Search

The secondary metabolites of endophytic fungus Alternaria sp. SK6YW3L were studied. The fungus was isolated from the fresh fruit of mangrove plant Sonneratia apetala collected from Guangxi Shankou Mangrove Nature Reserve. The strain was fermented and cultured with 3% salinity rice medium, and then subjected to silica gel column chromatography, semi-preparative HPLC, Sephadex LH-20, ODS and recrystallization. Thirteen anthraquinones including 7-acetyl-l, 3, 6-trihy-droxyanthracene-9, 10-dione (1), (11S) -1, 3, 6-trihydroxy-7-(1-hydroxyethyl) anthracene-9, 10-dione (2), 7-0-demethyl-6-deoxybostrycoidin (3), altersolanol A (4), dactylariol (5), altersolanol B (6), emodin (7), emodin-3-methyl ether (8), 6-hydroxy -aloeemodin (9), anthraquinone A (10), 1, 5-dihydroxy-7-methoxy-2- methylanthracene-9, 10-dione (11), alterporriol N (12) and alterporriol A (13), were identified using modern spectroscopy techniques such as 1D, 2D NMR and MS, and then comparing with literature data. The single crystal structure of compounds 1 and 4 were analyzed by single-crystal X-Ray diffraction experiment using CuK a radiation. Among them, compound 1 was obtained as a new single crystal and the absolute configuration of compound 4 was determined to be 5R, 6S, 7R, 8S. The absolute configurations of other compounds were determined by comparing optical rotation and CD data. In the bioactivity assay, compounds 1-3 exhibited a-glucosidase inhibitory activity with IC50 values of (210.1 ± 1.2), (125.8 ± 1.5) and (68.7 ± 1.3) ^mol/L, respectively. [ABSTRACT FROM AUTHOR]

Mangrove endophytic fungi represent significant and sustainable sources of novel metabolites with unique structures and excellent biological activities, attracting extensive chemical investigations. In this research, two novel heterodimeric tetrahydroxanthones, aflaxanthones A (1) and B (2), dimerized via an unprecedented 7,7′-linkage, a sp3-sp3 dimeric manner, were isolated from the mangrove endophytic fungus Aspergillus flavus QQYZ. Their structures were elucidated through high resolution electrospray ionization mass spectroscopy (HRESIMS) and nuclear magnetic resonance (NMR) spectroscopy, the absolute configurations of them were determined by a single-crystal X-ray diffraction combined with calculated electronic circular dichroism (ECD) spectra and a 1D potential energy scan. These compounds were evaluated for antifungal activities in vitro and exhibited broad-spectrum and potential antifungal activities against several pathogenic fungi with minimum inhibitory concentration (MIC) values in the range of 3.13–50 μM. They also performed moderate antibacterial activities against several bacteria with MIC values in the range of 12.5–25 μM. This research enriched the resources of lead compounds and templates for marine-derived antimicrobial drugs. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Co‐culturing the mangrove endophytic fungus Penicillium sclerotiorum THSH‐4 with Penicillium sclerotiorum ZJHJJ‐18 in PDB medium resulted in the production of nine new azaphilones derivatives, peniazaphilones A—I (1—9), and six known azaphilones derivatives (10—15). Their structures were elucidated by analysis of detailed spectroscopic data, single‐crystal X‐ray diffraction, ECD spectra, 13C NMR calculation and DP4+ analysis. It is noteworthy that compound 1 with an isoquinoline quinone moiety, was isolated from natural source for the first time. Besides, compound 2 is the third reported phenylhydrazone derivative from fungi. In the bioactivity assays, compounds 1, 12, 14 and 15 (IC50 = 4.71—17.64 μmol/L) exhibited potent inhibition of LPS‐induced NO release from RAW264.7 without obvious cytotoxicity within 50 μmol/L compared to the positive control indomethacin (IC50 = 35.27 μmol/L). Moreover, compounds 1 and 13 displayed moderate to strong cytotoxicity to A549 and MDA‐MB‐435, with IC50 values in the range of 6.84—14.63 μmol/L. Together compound 1 showed moderate broad‐spectrum antibacterial activity. [ABSTRACT FROM AUTHOR]

OSMAC strategy is a useful tool for discovering series of metabolites from microorganism. Five new sambutoxin derivatives (1 – 2 , 4 , 8 – 9), together with seven known compounds (3 , 5 – 7 , 10 – 12), were isolated from Talaromyces sp. CY-3 under OSMAC strategy and guidance of molecular networking. Their planar structures and absolute configurations were determined by NMR, HRESIMS, ECD spectra and common biosynthetic pathway. In bioassay, compounds 1 – 12 showed cytotoxicity to tumor cell lines with IC 50 values in the range of 1.76–49.13 μM. The antitumor molecular mechanism of 10 was also explored. In vitro compound 10 significantly inhibited the growth and proliferation of two lung cancer cell lines (A549 and H1703). Furthermore, colony formation, EdU analysis, flow cytometry and Western blot analysis showed that 10 could induce cell cycle arrest in G0/G1 phase by promoting the expression of p53 and p21. The molecular mechanism of its antitumor effects in vitro is that 10 arrests the cell cycle by activating the p21/CyclinD1/Rb signaling pathway and the p53 pathway. Our results identified a lead small molecule compound with efficient antitumor growth and proliferation activity. [Display omitted] • Five new 2-hydroxy-4-pyridone derivatives were isolated from Talaromyces sp. CY-3. • Compound 1 represents of the first sambutoxin with 7 R and 11 S configurations. • SARs of sambutoxins on cytotoxicity to tumor cell lines were discussed. • 10 arrests the cell cycle by activating the p21/CycinD1/Rb signaling pathway. [ABSTRACT FROM AUTHOR]

Three rare natural sulfonamide products, sargassulfamide A (1), together with two unreported sulfonamides pestasulfamides B (2) and A (3) were obtained from mangrove endophytic fungus Pestalotiopsis sp. HNY36-1D under the guidance of chemical and biological autoradiography. Their structures were determined by 1D and 2D NMR, HR-ESI-MS, as well as single crystal X-ray diffraction. It was noteworthy that sulfonamide derivatives were obtained from metabolites of fungi for the first time. In bioassay, compounds 1 and 3 showed moderate acetylcholinesterase (AChE) inhibitory activities with IC 50 values 28.41 and 11.94 μM, respectively. The structure-activity relationships (SARs) analysis suggested that the existence of hydrogen atom on the N atom of sulfonamide derivatives and the closed loop of cyclic dipeptide were beneficial to the activity. The molecular docking studies indicated that 1 and 3 were near the center of the active pocket of AChE, while 2 was at the edge of the protein due to the large steric hindrance. [Display omitted] [ABSTRACT FROM AUTHOR]

Four new steroids (1–4) were isolated from the mangrove endophytic fungus Phoma sp. SYSU-SK-7. Compounds 1–2, with an unusual aromatic B ring skeleton, exhibited potent anti-inflammatory and α -glucosidase inhibitory activities. Molecular docking studies were performed to investigate the interaction of compounds 1 and 2 with iNOS protein. • Four new steroids were isolated from the mangrove endophytic fungus Phoma sp. SYSU-SK-7. • Phomosterols A (1) and B (2) were characterized by an unusual aromatic B ring skeleton moiety. • Phomosterols A (1) and B (2) exhibited potent anti-inflammatory and α -glucosidase inhibitory activities. Four new steroids phomosterols A-B (1 – 2), phomopenes A-B (3 – 4) and one known analogue (5) were isolated from the mangrove endophytic fungus Phoma sp. SYSU-SK-7. Their structures and absolute configurations were determined via NMR data, single-crystal X-ray diffraction analysis, and ECD calculations. Compounds 1–2 contain an unusual aromatic B ring skeleton in sterols, and compound 1 represent the first crystal structure described. Compounds 1 , 2 and 5 showed inhibitory activities against nitric oxide (NO) production in lipopolysaccharides (LPS) induced RAW 264.7 cells with IC 50 values of 13.5, 25.0 and 12.5 μM, respectively. Then, the affinities between new bioactive compounds (1 and 2) with nitric oxide synthase (iNOS) were researched by molecular docking studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nine new azaphilone derivatives were isolated from the mangrove endophytic fungus Penicillium sclerotiorum ZJHJJ-18. • The absolute configurations of 1 – 9 were determined by ECD calculation and chemical transformations. • Compounds 3 – 5 exhibited significant inhibitory activities against NO production with IC 50 values ranging from 6.30 to 9.45 μM. • Molecular docking study implied the probable binding interaction of bioactivity compounds 3 – 5 with inducible nitric oxide synthase (iNOS). Nine undescribed azaphilone derivatives, sclerazaphilones A–H (1 – 9), and three known analogues (10 – 12), were obtained and identified from the fermented rice cultures of a mangrove endophytic fungus Penicillium sclerotiorum ZJHJJ-18. 1D and 2D NMR, HRESIMS and spectral data indicated the chemical structures of 1 – 9 , and their absolute configurations were assigned by experimental and computational analyses of electronic circular dichroism (ECD) spectra, and application of the chemical transformations. Compounds 1 – 4 were the first reported N -containing azaphilone derivatives with 5/6 dicyclic core. The bioassay results showed that compounds 3 – 5 exhibited effective inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells with IC 50 values in the range of 6.30–9.45 μM. Moreover, a molecular docking study was conducted to investigate the probable binding interaction of 3 – 5 with inducible nitric oxide synthase (iNOS). [ABSTRACT FROM AUTHOR]

• Eight new sesquiterpenoids (2 , 4 – 6 and 10 – 13) were isolated from the fungus Phomopsis sp. SYSU-QYP-23. • The absolute configuration of the side chain in compound 1 was first defined by modified Mosher's method. • Compounds 1 – 7 exhibited potent inhibitory activities against NO production with IC 50 values ranging from 8.6 to 14.5 μM. • Molecular docking studies implied the probable binding interaction of bioactivity of compounds 1 – 9 with nitric oxide synthase (iNOS). Eight new sesquiterpene derivatives (2 , 4 – 6 and 10 – 13), along with five known analogues were isolated from the mangrove endophytic fungus Phomopsis sp. SYSU-QYP-23. Their structures of new compounds were established by spectroscopic methods, and the absolute configurations were confirmed by single-crystal X-ray diffraction analysis and comparison of the experimental ECD spectra. The absolute configuration of the side chain in 1 was first defined by modified Mosher's method. Compounds 1 – 7 showed potent inhibitory activities against nitric oxide (NO) production in lipopolysaccharides (LPS) induced RAW 264.7 cells with IC 50 values ranging from 8.6 to 14.5 μM. The molecular docking results implied that the bioactive sesquiterpenes may directly bind with targeting residues in the active cavity of iNOS protein. [ABSTRACT FROM AUTHOR]

• Six new compounds (±)- 1, (±)- 2, 3 and 8 were isolated from the mangrove endophytic fungus Phomopsis sp. SYSUQYP-23. • The absolute configurations of (±)- 1 , (±)- 2 and 8 were determined by ECD calculation. • Compounds 3 – 9 exhibited significant inhibitory activities against NO production with IC 50 values ranging from 4.5 to 25.0 μM. • Molecular docking study implied the probable binding interaction of bioactivity compounds 4 and 5 with nitric oxide synthase (iNOS). Five new maleimide derivatives, (+)- and (−)- farinomalein F (1), (+)- and (−)- farinomalein G (2), farinomalein H (3) and one new linearly fused prenylated indole alkaloid phomoamide (8), along with five known compounds 4 – 7 and 9 were isolated from the mangrove endophytic fungus Phomopsis sp. SYSUQYP-23. Their structures and absolute configurations were determined by HRESIMS, spectroscopic and electronic circular dichroism (ECD) calculations. Bioassay results showed that compounds 3 – 9 exhibited significant inhibitory activities against nitric oxide (NO) production in lipopolysaccharides (LPS) induced RAW 264.7 cells, with IC 50 values ranging from 4.5 to 25 μM. Moreover, the molecular docking study implied the probable binding interaction of compounds 4 and 5 with nitric oxide synthase. [ABSTRACT FROM AUTHOR]