A new hydronaphthalenone from the mangrove-derived Daldinia eschscholtzii PSU-STD57

One new hydronaphthalenone derivative (1) was isolated from the broth extract of the endophytic fungus Daldinia eschscholtzii PSU-STD57 together with five known compounds, isosclerone (2), 8-methoxy-1-naphthol, 1,8-dimethoxynaphthalene, 2,6-dihydroxyphenyl-1-butan-1-one and tyrosol. The structures were assigned by spectroscopic methods. All the compounds were tested for antimicrobial activity against Staphylococcus aureus, methicillin-resistant S. aureus and Microsporum gypseum.     

Anti-inflammatory polyketides from the mangrove-derived fungus Ascomycota sp. SK2YWS-L

A pair of novel 2,3-diaryl indone derivatives (+)- and (?)-ascomindone D [(+)-1 and (?)-1, respectively], as well as two new prenylated polyketides ascomfurans C (2) and ascomarugosin A (3) were obtained from the culture of a mangrove endophytic fungus Ascomycota sp. SK2YWS-L together with three known compounds (4–6). The enantiomers (+)-1 and (?)-1 were purified through chiral HPLC separation, which represented the first example of resolving 2,3-diaryl indone atropisomers in natural products. The structures of the new compounds were determined on the basis of interpretation of spectroscopic data including X-ray diffractions and the absolute configurations of (+)-1 and (?)-1 were elucidated by ECD calculations. The biosynthesis pathway was proposed. In the anti-inflammatory assay, (+)-1 and (?)-1 exhibited potential anti-inflammatory effects by inhibiting against the production of nitric oxide (NO) in lipopolysaccharide (LPS)-induced RAW 246.7 mouse macrophages with the IC₅₀ values of 17.0 and 17.1 μM, respectively.     

Two new secondary metabolites from a mangrove-derived fungus Cladosporium sp. JJM22

Two new compounds (1 and 2), together with six known compounds (3–8), were obtained from the Cladosporium sp. JJM22, an endophytic fungus isolated from the stem bark of the mangrove plant Ceriops tagal collected in South China Sea. Their structures were elucidated on the basis of detailed spectroscopic analysis. The absolute configurations of 1 and 2 were confirmed by the comparison of optical rotation and the CD data with those of known compounds. The inhibitory activities of the isolated compounds against six terrestrial pathogenic bacteria and human cervical carcinoma Hela cell line were evaluated. Compound 3 exhibited a broad spectrum of antibacterial activities.     

A novel 10-membered macrocyclic lactone from the mangrove-derived endophytic fungus Annulohypoxylon sp.

A novel 10-membered macrolactone, hypoxylide (1), was isolated from the endophytic fungus Annulohypoxylon sp. that was obtained from the Mangrove plant Rhizophora racemosa. The structure and absolute configuration of 1 were unambiguously elucidated by comprehensive 1D and 2D NMR, as well as by HRESIMS and ECD spectroscopic analyses. Hypoxylide (1) features an unprecedented polyketide skeleton comprised of a trihydroxynaphthalene-dione moiety fused to a decalactone ring. A plausible biosynthetic pathway of this novel metabolite is proposed.     

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.     

Two new acids from mangrove endophytic fungus (No. ZZF13)

Two new acids 1 and 2, together with a known compound, purpactin A (3), were isolated from endophytic fungus No. ZZF13. Their structures were elucidated on the basis of 1D, 2D NMR, and HREIMS spectra. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp.336-337, July-August, 2008. Original articlesubmitted April 24, 2007.     

Two new metabolites of a marine endophytic fungus (No. 1893) from an estuarine mangrove on the South China Sea coast

The endophytic fungus No. 1893 was isolated from the dropper of Kandelia candel from an estuarine mangrove on the South China Sea coast. The ethyl acetate extract of the fermentation broth of this fungus strain exhibited cytotoxicity toward NCI4460 and Bel-7402, and high activities against Heliothis armigera (Hühner) and Sinergasilus spp. Two new lactones, 1893A (1) and B (2), together with 5-(p-hydroxybenzyl)hydantoin and two cyclodipeptides, cyclo-(Ser-Leu) and cyclo-(Phe-Gly), were isolated from the extract. Their structures were determined by spectroscopic experiments, including X-ray diffraction.     

Two new diterpenoids from the endophytic fungus Trichoderma sp. Xy24 isolated from mangrove plant Xylocarpus granatum

Two new harziane diterpenoids, named(9R,10R)-dihydro-harzianone(1) and harzianelactone(2), were isolated from the endophytic fungus Trichoderma sp. Xy24 by using various column chromatography techniques. Their structures were determined on the basis of extensive spectroscopic(HR-ESI-MS, 1D NMR, 2D NMR and CD) analyses. Among them, 1 was the reductive product of harzianone and 2 was the Baeyer–Villiger monooxygenase catalyzed oxidation product of harzianone. Compound 1 exhibited cytotoxic activity against He La and MCF-7 cell lines with IC_(50) values of 30.1 μmol/L and 30.7 μmol/L,respectively.     

A new phthalide from the endophytic fungus Xylaria sp. GDG-102

A new phthalide derivative, xylarphthalide A (1), along with two known compounds (-)-5-carboxylmellein (2) and (-)-5-methylmellein (3), were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from the Chinese medicinal plant Sophora tonkinensis. Their structures were identified by MS and NMR experiments, and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. Compound 1–3 showed antibacterial activities against Bacillus megaterium, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Shigella dysenteriae with MIC values of 12.5–25 μg/mL.     

A new bioactive diterpenoid from pestalotiopsis adusta,an endophytic fungus from clerodendrum canescens

Bioassay-guided fractionation of the culture extract of Pestalotiopsis adusta, an endophytic fungus isolated from the medicinal plant Clerodendrum canescens, led to the isolation of one new, (10S)-12,16-epoxy-17(15→16)-abeo-3,5,8,12,15-abietapentaen-2,7,11,14-tetraone (1), and four known diterpenoids, teuvincenone F (2), uncinatone (3), coleon U (4), coleon U-12-methyl ether (5). These structures were identified by using spectroscopic methods, including UV, MS, 1D and 2D NMR experiments. This is the first report of these compounds being isolated from a Pestalotiopsis species. The cytotoxic activities of the compounds were evaluated, and compounds 1 and 3 demonstrated cytotoxic activities against the HL-60 tumour cell line (IC₅₀ ＜ 20 μM).     

A new isocoumarin from mangrove endophytic fungus (No. dz17) on the South China Sea coast

A new isocoumarin, 3,4-dihydro-6-methoxy-8-hydroxy-3,4,5-trimethylisocoumarin-7-carboxylic acid methyl ester (1), together with three known compounds, 3,4-dihydro-4,8-dihydroxy-3,5-dimethylisocoumarin (2), 3,4-dihydro-8-hydroxy-3-methylisocoumarin-5-carboxylic acid (3), and Entinclole SB (4) were isolated from the mangrove endophytic fungus (No. dz17). The structure of the compound 1 was elucidated by analysis of spectroscopic data. Primary bioassays showed that 1 exhibited weak cytotoxicity against Hep-2 and HepG2 cells. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 543–545, November–December, 2007.     

Two new polyhydroxysterols produced by Fusarium solani,an endophytic fungus from Chloranthus multistachys

A highly antagonistic endophytic fungus, designated strain CL39, was originated from the leaves of Chloranthus multistachys collected in Wulong of Chongqing municipality of China in November 2015. The strain was identified as Fusarium solani based on morphological characteristics, 5.8S gene and internal transcribed spacer sequence analysis. Two new compounds, 2β, 9α-dihydroxy-5α-methoxyergosta-7, 22-diene (1), 2β, 6β-dihydroxy-5α-methoxyergosta-7, 22-diene (2) have been isolated from the culture broth of the strain. Structures of the new compounds were elucidated by detailed analysis of their spectroscopic data aided by the comparison with reported data of related derivatives, and found to belong to the polyhydroxylated steroids with a hydroxyl at C-2 instead of C-3, a rare structure among the steroids. The extract of this strain and all isolated compounds were evaluated for their antagonistic activities.     

Huperzine A production by Paecilomyces tenuis YS-13, an endophytic fungus isolated from Huperzia serrata

Huperzine A (HupA), a naturally occurring alkaloid in the plant family Huperziaceae, has drawn great interest for its potential application in Alzheimer disease therapy. Our primary objective was to identify alkaloid- and HupA-producing fungi from the Chinese folk herb, Huperzia serrata. We established a rapid and efficient model for screening HupA-producing endophytic fungal strains. The presence of HupA in Paecilomyces tenuis YS-13 was analysed by thin-layer chromatography, high-performance liquid chromatography and mass spectrometry. The fermentation yield of HupA was 21.0 μg/L, and the IC₅₀ of the crude extract of YS-13 fermentation broth was 1.27 ± 0.04 mg/mL. This is the first report of P. tenuis as a HupA-producing endophyte isolated from Huperziaceae.     

南海红树林内生真菌ZSU-H26生物碱类代谢产物的研究

海洋微生物资源由于具有可持续开发性,而且其活性物质不像来源于其它海洋生物(如海绵、海藻、海兔、珊瑚等)产生的生物活性物质,其生产不受天然资源难再生的限制,能通过发酵进行胞外生产,与现代微生物技术相结合,较容易实现工业化生产,特别是其生产不对环境造成危害,符合当今绿色化学发展的方向.     

Asperterzine,a symmetric aromatized derivative of epipolythiodioxopiperazine,from the endophytic fungus Aspergillus terreus PR-P-2

A new symmetric aromatized derivative of epidithiodioxopiperazine, asperterzine (1), was isolated from the endophytic fungus Aspergillus terreus PR-P-2. The structure was elucidated by various spectroscopic and the cytotoxicity against HL-60 cell line was also evaluated.     

Systematical NMR analysis of swainsonine,a mycotoxin from endophytic fungus Alternaria oxytropis

Swainsonine (SW, 1 ), a unique indolizine with poly‐hydroxyl groups, was re‐isolated from the plant endophytic fungus Alternaria oxytropis. The structure (including planar structure and relative configuration) was systematically elucidated by NMR spectra (including ¹H, ¹³C, ¹H‐¹H COSY, HMQC, HMBC, and NOESY spectra in DMSO‐d₆ and in CD₃OD); ¹H NMR spectra of the modified Mosher's products were first used to determine the absolute configuration of SW. More importantly, the complex coupled features of H‐7α, H‐7β, and H‐6α in the ¹H NMR spectrum of ( 1 ) were analyzed in details, which will provide aids for the planar and relative configuration determination of analogs.     

A new benzopyrans derivatives from a mangrove-derived fungus Penicillium citrinum from the South China Sea

One new benzopyran derivative (2R^*,4R^*)-3,4-dihydro-5-methoxy-2-methyl-2H-1-benzopyran-4-ol (1), together with five known compounds (2?6), were obtained from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Brguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All compounds were evaluated for their antibacterial activities. Compound 6 exhibited potent inhibitory activity against Bacillus subtilis, Bacillus cereus and Micrococcus tetragenus with the same MIC values of 6.94 μM.     

南海红树内生真菌1947号次级代谢产物的研究

红树植物是一类生长于潮间带的乔灌木的通称。近年来,国内外对红树内生真菌代谢产物的研究呈快速发展趋势。本课题组自上世纪90年代以来开始研究南海红树内生真菌代谢产物,迄今已从南海红树内生真菌分离得到许多有意义的代谢产物[1-5]。编号为1947号的内生真菌分离自香港江口红     

Polyketides with different post-modifications from desert endophytic fungus Paraphoma sp.

Three new polyketides 4,6,8-trihydroxy-5-methyl-3,4-dihydronaphthalen-1(2H)-one (1), 5,7-dihydroxy-3-(1-hydroxyethyl)-3,4-dimethylisobenzofuran-1(3H)-one (2) and 1-(4-hydroxy-6-methoxy-1,7-dimethyl-3-oxo-1,3-dihydroisobenzofuran-1-yl) ethyl acetate (3) together with seven known analogues (4–10) were isolated from desert endophytic fungus Paraphoma sp. The structures of these compounds were elucidated by analysis of NMR data. The absolute configuration of (1–3) was established on the basis of CD experiments. The possible biosynthetic pathway of compounds (1–10) was suggested, which implied that these secondary metabolites might be originated from polyketide biosynthesis with different post-modification reactions. Compounds 2, and 5–8 were evaluated for bioactivities against plant pathogen A. solani, whereas none of them displayed any biological effects. In addition, compounds 1, 2 and 5–10 were also tested for cytotoxic activities against three human cancer cell lines (HepG2 cells, MCF-7 cells and Hela cells) without biological effects.     

A new polyketide synthase nonribosomal peptide synthetase hybrid metabolite from plant endophytic fungus Periconia sp.

A new polyketide synthase–nonribosomal peptide synthetase(PKS–NRPS) hybrid metabolite, named pericoannosin B(1), was isolated from endophytic fungus Periconia sp. F-31 of the medicinal plant Annona muricata. The structure and absolute configuration were elucidated by means of extensive spectroscopic analyses(HRMS, NMR, IR, and CD).