushroom‐endophytic fungus, revealed 68 core genes that are involved in natural product biosynthesis. This is in sharp contrast to the predominant production of the ATPase inhibitors aurovertin B and D in the wild‐type fungus. Inactivation of a histone H3 deacetylase led to pleiotropic activation and overexpression of more than 75 % of the biosynthetic genes. Sampling of the overproduced compounds led to the isolation of ten compounds of which four contained new structures, including the cyclic peptides arbumycin and arbumelin, the diterpenoid arbuscullic acid A, and the meroterpenoid arbuscullic acid B. Such epigenetic modifications therefore provide a rapid and global approach to mine the chemical diversity of endophytic fungi.     

An endophytic fungus from Trichoderma harzianum SWUKD3.1610 that produces nigranoic acid and its analogues

The objective of this study was to determine whether endophytic fungi, isolated from Kadsura angustifolia produce nigranoic acid and its highly oxygenated derivatives. From the 426 endophytic fungi screened, Trichoderma harzianum SWUKD3.1610 was detected to have a component with the same TLC R _f value and HPLC retention time as authentic nigranoic acid. This component was further confirmed as nigranoic acid by investigating the chemical composition of the fungal extracts. Besides (1), one new triterpenoid, 7β- schinalactone C (2), and two known minor compounds were isolated and characterized by HRESIMS, 1D and 2D NMR spectroscopic methods. Our study indicates that endophytic fungus may play an important role in increasing the quality of the crude drugs from Chinese medicinal plant K. angustifolia. This study is the first to isolate, characterize, and identify schitriterpenes-producing Trichoderma spp.     

Constituents of Withania somnifera Dun—XIII : The withanolides of chemotype III

Nine new steroidal lactones of the withanolide series (withanolides E-M) have been isolated from the leaves of Withania somnifera Dun (Solanaceae) growing in the southern coastal plane of Israel. This population of W. somnifera constitutes a new chemotype and is designated as chemotype III. The following structures have been assigned to seven of the above compounds:Withanolide G, 20α-hydroxy-1-oxo-20R,22R-witha-2,5,8(14),24-tetraenolide (1); withanolide H, 20α,27-dihydroxy-1-oxo-20R,22R-witha-2,5,8(14),24-tetraenolide (2); withanolide I, 20α-hydroxy-1-oxo-20R,22R-witha-3,5,8(14),24-tetraenolide (3); withanolide J, 17α,20α-dihydroxy-1-oxo-20S,22R-witha-2,5,8(14),24-tetraenolide (4); withanolide K, 17α,20α-dihydroxy-1-oxo-20S,22R-witha-3,5,8(14),24-tetraenolide (5); withanolide L, 17α,20α-dihydroxy-1-oxo-20S,22R-witha-2,5,14,24-tetraenolide (6); withanolide M, 17α,20α-dihydroxy-1-oxo-14α,15α-epoxy-20S,22R-witha-2,5,24-trienolide (7).     

Biological activities of ophiobolin K and 6-epi-ophiobolin K produced by the endophytic fungus Aspergillus calidoustus

Endophytic fungi represent ubiquitous microbial organisms able to live in the tissues of different plants around the world and represent a prolific source of bioactive metabolites. In the present study, the endophytic fungus Aspergillus calidoustus was isolated from the medicinal plant Acanthospermum australe (Asteraceae), and identified using molecular, physiological and morphological methods. A methylene chloride crude extract of A. calidoustus has been produced and subjected to antifungal bioassay-directed fractionation which resulted in the isolation of the two bioactive compounds: ophiobolin K and 6-epi-ophiobolin K. These pure compounds displayed antifungal activity against fungal plant pathogens, protozoal activity against Trypanosoma cruzi, and cytotoxic activity against human tumoral cell lines. The results show that A. calidoustus was able to produce the antifungal and cytotoxic metabolites ophiobolin K and 6-epi-ophiobolin K, which may help the fungus to colonise and occupy the substratum as well as survive in natural environments.     

Sesquiterpenes produced by Pestalotiopsis microspora HF 12440 isolated from Artocarpus heterophyllus

Abstract

A drimane-type sesquiterpene, (+)-dendocarbin L (1) together with two bisabolane-type sesquiterpenes, (+)-sydonic acid (2) and (+)-sydowic acid (3) were isolated from the mycelium of Pestalotiopsis microspora HF 12440, an endophytic fungus from the stem of Artocarpus heterophyllus. The structures of all compounds were elucidated using spectroscopic methods and by comparison with the literature. Compound 1 was isolated from the fungi for the first time, compounds 2 and 3 were firstly obtained from this endophytic fungus. Compound 3 showed cytotoxicity (IC₅₀ 2.56?μg/mL) against murine leukemia P-388 cells.     

Protease Produced by Endophytic Fungi: A Systematic Review

The purpose of this systematic review was to identify the available literature of production, purification, and characterization of proteases by endophytic fungi. There are few complete studies that entirely exhibit the production, characterization, and purification of proteases from endophytic fungi. This study followed the PRISMA, and the search was conducted on five databases: PubMed, PMC, Science Direct, Scopus Articles, and Web of Science up until 18 May 2021, with no time or language restrictions. The methodology of the selected studies was evaluated using GRADE. Protease production, optimization, purification, and characterization were the main evaluated outcomes. Of the 5540 initially gathered studies, 15 met the inclusion criteria after a two-step selection process. Only two studies optimized the protease production using statistical design and two reported enzyme purification and characterization. The genus Penicillium and Aspergillus were the most cited among the eleven different genera of endophytic fungi evaluated in the selected articles. Six studies proved the ability of some endophytic fungi to produce fibrinolytic proteases, demonstrating that endophytic fungi can be exploited for the further production of agents used in thrombolytic therapy. However, further characterization and physicochemical studies are required to evaluate the real potential of endophytic fungi as sources of industrial enzymes.     

Biotransformation of Protoberberine Alkaloids by the Endophytic Fungus Coelomycetes AFKR-3 Isolated from Yellow Moonsheed Plant (Archangelisia Flava (L.) Merr.)

The endophytic fungus Coelomycetes AFKR-3 isolated from young stems of yellow moonshed plant (Archangelisia flava (L.) Merr.) has shown the capability to biotransform berberine into its 7-N-oxide derivative. Further investigations showed that the fungus can also biotransform the protoberberine alkaloid, palmatine into a new derivative palmatine 7-N-oxide in liquid medium of glucose-yeast extract-peptone. Berberine 7-N-oxide displayed the same antimicrobial activity against pathogenic bacteria and pathogenic fungi as berberine     

Enzymatic degradation of Lignin-Carbohydrate complex (part I)

Initial steps in an early metabolic pathway of biodegradation of lignin by white-rot fungus are very important for application of biotechnology to the utilization of biomass; for example, enzymatic pretreatment for ethanol production from plant resources and biological pulping. Lignins in woody plants exist as giant high molecular weight compounds bounded with carbohydrates, mainly hemicelluloses at middle lamella and in secondary cell wall, and show resistance against the invasion of general microorganisms other than wood-rotting fungi and also against enzymatic digestion of cellulose. We assumed that white-rot fungi first attack the lignin-carbohydrate complex (LCC) and then decompose to some degree into oligomers of lignin and hemicellulose by an unknown enzymatic reaction. The study began with a screening of the fungus, which grew well on the LCC medium. LCCs were prepared from wood meal ofPicea jezoensis that had been extracted MWL, by the method of Koshijima (1). Six fungi (2) that grew well on the media containing decayed lignin were inoculated on agar media of LCC. After 3 d cultivation, the fungiGanoderma sp. andPoria subacida showed most growth on the medium. Crude enzyme preparations were made from decayed wood meal media with each fungus. Chromatographic detection of decomposed compounds from LCC, which is soluble in hot water, by each enzyme and Meicelase fromTricoderma viride, suggest that the wood-rotting fungus may contain another enzyme able to liberate a phenolic compound from LCC besides the enzymes ofTricoderma viride.     

Chemical investigation of metabolites produced by an endophytic fungi Phialemonium curvatum from the leaves of Passiflora edulis

Phialemonium curvatum, an endophytic fungus isolated from the leaves of Passiflora edulis was cultured in potato dextrose broth (PDB) media and chromatographic separation of the EtOAc extract of the broth and mycelium led to the isolation of 4-hydroxybenzoic acid (1), 3-indole acetic acid (2), solaniol (3), uracil (4), uridine (5) and glycerol (6). Compound 2 showed a weak antifungal activity against Cladosporium cladosporioides. This is the first report of the isolation of the endophytic fungus P. curvatum from P. edulis and complete ¹³CNMR assignments of 3.     

17O-NMR-spectroscopy as a tool for stereochemical analysis — Application to a diterpene-derivative

Summary Treatment of abietic acid methylester with Hg(OAc)₂/MeOH produces a dimethoxy derivative. The determination of the configuration at C-7 of this product by means of 1D- and 2D-NMR-spectroscopic methods is described. The results are verified by application of¹⁷O-NMR spectroscopy and comparison with well-established stereochemical dependencies of¹⁷O chemical shifts.

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¹⁷O-NMR-Spectroskopie zur stereochemischen Analyse. Anwendung auf ein Diterpen-Derivat

Zusammenfassung Umsetzung von Abietinsäuremethylester mit Hg(OAc)₂/MeOH führt zu einem Dimethoxyderivat. Die Bestimmung der Konfiguration am Zentrum C-7 erfolgt durch Anwendung von 1D- und 2D-NMR-Methoden. Die Resultate konnten durch¹⁷O-NMR-Spektroskopie aufgrund der bekannten stereochemischen Verschiebungsabhängigkeit bestätigt werden.

     

A new plastic scintillation resin for single-step separation,concentration and measurement of technetium-99

Technetium is a synthetic element with no stable isotopes, produced as waste in nuclear power plants and in cyclotrons used for nuclear medicine. The element has high mobility, in the form of TcO₄⁻; its determination is therefore important for environmental protection. Technetium is found in low concentrations and therefore common methods for its analysis include long treatments in several steps and require large amounts of reagents for its purification and preconcentration. Plastic scintillation resins (PSresin) are novel materials used to separate, preconcentrate and measure radionuclides in a single step. The objective of this study is to prepare and characterise a PSresin for the preconcentration and measurement of ⁹⁹Tc. The study first evaluates the reproducibility of the production of PSresins between batches and over time; showing good reproducibility and storage stability. Next, we studied the effect of some common non-radioactive interferences, showing small influences on measurement, and radioactive interferences (³⁶Cl and ²³⁸U/²³⁴U). ³⁶Cl can be removed by a simple treatment with 0.5 M HCl and ²³⁸U/²³⁴U can be removed from the column by cleaning with a mixture of 0.1 M HNO₃ and 0.1 M HF. In the latter case, a slight change in the morphology of the PSresin caused an increase in detection efficiency. Finally, the PSresin was applied to the measurement of real spiked samples (sea water and urine) with deviations lower than 10% in all cases.     

Mn2+ alters peroxidase profiles and lignin degradation by the white-rot fungus Pleurotus ostreatus under different nutritional and growth conditions

The white-rot fungus Pleurotus ostreatus produces two types of extracellular peroxidases: manganese-dependent peroxidase (MnP) and versatile peroxidase (VP). The effect of Mn²⁺ on fungal growth, peroxidase activity profiles, and lignin degradation by P. ostreatus was studied in liquid culture and under solid-state fermentation conditions on perlite, the latter resembling the natural growth conditions of this fungus. The fungus was grown in either a defined asparagine-containing basidiomycete selective medium (BSM) or in a rich peptone medium (PM). Biomass production, as determined by respiration experiments in solid-state fermentation and liquid cultures and fungal growth on Petri dishes, was higher in the PM than in the BSM. Mn²⁺ affected biomass production only in the PM on Petri dishes. In the nonamended PM, high levels of MnP and VP activity were detected relative to the nonamended BSM. Nevertheless, a higher rate of ¹⁴C-lignin mineralization was measured in the Mn²⁺-amended BSM, as determined during the course of 47 d of fermentation. Mn²⁺ amendment of the PM increased mineralization rate to that obtained in the Mn²⁺-amended BSM. The enzyme activity profiles of MnP and VP were studied in the BSM using anion-exchange chromatography. In the nonamended BSM, only minute levels of MnP and VP were detected. On Mn²⁺ amendment, two MnP isoenzymes (B1 and B2) appeared. Isoenzyme B2 was purified and showed 100% identity with the MnP isoenzyme purified in our previous study from PM-solid-state fermentation (P6). P6 was found to be the dominant isoenzyme in terms of activity level and gene expression compared with the VP isoenzymes. Based on these results, we concluded that Mn²⁺ plays a key role in lignin degradation under different nutritional and growth conditions, since it is required for the production of MnP in P. ostreatus.     

Cryptocin, a potent tetramic acid antimycotic from the endophytic fungus Cryptosporiopsis cf. quercina

[formula: see text] The endophytic fungus Cryptosporiopsis cf. quercina produces cryptocin in culture. Among other fungi, this unique tetramic acid displays antimycotic activity against Pyricularia oryzae, the causal agent of rice blast disease. Cryptocin also possesses activity against a wide variety of plant pathogenic but not human pathogenic fungi. The fine rhomboid-like crystals of cryptocin allowed structural elucidation by X-ray crystallography. The importance of cryptocin to the symbiotic relationship of C. quercina to its hosts is briefly discussed.     

Anti-inflammatory spirobisnaphthalene natural products from a plant-derived endophytic fungus Edenia gomezpompae

Spirobisnaphthalenes comprise a relatively rare family of natural products that are normally isolated from fungi and occasionally from plants.Here we reported the discovery of seven new preussomerintype spirobisnaphthalenes,preussomerins YT1-YT7(1-7),and seven known ones(8-14),from the endophytic fungus Edenia gomezpompae,enriching the structural diversity of this family of natural products.Their structures were established by 1 D and 2 D NMR spectroscopy,HRESIMS analysis and comparison with previously reported compounds,with the absolute configurations of compounds 1 and2 being further confirmed by single-crystal X-ray diffraction using Cu Ka radiation.The antiinflammatory activities of all isolates were assessed by measuring the production of NO in LPS-induced RAW2 64.7 macrophage cells.Among them,compounds 8 and 13 exhibited potent inhibitory activities on the production of NO,with IC_(50) values of 2.61 and 1.32 μmol/L,respectively.