Acremonium Sp Research Articles

Acremochlorin S and other prenylated chlorophenol antimicrobial metabolites from the fungus Acremonium sp. Strain MNA-F-1

Chemical prospection for the mycelial extract of the fungus Acremonium sp. Strain MNA-F-1, derived from the inner tissue of anise roots (Pimpnella anisum L., family Apiaceae), led to the isolation and characterization of one previously undescribed natural product, acremochlorin S (1), together with five related derivatives (2–6) and an alkaloidal metabolite, ilicicolin H (7). Structure elucidation of the isolated compounds was determined through comprehensive 1D/2D NMR spectroscopic analyses and HR-ESI-MS measurements. The absolute configuration of acremochlorin S (1) was concluded based on the comparison of its experimental and calculated electronic circular dichroism (ECD) spectra implementing Time-dependent density functional theory (TDDFT). All isolated compounds were assessed for their antibacterial activity against Staphylococcus aureus, Escherichia coli and Mycobacterium tuberculosis, where several compounds revealed potent activities against tested Gram-positive strains.

A Double Therapeutic Challenge: Handling Acremonium sp. Hyalohyphomycosis and Atypical Mycobacteriosis in Tandem in a Kidney Transplant Recipient

A Double Therapeutic Challenge: Handling Acremonium sp. Hyalohyphomycosis and Atypical Mycobacteriosis in Tandem in a Kidney Transplant Recipient

Acremosides A-G, Sugar Alcohol-Conjugated Acyclic Sesquiterpenes from a Sponge-Derived Acremonium Species.

Seven new sugar alcohol-conjugated acyclic sesquiterpenes, acremosides A-G (1-7), were isolated from the cultures of the sponge-associated fungus Acremonium sp. IMB18-086 cultivated with heat-killed Pseudomonas aeruginosa. The structures were determined by comprehensive analyses of 1D and 2D NMR spectroscopic data. The relative configurations were established by J-based configuration analysis and acetonide derivatization. The absolute configurations were elucidated by the Mosher ester method and ECD calculations. The structures of acremosides E-G (5-7) featured the linear sesquiterpene skeleton with a tetrahydrofuran moiety attached to a sugar alcohol. Acremosides A (1) and C-E (3-5) showed significant inhibitory activities against hepatitis C virus (EC50 values of 4.8-8.8 μM) with no cytotoxicity (CC50 of >200 μM).

Acremonium sp. diglycosidase-aid chemical diversification: valorization of industry by-products

The fungal diglycosidase α-rhamnosyl-β-glucosidase I (αRβG I) from Acremonium sp. DSM 24697 catalyzes the glycosylation of various OH-acceptors using the citrus flavanone hesperidin. We successfully applied a one-pot biocatalysis process to synthesize 4-methylumbellipheryl rutinoside (4-MUR) and glyceryl rutinoside using a citrus peel residue as sugar donor. This residue, which contained 3.5 % [w/w] hesperidin, is the remaining of citrus processing after producing orange juice, essential oil, and peel-juice. The low-cost compound glycerol was utilized in the synthesis of glyceryl rutinoside. We implemented a simple method for the obtention of glyceryl rutinoside with 99 % yield, and its purification involving activated charcoal, which also facilitated the recovery of the by-product hesperetin through liquid-liquid extraction. This process presents a promising alternative for biorefinery operations, highlighting the valuable role of αRβG I in valorizing glycerol and agricultural by-products.Keypoints• αRβG I catalyzed the synthesis of rutinosides using a suspension of OPW as sugar donor.• The glycosylation of aliphatic polyalcohols by the αRβG I resulted in products bearing a single rutinose moiety.• αRβG I catalyzed the synthesis of glyceryl rutinoside with high glycosylation/hydrolysis selectivity (99 % yield).Graphical

New Records in Iraq and Arab Nations for some Fungi Isolated from Al-Barakia wastewater treatment plant in Al-Najaf Province

This study was conducted in 2020 in the wastewater treatment plant in Al-Barakia Najaf, where samples were taken in November from the Bioshft unit and the compact unit from the plant to know the efficiency of the plant in treatment. The process of isolation and purification was Microbiology Laboratory_ Ecology and Pollution Department - College of Science - University of Kufa. Its diagnosis was carried out at the Plant Virus Laboratory - College of Agriculture - the University of Karbala, and (19) fungal isolates isolated from wastewater treatment plants were diagnosed. These isolates were analyzed using the PCR technique and determination of the nucleotide sequences of the polymerase chain reaction products that were amplified from those isolates using ITS4 and ITS1 primers. It belonged to the fungus A. caespitosus. and isolated A flavus (7,8), T. asperellum (9-11) A.tubingensis (12), A.terrus(13), A.niger (14,15), A. alternata (16), C.sphaerospermum (17), A.oryzae (18), Acremonium sp (19), similarity rate of 100% with isolates registered with the NCBI. The results show that all the isolated fungi diagnosed in this study are recorded globally. However, they are not recorded in Iraq, and (5) isolates are not recorded in the Arab nation and Iraq, including A. tubingensis, C.sphaerospermum, A. alternate, and A.oryzae, while the isolate Acremonium sp. According to the National Center for Biotechnology Information NCBI, it is registered only in Germany under the number (AJ557731), and the similarity rate is 100% with the isolate diagnosed in this study. Keywords: wastewater; Molecular Identification; fungi; Polymerase chain reaction (PCR); DNA sequence analysis.

Two new adenopeptins B and C inhibit sphere formation of pancreatic cancer cells.

Cancer remains one of the leading causes of death worldwide, particularly pancreatic cancer being lethal because of its aggressiveness and lack of early detection methods. A factor that contributes to malignancy are cancer stem cell-like characteristics promoted by the tumor-stromal interaction. Given that fibroblast conditioned medium (CM) promotes sphere formation of cancer cells, a cancer stem cell-like characteristic, its inhibitor could be a new anticancer agent. By exploring microbial cultures as a source, we found new compounds, namely, adenopeptins B (1) and C (2), from Acremonium sp. ESF00140. 1 and 2 selectively and potently inhibited the sphere formation of pancreatic cancer cells cultured in the fibroblast CM compared with the control medium. Oxygen consumption rate (OCR) assays showed that 1 and 2 inhibit OCR in pancreatic cancer cells. Studies of similar compounds suggested mitochondrial complex V inhibition. Therefore, results of measuring the activity of human mitochondrial complex V revealed that 1 and 2 inhibited its activity. Oligomycin A, an inhibitor of mitochondrial complex V, as well as 1 and 2, strongly inhibited the sphere formation of pancreatic cancer cells cultured in fibroblast CM. The addition of 1 and 2 to pancreatic cancer cells cultured in fibroblast CM increased reactive oxygen species (ROS) production compared with that in the control medium. In pancreatic cancer cells cultured in fibroblast CM, mitochondria significantly influence sphere formation, and targeting their function with 1 and 2 might provide a new therapeutic approach for pancreatic cancer.

Chemical constituents of the marine-derived fungus Acremonium sp. AN-13

Two new compounds named 3(S)-hydroxy-1-(2,4,5-trihydroxy-3,6- dimethylphenyl)-hex-4E-en-1-one (1) and acremonilactone (2), together with nine known compounds (3–11), were isolated from the fermentation broth of Acremonium sp. associated with marine sediments collected from South China Sea. NMR and HRESIMS spectroscopic analysis elucidated the structure of two new compounds. Compound 2 had characteristic rotary gate shape skeleton with a six-membered lactone. Compounds 1 and 9 showed DPPH radical scavenging activity with inhibition rates of 96.50 and 85.95% at the concentration of 0.5 mg/ml, respectively. Moreover, compounds 4, 6 and 11 showed definite antibacterial activity against Staphylococcus aureus ATCC 6538.

Isolation and characterization of filamentous fungi capable of degrading the mycotoxin patulin.

Patulin is a toxic secondary metabolite synthesized by various fungal strains. This mycotoxin is generally toxic to microorganisms as well as mammals due to its reactivity with the important cellular antioxidant glutathione. In this study, we explored the presence of microorganisms capable of degrading patulin. Microorganisms were screened for the ability to both grow in culture medium containing patulin and reduce its concentration. Screening of 510 soil samples resulted in the isolation of two filamentous fungal strains, one of which, Acremonium sp. TUS-MM1 was characterized in detail. Liquid chromatography-mass spectrometryand nuclear magnetic resonance analyses revealed that TUS-MM1 cells degraded patulin to desoxypatulinic acid. In addition, extracellular components of strain TUS-MM1 also exhibited patulin-transforming activity. High-performance liquid chromatography analysis revealed that the extracellular components generated several products from patulin. Disc diffusion assay using Escherichia coli cells revealed that the patulin-transformation products by the extracellular components are less toxic than patulin. We also demonstrated that a thermostable, low-molecular-weight compound within the extracellular components was responsible for the patulin-transforming activity. These results suggest that strain TUS-MM1 transforms patulin into less-toxic molecules by secreting a highly reactive compound. In addition, once patulin enters the cells, strain TUS-MM1 can transform it into desoxypatulinic acid to reduce its toxicity.

Evaluating the Effectiveness of Acremonium sp. Protease as a Natural Molluscicide Agent: A Toxicological and Histological Investigation on Land Snails

Evaluating the Effectiveness of Acremonium sp. Protease as a Natural Molluscicide Agent: A Toxicological and Histological Investigation on Land Snails

Shift in fungal communities associated with Pinus sylvestris stands affected by root rot

Introduction
 Scots pine (Pinus sylvestris) covers large areas in European regions with significant economic importance to Ukrainian forest industry. Root rot caused by the wood-decay fungus Heterobasidion annosum damages both below- and above-ground parts of Scots pines. The disease progress is likely to be affected by reshaping in the forest such as soil properties, vegetation composition, and tree age. These changes are apparently followed up by paralleled shifts in fungal community composition on forest soil with potential feedback on ecosystem functioning.
 The objective of the study was to screen fungal groups associated with the root system of P. sylvestris in stands affected by H.annosum s.s. to better understand the pathogenesis and development of root rot infection, as well as to recognize whether root size and disease severity affect diversity of fungi of the root system in the forest-steppe conditions of Ukraine. The additional object was to study other resident microflora of P. sylvestris root infested by H.annosum s.s. to find out whether the H. annosum s.s. impacts the overall diversity of other fungi.
 Materials and Methods
 The field study was carried out in 2018–2020. Field study sites were pure pine forest stands located in Kharkiv region (compartment 126, subcompartment 7, tract Bugri, Kharkiv Forest Research Station). Wood core and root samples from P. sylvestris were collected from the five infected (50–100 m apart from each other) and five non-infected trees (up to 500 m apart from the infested area and 50–100 m apart from each other). Wood and root samples were used for fungal culturing and direct sequencing using ITS1F and ITS4 primers.
 Results
 In the present study, we tried to evaluate fungal communities across diseased Pinus sylvestris stands and investigated correlations between taxonomic composition and forest health. Not surprisingly, root rot infestation had a significant effect on root-associated fungal abundance and diversity. During disease development, the root-associated fungal community shifted in composition from dominance by saprotrophic fungi to ectomycorrhizal and pathogenic fungal species. Our results suggested that maintenance of functional diversity in the root-associated fungal community may sustain long-term forest health or even root rot resistance to some extent by retaining a capacity for symbiosis-driven recycling of organic nutrients; however, this hypothesis is necessary to carefully examine and prove further.
 Conclusions
 Fungal culturing from 10 surface-sterilized wood cores resulted in 21 fungal cultures, 2.1 per wood segment. Direct sequencing from 40 surface-sterilized segments of lateral roots resulted in 247 fungal sequences or 6.2 per root segment on average. The most dominant fungi from the infested trees of Pinus sylvestris were Dactylonectria macrodidyma (4.98%), Acremonium sp (4.52%), Cladosporium cladosporioides (4.07%) from Ascomycota and Heterobasidion annosum s.s. (4.07%) from Basidiomycota, while for non-infested group Unidentified Ascomycota175244 (13.19%), Penicillium spinulosum (9.89%), Acremonium sp. (8.79%), Bionectriaceae sp. (8.79%) were the most common.
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Esfenvalerate biodegradation by marine fungi is affected by seawater and emulsifier formulation.

Pesticides already were detected in the oceans, and their fates require evaluation in these environmental conditions. Therefore, marine-derived fungi were assessed for Esfenvalerate biodegradation, approaching the effects of seawater and use of commercial emulsifiable formulation. Residual pesticide and four metabolites were quantified. Furthermore, kinetics were determined for the three tested strains (Microsphaeropsis sp. CBMAI 1675, Acremonium sp. CBMAI 1676, and Westerdykella sp. CBMAI 1679). These facultative marine fungi biodegraded up to 87 ± 2% of 100mg L-1 Esfenvalerate in liquid media. However, Esfenvalerate biodegradation was faster in low salinity conditions than in artificial seawater. Moreover, rates of consumption were higher for Esfenvalerate in the pure form than for the commercial emulsifiable formulation. These results suggest that half-life of Esfenvalerate formulated with inert ingredients in seawater can have a double prolongation effect that can contribute to health and environmental issues.

Marine fungi showing multifunctional activity against human pathogenic microbes and cancer.

Multifunctional drugs have shown great promise in biomedicine. Organisms with antimicrobial and anticancer activity in combination with antioxidant activity need further research. The Red Sea and the Arabian Gulf coasts were randomly sampled to find fungi with multifunctional activity. One hundred strains (98 fungi and 2 lichenized forms) were isolated from 15 locations. One-third of the isolates inhibited clinical bacterial (Staphylococcus aureus, Bacillus subtilis, Vibrio cholerae, Salmonella typhi, S. paratyphi) and fungal pathogens (Talaromycets marneffei, Malassezia globose, Cryptococcus neoformans, Candida albicans, Aspergillus fumigatus) and four cancer cell lines (Hep G2 liver, A-549 lung, A-431skin, MCF 7 breast cancer). Bacterial and cancer inhibition was often accompanied by a high antioxidant activity, as indicated by the principal component analysis (PCA). PCA also indicated that fungal and bacterial pathogens appeared to be inhibited mostly by different marine fungal isolates. Strains with multifunctional activity were found more from the Rea Sea than from the Arabian Gulf coasts. The highest potential for multifunctional drugs were observed for Acremonium sp., Acrocalymma sp., Acrocalymma africana, Acrocalymma medicaginis (activity reported for the first time), Aspergillus sp. Cladosporium oxysporum, Emericellopsis alkaline, Microdochium sp., and Phomopsis glabrae. Lung, skin, and breast cancers were inhibited 85%-97% by Acremonium sp, while most of the isolates showed low inhibition (ca 20%). The highest antifungal activity was observed for Acremonium sp., Diaporthe hubeiensis, Lasiodiplodia theobromae, and Nannizia gypsea. One Acremonium sp. is of particular interest to offer a multifunctional drug; it displayed both antifungal and antibacterial activity combined with high antioxidant activity (DPPH scavenging 97%). A. medicaginis displayed combined antibacterial, anticancer, and antioxidant activity being of high interest. Several genera and some species included strains with both high and low biological activities pointing out the need to study several isolates to find the most efficient strains for biomedical applications.

Effect of fertilization regimes on continuous cropping growth constraints in watermelon is associated with abundance of key ecological clusters in the rhizosphere

The deterioration of the microbiome within the rhizosphere is the main reason behind continuous cropping obstacles and is affected by fertilization regimes. However, the potential associations among fertilization regimes, rhizosphere microbial communities, and the severity of continuous cropping obstacles are poorly understood. Here, we investigated how three-year fertilization regimes (including no fertilizer, chemical fertilizer, organic fertilizer, combination of chemical and organic fertilizer, and bio-organic fertilizer application) affect the rhizosphere microbiome and its associations with continuous cropping growth constraints during the whole growing period of watermelon, using a rhizobox system under greenhouse conditions. The results showed that different fertilization treatments induced drastic shifts in the richness, structure, and composition of rhizosphere microbial communities, whereas the growth stages induced few changes. Compared with no fertilizer treatment, the continuous application of chemical fertilizer inhibited the growth of watermelon. This was strongly associated with the reduced abundance of key ecological clusters within the bacterial co-occurrence network, which contains beneficial bacterial taxa, such as Lysobacter sp. and Haliangium sp. In contrast, continuous application of organic and bio-organic fertilizers promoted the growth of watermelon and was associated with the decreased abundance of key ecological clusters within the fungal co-occurrence network, which contains pathogenic fungal taxa, such as Fusarium sp., Cladosporium sp., and Acremonium sp. Overall, continuous chemical fertilizer application can induce severe continuous cropping obstacles by inhibiting the growth of beneficial bacteria. Continuous application of organic and bio-organic fertilizers can help alleviate such obstacles by suppressing pathogenic fungi. These findings reveal the microbial mechanisms underlying the effects of different fertilization regimes on continuous cropping growth constraints of watermelon.

Biodegradation of polycyclic aromatic hydrocarbons by Acremonium sp. activity

Chihuahua State is the largest apple producer in Mexico. To prevent apples from freezing during the winter, petroleum-based fuels are used to heat the orchards. In this research work, a microorganism isolated from inside of a fuel plastic container was identified through morphological analysis as the fungus Acremonium sp. By cultivating the fungus in potato dextrose agar medium (PDA), we were able to study the biodegradation rates of three polycyclic aromatic hydrocarbons (PAHs). The isolated microorganism was incubated at 28 ºC in M9 mineral liquid medium using phenanthrene, anthracene, and pyrene as the only carbon source at a concentration of 50 µg/mL. Degradation of PAHs was monitored using an environmentally friendly reverse phase ultra-high-performance liquid chromatography (UHPLC) system, with a C18 column, 30% water acidified at 0.1% with trifluoroacetic acid, and 70% acetonitrile as the mobile phase, 40 ºC column temperature, and UV detection at 254 nm. After 30 days of biodegradation (optimal time), the final mean concentration for individual degradation experiments were 2.51 µg/mL phenanthrene, 3.02 µg/mL anthracene and 5.53 µg/mL pyrene. Those final concentrations indicate degradation percentile of 95%, 94%, and 89%, respectively. Biodegradation experiments combining all three PAHs showed similarly high degradation percentiles of 93%, 94%, and 85% for phenanthrene, anthracene, and pyrene, respectively. The dry weight average at day 30 in the individual and combined degradation experiments was 2.34 mg/mg PAHs degraded.

Genetic Evidence in Favor of a Polyketide Origin of Acremeremophilanes, the Fungal "Sesquiterpene" Metabolites.

ABSTRACTEremophilanes are a large group of “sesquiterpenes” produced by plants and fungi, with more than 180 compounds being known in fungi alone. Many of these compounds are phytotoxic, antimicrobial, anticancer and immunomodulators, and hence are of great economic values. Acremeremophilanes A to O have earlier been reported in a marine isolate of Acremonium sp. We report here the presence of Acremeremophilane I, G, K, N, and O, in a plant beneficial fungus Trichoderma virens, in a strain-specific manner. We also describe a novel, P strain-specific polyketide synthase (PKS) gene cluster in T. virens. This gene cluster, designated amm cluster, is absent in the genome of a Q strain of T. virens, and in other Trichoderma spp.; instead, a near identical cluster is present in the genome of the toxic mold Stachybotrys chartarum. Using gene knockout, we provide evidence that acremeremophilanes are biosynthesized via a polyketide route, and not via the mevalonate/terpene synthesis route as believed. We propose here that the 10-carbon skeleton is a product of polyketide synthase, to which a five-carbon isoprene unit is added by a prenyl transferase (PT), a gene for which is present next to the PKS gene in the genome. Based on this evidence, we propose that at least some of the eremophilanes classified in literature as sesquiterpenes (catalyzed by terpene cyclase) are actually meroterpenes (catalyzed by PKSs and PTs), and that the core moiety is not a sesquiterpene, but a hybrid polyketide/isoprene unit.IMPORTANCE The article contradicts the established fact that acremeremophilane metabolites produced by fungi are sesquiterpenes; instead, our findings suggest that at least some of these well-studied metabolites are of polyketide origin. Acremeremophilane metabolites are of medicinal significance, and the present findings have implications for the metabolic engineering of these metabolites and also their overproduction in microbial cell factories.

Clinical Outcomes of Rose Bengal Mediated Photodynamic Antimicrobial Therapy on Fungal Keratitis with Their Microbiological and Pathological Correlation

Purpose To report the clinical outcome of Photodynamic Antimicrobial Therapy (PDAT) with Rose Bengal (RB) used as an early adjuvant therapy in patients with fungal keratitis and their microbiological and pathological correlation. Methods Patients with microbiologically confirmed fungal keratitis underwent PDAT-RB along with topical natamycin 5% drops hourly and oral ketoconazole 200 mg twice a day. This was performed by applying rose bengal (0.1%) to the de-epithelialized cornea for 30 minutes, followed by irradiation with a 6 mW/cm2 custom-made green LED source for 15 minutes (5.4 J/cm2). The corresponding fungal isolates were tested in vitro using PDAT-RB and corneal buttons were evaluated for correlation. Results Following informed consent, seven patients (male-5, female-2, mean age 47.7 years) with fungal keratitis were recruited. There were 3 cases each of Fusarium and Aspergillus flavus and 1 case of Acremonium sp. The average vertical and horizontal diameters of the corneal infiltrate were 4.12 ± 0.55 and 3.99 ± 1.19 mm, respectively. The average depth of corneal involvement was 283 ± 75.27µ as measured by anterior segment OCT. The clinical resolution was achieved in the cases with Fusarium keratitis with an average time of 39 days. Three cases of A. flavus and a single patient with Acremonium keratitis worsened and needed therapeutic keratoplasty (TPK) for resolution. Post-TPK, the corneal tissues grew A. flavus in one out of three cases and Acremonium sp. in one case. In vitro PDAT-RB experiment was performed on the corresponding fungal isolates grown from the corneal scraping. PDAT-RB produced clear inhibition of Fusarium and Acremonium sp. with no effect on the growth of A. flavus. Histopathologically, 2 out of 4 (50%) corneal buttons showed fungal filaments. Conclusions While the in vitro and in vivo results of PDAT-RB matched for Fusarium sp. and Aspergillus flavus keratitis being favourable in the former and non-favourable in the latter, these results were discrepant in Acremonium sp.

Acremocholone, an Anti-Vibrio Steroid from the Marine Mesophotic Zone Ciocalypta Sponge-Associated Fungus Acremonium sp. NBUF150.

Mesophotic coral ecosystems (MCEs) represent an underexplored source of intriguing natural products. Efforts to discover bioactive metabolites from sponge-associated fungi in MCEs identified a new steroid, acremocholone (1) and its three known analogs (2-4), from Acremonium sp. NBUF150. The Acremonium sp. NBUF150 was isolated from a Ciocalypta sponge located 70 m deep within the South China Sea. The planar structures and absolute configuration of 1-4 were determined from NMR-derived spectroscopic data, HR-ESI-MS, and X-ray crystallography. Compound 1 exhibited antimicrobial inhibition against Vibrio scophthalmi, V. shilonii and V. brasiliensis at minimum inhibitory concentrations of 8 μg/mL; compound 2 inhibited V. shilonii and V. brasiliensis at 8 and 32 μg/mL, respectively, and compound 4 inhibited growth of V. brasiliensis at 16 μg/mL. Sponge associated fungi from MCEs represent a promising resource of anti-Vibrio drug leads for aquaculture use.

Detection of fungi and yeast in the air dust outdoors of the city of Morelia, Mich, Mexico

The air we breathe contains suspended dust particles which can host filamentous fungi that can cause respiratory problems and allergies in humans. Generally, the propagules can survive depending upon the environmental conditions, such as humidity, temperature and cleanness. The aim of this research work was to detect the fungi in dust of outdoor air at the city of Morelia, Mich, México. So far similar study is not reported in this city. For this purpose, the samples were collected at fixed places from October to December 2017 at two times during the day. Results demonstrate the existence of the various fungi genera, from high to low concentration levels: Aspergillus fumigatus, Penicillium sp, A. niger, Monilia sp, Alternaria sp, Mucor sp, Acremonium sp Cladosporium sp, and Chrysosporium sp including more than one genus of yeasts such as Candida tropicalis and Rhodotorula rubra were isolated from the dust precipitated from the outside air, regardless of the intensity of solar radiation The existence of A. fumigatus and C. tropicalis represents a risk for human population who lives in this city in that sense a sanitary measures should be apply.

Acremopeptaibols A-F, 16-Residue Peptaibols from the Sponge-Derived Acremonium sp. IMB18-086 Cultivated with Heat-Killed Pseudomonas aeruginosa.

Six new 16-residue peptaibols, acremopeptaibols A-F (1-6), along with five known compounds, were isolated from the cultures of the sponge-associated fungus Acremonium sp. IMB18-086 grown in the presence of the autoclaved bacterium Pseudomonas aeruginosa on solid rice medium. The peptaibol sequences were established based on comprehensive analysis of 1D and 2D NMR spectroscopic data in conjunction with HRESIMS/MS experiments. The configurations of the amino acid residues were determined by advanced Marfey's analysis. Compounds 1-6 feature the lack of the highly conserved Thr6 and Hyp10 residues in comparison with other members of the SF3 subfamily peptaibols. A plausible biosynthetic pathway of compounds 1-6 was proposed on the basis of genomic analysis. Compounds 1, 5, 7, and 10 exhibited significant antimicrobial activity against Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Candida albicans. Compounds 7-10 showed potent cytotoxicities against the A549 and/or HepG2 cancer cell lines.

PTP1B Inhibitory Secondary Metabolites from an Antarctic Fungal Strain Acremonium sp. SF-7394.

Chemical investigation of the Antarctic lichen-derived fungal strain Acremonium sp. SF-7394 yielded a new amphilectane-type diterpene, acrepseudoterin (1), and a new acorane-type sesquiterpene glycoside, isocordycepoloside A (2). In addition, three known fungal metabolites, (−)-ternatin (3), [D-Leu]-ternatin (4), and pseurotin A (5), were isolated from the EtOAc extract of the fungal strain. Their structures were mainly elucidated by analyzing their NMR and MS data. The absolute configuration of 1 was proposed by electronic circular dichroism calculations, and the absolute configuration of the sugar unit in 2 was determined by a chemical method. The inhibitory effects of the isolated compounds on protein tyrosine phosphatase 1B (PTP1B) were evaluated by enzymatic assays; results indicated that acrepseudoterin (1) and [D-Leu]-ternatin (4) dose-dependently inhibited the enzyme activity with IC50 values of 22.8 ± 1.1 μM and 14.8 ± 0.3 μM, respectively. Moreover, compound 1 was identified as a competitive inhibitor of PTP1B.