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In our continuous work on the isolation of endophytes, the endophytic fungal strain YIMF00209 was obtained from the roots of Gmelina arborea , which is an ethnic medicinal plant mainly distributed in Southeast Asia. The fermentation extracts of the strain exhibited significant antimicrobial activities against Staphylococcus aureus , Fusarium solani , and Escherichia coli. Based on morphological characteristics and phylogenetic analysis, it was identified as Talaromyces muroii. Four new polyketides, talaromurolides A-D (1 – 4), along with 26 known compounds (5 – 30), were isolated from the culture broth of the strain in two different media. Their structures were identified based on HRESIMS, NMR, and CD spectral data. Among them, compounds 2 , 4 – 6 , 19 , 22 , 24 , 27 , 28 , and 30 were isolated from the fermentation broth in CYM medium; compounds 1 , 3 , 7 – 18 , 20 , 21 , 23 , 25 , 26 , and 29 were obtained from the fermentation broth in PDB medium; and compounds 2 , 5 , and 30 were existed in both two media. Compounds 6 – 9 , 12 , 16 , 20 , 21 , 23 , 25 , and 29 were obtained from the genus Talaromyces for the first time. The antimicrobial activities of several compounds were assayed against six pathogens. Compound 1 exhibited inhibitory activities against S. aureus , E. coli , Candida albicans , Salmonella typhimurium , and Botrytis cinerea with MIC value of 64 μg/mL. Compound 25 exhibited antibacterial activity against E. coli with MIC value of 32 μg/mL. [Display omitted] [ABSTRACT FROM AUTHOR]

Aspercitrininone A (1), a novel polyketide featuring an unprecedented tetracyclic 6/6/6/5 spiral skeleton, was obtained from the rice fermentation cultures of the fungus Aspergillus cristatus together with five known compounds (2 – 6). Their structures were determined by HRESIMS data, 1D and 2D NMR spectroscopic analysis, and electronic circular dichroism (ECD) calculations. Aspercitrininone A was revealed as a new type of C/D cycle spiral structure and an unusual addition product of o-quinoid form citrinin with 2-methylterrefuranone. Compounds 1 , 4 , and 5 exhibited potent antibacterial activities with minimal inhibitory concentration (MIC) values from 13.2 to 67.3 μg/mL against four strains of human pathogenic bacteria in vitro. [Display omitted] • A novel polyketide aspercitrininone A was isolated from rice cultures of Aspergillus cristatus. • Aspercitrininone A possessed an unprecedented tetracyclic 6/6/6/5 spiral skeleton. • It could be formed by o-quinoid form citrinin with 2-methylterrefuranone through Michael addition reaction. • Aspercitrininone A exhibited antibacterial activities. [ABSTRACT FROM AUTHOR]

Two novel fungal polyketides, phometides A (1) and B (2), together with four known compounds (3–6), were isolated from the endophytic fungus Phoma sp. YUD17001 obtained from Gastrodia elata Blume. The structures were elucidated based on spectroscopic analyses, X-ray crystal diffraction, and time-dependent density functional theory/electronic circular dichroism (TDDFT/ECD) calculations. Structurally, phometide A (1) represented the first example of C 12 polyketide characterized by an unusual tetrahydrobenzofuran-3(2 H)-one core with an α , β -unsaturated ketone functionality, while phometide B (2) was an unprecedented molecule containing a 2-pentylcycloheptan-1-one scaffold. In an antimicrobial activity assay, phometide A (1) exhibited significant inhibitory activity against Staphylococcus aureus with MIC value of 4 μg/mL. Phometide B (2) showed moderate antifungal activity against Candida albicans with an MIC value of 16 μg/mL. Furthermore, compounds 1 and 2 were evaluated for their acetylcholinesterase inhibitory and cytotoxic activities. [Display omitted] • Two novel fungal polyketides were identified from the endophytic fungus Phoma sp. YUD17001. • Phometide A possess an unusual tetrahydrobenzofuran-3(2 H)-one functionality. • Phometide B is a novel polyketone containing a 2-pentylcycloheptan-1-one scaffold. • Phometides A and B demonstrated antimicrobial activity against S. aureus and C. albicans , respectively. [ABSTRACT FROM AUTHOR]

Three new polyketides named penialidins A–C ( 1 – 3 ), along with one known compound, citromycetin ( 4 ), were isolated from an endophytic fungus, Penicillium sp., harbored in the leaves of the Cameroonian medicinal plant Garcinia nobilis . Their structures were elucidated by means of spectroscopic and spectrometric methods (NMR and HRMS n ). The antibacterial efficacies of the new compounds ( 1 – 3 ) were tested against the clinically-important risk group 2 (RG2) bacterial strains of Staphylococcus aureus and Escherichia coli . The ecologically imposing strains of E. coli (RG1), Bacillus subtilis and Acinetobacter sp. BD4 were also included in the assay. Compound 3 exhibited pronounced activity against the clinically-relevant S. aureus as well as against B. subtilis comparable to that of the reference standard (streptomycin). Compound 2 was also highly-active against S. aureus . By comparing the structures of the three new compounds ( 1 – 3 ), it was revealed that altering the substitutions at C-10 and C-2 can significantly increase the antibacterial activity of 1 . [ABSTRACT FROM AUTHOR]

Abstract: Three new polyketides, manzamenones L–N (1–3), have been isolated from an Okinawan marine sponge of the genus Plakortis. The structures of 1–3 were elucidated on the basis of spectroscopic data. Manzamenones L–N (1–3) were new dimeric fatty-acid derivatives consisting of a tetrahydroindenone with three carboxy groups and two hexadecanyl chains. Manzamenones M (2) and N (3) showed antimicrobial activity against several bacteria and fungi. [Copyright &y& Elsevier]