Bamboo plays a crucial role in mitigating climate change. Among various microorganisms inhabiting bamboo, Apiospora is a common bambusicolous fungus that induces black spots, functioning either as a saprobe or as a plant pathogen. However, the diversity and ecological roles of Apiospora as an endophyte in bamboo remain poorly understood. This study explored the diversity and ecological functions of bambusicolous Apiospora in Phyllostachys bambusoides forests. Bamboo samples representing different stages—young (1-year-old, without black spots), mature (aged 3 years, few black spots), and dead (with many black spots)—were collected. Mycobiome analyses across different tissues (culm, leaf, root) and environmental samples (forest soil) revealed diverse Apiospora species throughout the bamboo lifecycle. Notably, Apiospora hysterina emerged as a prevalent endophyte, inhabiting not only mature but also younger, healthier bamboo stages. Biological activity assays, including antioxidant, antifungal, and plant hormone tests, indicated that A. hysterina exhibits potential mutualistic interactions beneficial to bamboo. Conversely, genomic analyses of carbohydrate-active enzyme profiles, effector/virulence factors, and putative biosynthetic gene clusters suggested potential pathogenic capabilities that may involve secondary metabolites, though functional validation is required. These findings reveal the widespread presence of Apiospora species as endophytes from the early to senescent bamboo stages, highlighting A. hysterina’s dual capacity as a symbiont and pathogen. Our study underscores the complexity of bambusicolous Apiospora’s ecological roles, emphasizing the need for further investigation into its interactions with bamboo ecosystems.
A new secondary metabolite, aspernigrin F (1), possessing a unique 2-benzylpyridine-4-one substructure along with six known fungal metabolites were isolated from marine-derived fungus Aspergillus sp. SF6390. The chemical structures of all metabolites were mainly determined by analysing 1D, 2D NMR and HRESI-MS data. The isolated metabolites were assayed for their anti-inflammatory and cytoprotective effects in various cell lines such as RAW264.7 macrophages, BV2 microglia cells, hippocampal HT22, and HepG2 cell lines.
Nine previously undescribed (1-9) and seven known (10-16) cycloartane-type triterpenoids were isolated and characterized from Combretum quadrangulare Kurz using physicochemical and spectroscopic methods. The absolute configurations of these compounds were determined through modified Mosher's method and quantum chemical calculation of electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) spectra. Their inhibitory activities against PCSK9 secretion were assessed, and a plausible structure-activity relationship was delineated. Compounds 2, 14, and 15 exhibited notable inhibitory effects on PCSK9 mRNA and protein levels, and significant PCSK9 mRNA inhibition was observed when co-treated with atorvastatin. Compound 15 showed the most potent activity, markedly enhancing LDL uptake compared to the negative control. In vivo pharmacokinetic studies confirmed that compound 15 exhibited higher distribution in the liver than plasma, where PCSK9 is predominantly synthesized. These findings emphasize the potential significance of the cycloartane-type triterpenoid scaffold in discovering PCSK9 inhibitors.
A new cytosporin derivative (1) and a new phenolic compound (2), together with cytosporin D (3), were isolated from an EtOAc extract of Apiospora xenocordella culture medium. The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The chemical structures of the new compounds were determined by using MS and NMR spectroscopic techniques, and the absolute configurations were established by the modified Mosher's method and quantum chemical calculation of electronic circular dichroism. UV radiation activates pro-inflammatory cytokines, such as TNF-alpha, a major contributor to skin aging through ROS generation and MMP-1 secretion. Cytosporin D (3) exhibited the inhibition of TNF-alpha-induced ROS and MMP-1. UV radiation activates pro-inflammatory cytokines including TNF-alpha which is a major contributor to skin aging through reactive oxygen species (ROS) generation and matrix metalloproteinase-1 (MMP-1) secretion. Cytosporin D (3) exhibited moderate inhibition against TNF-alpha-induced ROS and MMP-1. This compound docked computationally into the active site of MMP-1 (-5.9 kcal/mol). Compound 1, though not tested due to limited quantity, showed a docking simulation result (-6.0 kcal/mol) similar to cytosporin D (3), indicating potential activity.
Three new pimarane diterpenoids, libertellenones U-W (1-3), together with libertellenone C (4) and myrocin A (5) were isolated from an EtOAc-extract of Apiospora arundinis culture medium. The chemical structures of the new compounds were elucidated using MS, NMR, and CD spectroscopic data. Benign prostatic hyperplasia (BPH), the abnormal and pathological proliferation of epithelial and stromal cells in prostatic tissues, is a common disease in middle-aged and elderly men. In this study, the anti-BPH effects of myrocin A (5) were evaluated using BPH-1 and WPMY-1 cells. Treatment with myrocin A (5) exerted antiproliferative effects in BPH-1 and dihydrotestosterone (DHT)-stimulated WPMY-1 cells. In BPH, treatment with myrocin A (5) significantly suppressed the mRNA levels of androgen receptor (AR) and its downstream targets nuclear receptor coactivator 1 (NCOA1), proliferating cell nuclear antigen (PCNA) and kallikrein-related peptidase 3 (KLK3). Additionally, DHT-stimulated WPMY-1 cells demonstrated an upregulated mRNA levels of AR, NCOA1, PCNA, and KLK3. However, treatment with myrocin A (5) resulted in suppression of the mRNA levels. Moreover, myrocin A (5) docked computationally into the binding site of the androgen receptor (-5.5 kcal/mol).
Using mass spectrometry (MS)-guided isolation methods, a new thiodiketopiperazine derivative ( 1 ) and exserohilone ( 2 ) were isolated from an EtOAc-extract of Setosphaeria rostrata culture medium. The chemical structure of the new compound was elucidated by MS and NMR spectroscopy, and the absolute configurations were established by the quantum mechanical calculations of electronic circular dichroism. All isolated compounds were examined for their effects on reactive oxygen species (ROS) production, matrix metalloproteinase 1 (MMP-1) secretion, and procollagen type I α1 secretion in tumor necrosis factor (TNF)-α-induced human dermal fibroblasts. Compound 1 and exserohilone ( 2 ) exhibited the inhibition of TNF-α-induced ROS generation and MMP-1 secretion. Additionally, compound 1 and exserohilone ( 2 ) increased the procollagen type I α1 secretion. Compound 1 docked computationally into the active site of MMP-1 (−6.0 kcal/mol).
Three new fusidane-type nortriterpenoids, simplifusinolide A, 24-epi simplifusinolide A, and simplifusidic acid L (1-3), were isolated from the EtOAc extract of the Arctic marine-derived fungus Simplicillium lamellicola culture medium, together with fusidic acid (4) and 16-O-deacetylfusicid acid (5). The structures of the isolated compounds were elucidated by NMR and MS analyses. The absolute configurations of compounds 1-3 were established by the quantum mechanical calculations of electronic circular dichroism and gauge-including atomic orbital NMR chemical shifts, followed by DP4 + analysis. Benign prostatic hyperplasia (BPH) is a major urological disorder in men worldwide. The anti-BPH potentials of the isolated compounds were evaluated using BPH-1 and WPMY-1 cells. Treatment with simplifusidic acid L (3) and fusidic acid (4) significantly downregulated the mRNA levels of the androgen receptor (AR) and its downstream effectors, inhibiting the proliferation of BPH-1 cells. Specifically, treatment with 24-epi simplifusinolide A (2) significantly suppressed the cell proliferation of both BPH-1 and DHT-stimulated WPMY-1 cells by inhibiting AR signaling. These results suggest the potential of 24-epi simplifusinolide A (2), simplifusidic acid L (3) and fusidic acid (4) as alternative agents for BPH treatment by targeting AR signaling.
Polyhydroxyalkanoates (PHA) have emerged as a promising bio-compound in the industrial application due to their potential to replace conventional petroleum-based plastics with sustainable bioplastics. This study focuses on Halomonas sp. YJPS3-3, a halophilic bacterium, and presents a novel approach to enhance PHA production by exploiting its salt tolerance toward PHA biosynthesis. Through gamma irradiation-induced mutants with enhanced salt tolerance from 15% NaCl to 20% NaCl, mutant halo6 showing a significant 11% increase in PHA yield, was achieved. Moreover, the mutants displayed not only higher PHA content but also remarkable cell morphology with elongation. In addition, this research unravels the genetic determinants behind the elevated PHA content and identifies a corresponding shift in fatty acid composition favoring PHA accumulation. This novel mutant obtained from gamma irradiation with enhanced salt tolerance in halophilic bacteria opens up new avenues not only for the bioplastic industry but also for applications in the production of high-value metabolites.
In an effort to activate silent biosynthetic gene clusters, Streptomyces samsunensis DSM42010, a producer of geldanamycin, was cultured at four different pHs (4.5, 5.4, 6.6, and 7.4). An acidic culture condition (pH 5.4) was selected for a chemical investigation since S. samsunensis showed a different metabolic profile compared to when it was cultured under other conditions. Seven new (1-7) and four known (8-11) compounds were isolated from these cultures. The structures of the isolated compounds were determined by spectroscopic techniques and chemical derivatization. Relative and absolute configurations of the new compounds (1-5) were established using JBCA, PGME method, advanced Marfey's method, modified Mosher's method, and comparison of observed and calculated ECD data. Interestingly, compounds 1-3 were truncated versions of geldanamycin, and compound 4 was also deduced to originate from geldanamycin. Compound 5 was composed of 3-methyltyrosine and 6-hydroxy-2,4-hexadienoic acid connected through an amide bond. Compounds 6 and 7 were dihydrogenated forms of geldanamycin with a hydroxy substitution. It is possible that culturing this strain under acidic conditions interfered to some degree with the geldanamycin polyketide synthase, leading to production of truncated versions as well as analogues of geldanamycin. Compounds 1, 8, and 9 showed significant antivirulence activity, inhibiting production of alpha-toxin by methicillin-resistant Staphylococcus aureus without growth attenuation and global regulatory inhibition; compounds 1, 8, and 9 may become promising alpha-toxin-specific antivirulence leads with less risk of resistance development.
A bioactive molecular networking strategy has been applied to discovery of bioactive constituents from the fruits of Celastrus orbiculatus Thunb., which showed significant inhibitory effects on the α-MSH-induced melanin production in B16F0 melanoma cells. In the obtained molecular network, the nodes with relatively high bioactive scores were prioritized for isolation; as a result, 12 undescribed dihydro-β-agarofuran sesquiterpenes together with 15 known compounds were isolated from MeOH extracts of the fruits of C. orbiculatus. Their structures were elucidated based on the interpretation of NMR, HRESIMS, ECD data, and single crystal X-ray diffraction. Among the obtained isolates, celastorbin A and (1R,2S,4R,5S,7S,8S,9R,10S)-1,2,8-triacetoxy-9-cinnamoyloxydihydro-β-agarofuran, which possessed high bioactive scores in the molecular network, exhibited potent inhibitory effects on the α-MSH-induced melanin production in B16F0 cells with IC50 values of 4.1 and 2.0 μM, respectively.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Recently, microorganisms and their metabolites in the Antarctic marine environment have attracted attention as useful sources for novel therapeutics, including anticancer drugs. Here, we investigated the effects of citromycin, isolated from the Antarctic marine-derived fungus, Sporothrix sp., on human ovarian cancer cells. Citromycin inhibited the migration and invasion of human ovarian cancer SKOV3 and A2780 cells, but had no cytotoxic activity against them. Additionally, it inhibited the expression of epithelial–mesenchymal transition (EMT) markers and the activation of matrix metalloproteinase (MMP)-2 and MMP9. Moreover, extracellular signal-regulated kinase (ERK)-1/2 signaling was inhibited after citromycin treatment, and the ectopic expression of ERK negated the anti-invasive activity of citromycin. Our findings suggest that citromycin inhibits the migration and invasion of human ovarian cancer cells by downregulating the expression levels of EMT markers and MMP-2/9 via inhibition of the ERK1/2 pathway.
Estrogen is a vital hormone responsible for the development of the female reproductive system. Hence, estrogen deficiency in menopause increases various symptoms. This study aimed to discover biologically active compounds from an EtOAc-extract of Neopestalotiopsis clavispora culture medium which has previously shown estrogenic activity. A new α-pyrone ( 1 ) and a new tetramic acid derivative ( 2 ), together with hymenosetin ( 3 ) and pestalotiollide B ( 4 ), were isolated from the extract. The chemical structures of the new compounds were elucidated using MS and NMR spectroscopy, and the absolute configurations were established by quantum mechanical calculations of electronic circular dichroism and gauge-including atomic orbital NMR chemical shift, followed by DP4+ analysis. The isolated compounds were initially tested for their estrogenic activities using MCF-7 estrogen responsive human breast cancer cells. Hymenosetin ( 3 ) showed estrogenic activity by increasing the proliferation of MCF-7 cells at the concentration of 2.5 μM via the phosphorylation of estrogen receptor- α .
Two new tetrahydroprotoberberine N-oxides, 7R,14S-cis-tetrahydrocoptisine N-oxide (1) and 7R,14R-trans-tetrahydmeoptisine N-oxide (2) along with fourteen known compounds (3-16) were isolated from the aerial parts of Chelidonium mails. Their structures were elucidated by spectroscopic and spectrometric methods, such as 1D and 2D-NMR (HSQC, HMBC, NOESY) and HRESIMS. The absolute configurations of 1 and 2 were established by comparison of their experimental and calculated ECD data. All isolates were evaluated for their inhibitory effects on the nitric oxide production in LPS-induced RAW 264.7 macrophages, and compounds 2, 6-10, 13, and 15 showed significant inhibitory effects with the IC50 values ranging from 1.1-31.9 mu M.
Eight new naphtho [1,2-c]furan derivatives (1-8) along with six known analogues (9-14) were isolated from culture medium of the basidiomycete Basidioradulum radula. The structures of these compounds were identified using spectroscopic analysis, and their absolute configurations were resolved using X ray diffraction, ECD, and VCD. Compounds 7 and 14 inhibited the cell viability of human prostate cancer DU 145 cells with IC50 values of 7.54 +/- 0.03 mu M and 5.04 +/- 0.03 mu M, respectively. At 8 mu M, compounds 7 and 14 increased the percentage of apoptotic cells and upregulated the protein expression related to the apoptosis caspase pathways in DU 145 cells. Furthermore, the hallmarks of cells undergoing apoptosis, such as chromatin condensation, were also observed at this concentration. However, compound 7 and 14 showed no effect on the proliferation of splenocytes isolated from cyclophosphamide-induce immunosuppressed mice.
A new α -pyrone analog, arthrifuranone A ( 1 ) was isolated from an EtOAc-extract of Arthrinium pseudosinense culture medium. The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The chemical structure of the new compound was elucidated using MS and NMR spectroscopic techniques, and the absolute configuration was established by the Mosher’s method and gauge-including atomic orbital NMR chemical shift calculations, followed by DP4 + analysis. The isolated compound was evaluated for its estrogenic activity using the MCF-7 estrogen responsive human breast cancer cells. Compound 1 showed estrogenic activity by increasing the proliferation of MCF-7 cells at the concentration of 3.125 μM via phosphorylation of estrogen receptor- α .
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.
Inflammation is a vital process that maintains tissue homeostasis. However, it is widely known that uncontrolled inflammation can contribute to the development of various diseases. This study aimed to discover antiinflammatory metabolites from Penicillium bialowiezense. Seven spiroditerpenoids, including two new compounds, breviones P and Q (1 and 2), were isolated and characterized by various spectroscopic and spectrometric methods. All isolated compounds were initially tested for their inhibitory effects against lipopolysaccharideinduced nitric oxide (NO) production in RAW 264.7 macrophages. Of these, brevione A (3) exhibited this activity with a half-maximal inhibitory concentration value of 9.5 mu M. Further mechanistic studies demonstrated that 3 could suppress the expression of pro-inflammatory cytokines and mediators, such as NO, prostaglandin E2, interleukin (IL)-1 beta, tumor necrosis factor-alpha, IL-6, and IL-12 by inhibiting the activation of nuclear factor-kappa B and c-Jun N-terminal kinase.
Cudraisoflavone J (1), isolated from Cudrania tricuspidata, is a potent neuroprotective compound with a chiral center. Herein, we report the first total synthesis of racemic cudraisoflavone J (1) using a Claisen rearrangement and a Suzuki coupling reaction as the key steps. Racemic secondary alcohol was kinetically resolved to give (+)- and (-)-cudraisoflavone J with up to 97 and 88% enantiomeric excess, respectively. The modified Mosher's method was used to elucidate the absolute configuration of naturally occurring cudraisoflavone J.
Bioactivity-guided isolation of a MeOH extract of Aralia cordata led to the isolation of four new ent-pimarane diterpenoids (1-4) and a diacetylene (5) together with 21 known compounds (6-26). Their structures were established based on the interpretation of one- and two-dimensional NMR and HRESIMS data. The absolute configurations of the new isolates were determined by electronic circular dichroism data analysis, single crystal X-ray diffraction, and Mosher's esterification method. All compounds exhibited inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages with IC50 values ranging from 1.1 to 69.4 μM.