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A chemical study of the EtOAc extract of Nemania bipapillata (AT-05), an endophytic fungus isolated from the marine red alga Asparagopsis taxiformis - Falkenbergia stage, led to the isolation of five new botryane sesquiterpenes, including the diastereomeric pair (+)-(2R,4S,5R,8S)-(1) and (+)-(2R,4R,5R,8S)-4-deacetyl-5-hydroxy-botryenalol (2), (+)-(2R,4S,5R,8R)-4-deacetyl-botryenalol (3), one pair of diastereomeric botryane norsesquiterpenes bearing an unprecedented degraded carbon skeleton, (+)-(2R,4R,8R)-(4) and (+)-(2R,4S,8S)-(5), which were named nemenonediol A and nemenonediol B, respectively, in addition to the known 4β-acetoxy-9β,10β,15α-trihydroxyprobotrydial (6). Their structures were elucidated using 1D and 2D NMR, HRESIMS and comparison with literature data of similar known compounds. The absolute configurations of 2, 3 and 4 were deduced by comparison of experimental and calculated electronic circular dichroism (ECD) spectra, while those of 1 and 5 were assigned from vibrational circular dichroism (VCD) data. Compound 4 weakly inhibited acetylcholinesterase, whereas compound 1 inhibited both acetylcholinesterase and butyrylcholinesterase. Compounds 1, 3, 5 and 6 were tested against two carcinoma cell lines (MCF-7 and HCT-116), but showed no significant citotoxicity at tested concentrations (IC 50  > 50 µM).

The endophytic fungi Muscodor spp. produce volatile organic compounds (VOCs) which can inhibit and even kill pathogenic fungi, bacteria, and nematodes. Nine endophytic fungal strains, isolated from the shoots of gramineous plants including Arthraxon hispidus, Eleusine indica, Oplismenus undulatifolius, and Oryza granulata, were identified as Muscodor through phylogenetic analysis of the internal transcribed spacer. Through an SPSS K-means cluster analysis, the nine Muscodor strains were divided into four groups based on the antifungal activities of the VOCs produced by these fungi determined by a two-section confrontation test. The first group contains the strains Y-L-54, W-S-41, Y-S-35, W-T-27, and Y-L-56, which showed the strongest activity. The second and third groups contain W-S-35 and Y-L-43, which showed stronger and moderate activity, respectively. The fourth group contains W-S-38 and N-L-7, which were the weakest in inhibiting the tested pathogens. Thirty-five compounds and the relative amounts of VOCs were determined by SPME-GC-MS and comparison with the NIST14 mass spectrometry database and Agilent MassHunter qualitative and quantitative analyses. These 35 compounds were classified into two different categories: (a) the product of fatty acid degradation, and (b) the intermediate and final metabolite of the metabolic pathway with the precursor of mevalonic acid. SPSS clustering analysis showed that the chemical components of VOCs might be correlated with their bioactivity rather than their phylogenetic assignment and some of the identified compounds might be responsible for antifungal activity. In conclusion, new Muscodor endophytes were recorded in tropical gramineous plants and a number of strains showed remarkable bioactive properties. Therefore, they have important potential applications in the fields of plant disease control., (© 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46μmolmL -1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02μmolmL -1 , respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease., (Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)

Aims: To evaluate the phytotoxic, antifungal and antioomycete activity; and, determine the chemical composition of the volatile organic compounds (VOCs) and semi-volatile metabolites produced by the endophyte Hypoxylon anthochroum strain Blaci isolated from Bursera lancifolia., Methods and Results: Based on its macro- and micro-morphological features, the strain Blaci was identified as Nodulisporium sp.; partial analysis of its ITS1-5.8-ITS2 ribosomal gene sequence revealed the identity of the teleomorphic stage of the fungus as H. anthochroum. Phytotoxic and antimicrobial activities of VOCs, and culture medium and mycelium organic extracts from H. anthochroum Blaci were determined by simple and multiple antagonism bioassays, and gas phase and agar dilution bioassays respectively. The volatile and semi-volatile metabolites were identified by gas chromatography-mass spectrometry. VOCs from a 5-day H. anthochroum strain Blaci culture caused the inhibition of seed germination, root elongation and seedling respiration on Amaranthus hypochondriacus, Panicum miliaceum, Trifolium pratense and Medicago sativa. In addition, extracts, phenylethyl alcohol and eucalyptol main compounds present in the VOCs and extract displayed a high phytotoxic activity, inhibiting the three physiological processes on the four test plants in a concentration-dependent manner., Conclusions: The results revealed that H. anthochroum strain Blaci produces a mixture of VOCs. These VOCs showed a strong phytotoxic activity on seed germination, root elongation, and seedling respiration of four plants and slightly affected the growth of phytopathogenic fungi and oomycetes. Also, the culture medium and mycelium extracts of H. anthochroum showed a high phytotoxic activity on the four test plants and, generally, the culture medium extract was more phytotoxic than the mycelium extracts., Significance and Impact of the Study: This work firstly reports the phytotoxic activity of volatile and semi-volatile compounds produced by the endophyte H. anthochroum strain Blaci on seed germination, root elongation, and seedling respiration of four different plants; consequently, these compounds could be useful in biocontrol of weeds and plant pathogens., (Journal of Applied Microbiology © 2016 The Society for Applied Microbiology.)

For screening bilobalide (BB)-producing endophytic fungi from medicinal plant Ginkgo biloba, a total of 57 fungal isolates were isolated from the internal stem, root, leaf, and bark of the plant G. biloba. Fermentation processes using BB-producing fungi other than G. biloba may become a novel way to produce BB, which is a terpene trilactones exhibiting neuroprotective effects. In this study, a BB-producing endophytic fungal strain GZUYX13 was isolated from the leaves of G. biloba grown in the campus of Guizhou University, Guiyang city, Guizhou province, China. The strain produced BB when grown in potato dextrose liquid medium. The amount of BB produced by this endophytic fungus was quantified to be 106 μg/L via high-performance liquid chromatography (HPLC), substantially lower than that produced by the host tissue. The fungal BB which was analyzed by thin layer chromatography (TLC) and HPLC was proven to be identical to authentic BB. The strain GZUYX13 was identified as Pestalotiopsis uvicola via morphology and ITS rDNA phylogeny. To the best of our knowledge, this is the first report concerning the isolation and identification of endophytic BB-producing Pestalotiopsis spp. from the host plant, which further proved that endophytic fungi have the potential to produce bioactive compounds.

Bioassay-guided fractionation of the fermentation extract of Xylaria sp. XC-16, an endophyte from Toona sinensis led to the isolation of two new cytochalasans cytochalasin Z27, 1, and cytochalasin Z28, 2, along with three known compounds seco-cytochalasin E, 3, and cytochalasin Z18, 4, and cytochalasin E, 5. The structures of 1 and 2 were elucidated by spectroscopic and electronic circular dichroism methods. Compound 5 was shown to be potently cytotoxic against brine shrimp (LC50 = 2.79 μM), comparable to that of the positive agent toosendanin (LC50 = 4.03 μM), and also exhibited potential phytotoxic effects on Lactuca sativa and Raphanus sativus L. seedlings, which are higher than that of the positive control glyphosate. Additionally, the fungicidal effect of 2 against the phytopathogen Gibberella saubinetti was better than that of hymexazol. This is the first report of the three types of cytochalasins present in genus Xylaria. A structure-phytotoxicity activity relationship is also discussed.

A Nodulisporium species (designated Ti-13) was isolated as an endophyte from Cassia fistula. The fungus produces a spectrum of volatile organic compounds (VOCs) that includes ethanol, acetaldehyde and 1,8-cineole as major components. Initial observations of the fungal isolate suggested that reversible attenuation of the organism via removal from the host and successive transfers in pure culture resulted in a 50 % decrease in cineole production unrelated to an overall alteration in fungal growth. A compound (CPM1) was obtained from Betula pendula (silver birch) that increases the production of 1,8-cineole by an attenuated Ti-13 strain to its original level, as measured by a novel bioassay method employing a 1,8-cineole-sensitive fungus (Sclerotinia sclerotiorum). The host plant produces similar compounds possessing this activity. Bioactivity assays with structurally similar compounds such as ferulic acid and gallic acid suggested that the CPM1 does not act as a simple precursor to the biosynthesis of 1,8-cineole. NMR spectroscopy and HPLC-ES-MS indicated that the CPM1 is a para-substituted benzene with alkyl and carboxyl substituents. The VOCs of Ti-13, especially 1,8-cineole, have potential applications in the industrial, fuel and medical fields., (© 2014 The Authors.)

A Nodulisporium sp. (Hypoxylon sp.) has been isolated as an endophyte of Thelypteris angustifolia (Broadleaf Leaf Maiden Fern) in a rainforest region of Central America. It has been identified both on the basis of its morphological characteristics and by scanning electron microscopy as well as ITS sequence analysis. The endophyte produces volatile organic compounds (VOCs) that have both fuel (mycodiesel) and use for biological control of plant disease. When grown on potato dextrose agar, the organism uniquely produces a series of ketones, including acetone; 2-pentanone; 3-hexanone, 4-methyl; 3-hexanone, 2,4- dimethyl; 2-hexanone, 4-methyl, and 5-hepten, 2-one and these account for about 25% of the total VOCs. The most abundant identified VOC was 1,8 cineole, which is commonly detected in this group of organisms. Other prominent VOCs produced by this endophyte include 1-butanol, 2- methyl, and phenylethanol alcohol. Moreover, of interest was the presence of cyclohexane, propyl, which is a common ingredient of diesel fuel. Furthermore, the VOCs of this isolate of Nodulisporium sp. were selectively active against a number of plant pathogens, and upon a 24 h exposure caused death to Phytophthora palmivora, Rhizoctonia solani, and Sclerotinia sclerotiorum and 100% inhibition to Phytophthora cinnamomi with only slight to no inhibition of the other pathogens that were tested. From this work, it is becoming increasingly apparent that each isolate of this endophytic Nodulisporium spp., including the Daldina sp. and Hypoxylon spp. teleomorphs, seems to produce its own unique set of VOCs.

An endophytic Hypoxylon sp. (strain CI-4) producing a wide spectrum of volatile organic compounds (VOCs), including 1,8-cineole, 1-methyl-1,4-cyclohexadiene and cyclohexane, 1,2,4-tris(methylene), was selected as a candidate for the modulation of VOC production. This was done in order to learn if the production of these and other VOCs can be affected by using agents that may modulate the epigenetics of the fungus. Many of the VOCs made by this organism are of interest because of their high energy densities and thus the potential they might have as Mycodiesel fuels. Strain CI-4 was exposed to the epigenetic modulators suberoylanilide hydroxamic acid (SAHA, a histone deacetylase) and 5-azacytidine (AZA, a DNA methyltransferase inhibitor). After these treatments the organism displayed striking cultural changes, including variations in pigmentation, growth rates and odour, in addition to significant differences in the bioactivities of the VOCs. The resulting variants were designated CI4-B, CI4-AZA and CI4-SAHA. GC/MS analyses of the VOCs produced by the variants showed considerable variation, with the emergence of several compounds not previously observed in the wild-type, particularly an array of tentatively identified terpenes such as α-thujene, sabinene, γ-terpinene, α-terpinolene and β-selinene, in addition to several primary and secondary alkanes, alkenes, organic acids and derivatives of benzene. Proton transfer reaction mass spectroscopic analyses showed a marked increase in the ratio of ethanol (mass 47) to the total mass of all other ionizable VOCs, from ~0.6 in the untreated strain CI-4 to ~0.8 in CI-4 grown in the presence of AZA. Strain CI4-B was created by exposure of the fungus to 100 µM SAHA; upon removal of the epigenetic modulator from the culture medium, it did not revert to the wild-type phenotype. Results of this study have implications for understanding why there may be a wide range of VOCs found in various isolates of this fungus in nature.

Three new eremophilane sesquiterpenes (1-3) were isolated from the mangrove endophytic fungus Xylaria sp. BL321 together with 07H239-A (4), a known analogue of the new compounds. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. Compound 4 showed activation activity on α-glucosidase at 0.15 μM (146%), and then, 4 gradually produced inhibitory activity on α-glucosidase with increasing concentration, and the IC₅₀ value is 6.54 μM.