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Abstract: One new angucyclinone derivative, amycomycin A (1), and one new angucycline, amycomycin B (2), along with 5 known compounds (3–7), were isolated from an actinobacterium Amycolatopsis sp. HCa1 associated with the grasshopper, Oxya chinensis. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR spectra. Compounds 1–7 were tested in vitro for their cytotoxic effects on five cell lines including human gastric adenocarcinoma cell line (BGC823), human hepatocarcinoma cell line (HepG2), human melanoma cell line (A375), human oral squamous carcinoma cell line (KB), and ghost cell line (Ghost-R5X4). Cell viability assays showed that compound 7 was active in four cell lines with IC50 values less than 18.0μM except in KB showing no activity up to 100μM. [Copyright &y& Elsevier]

Graphical abstract Highlights • New borrelidin-type macrolactones were isolated from an endophyte. • The structures of new compounds were elucidated by spectroscopic data. • Borrelidin A showed potent activity against M. luteus with MIC value of 1.0 μM. Abstract Three new borrelidin-type macrolactones, designated as borrelidins J−L (4 – 6), together with borrelidin A (1), borrelidin E (2), and 12-desnitrile-12-carboxyl-borrelidin (3) were isolated from a plant endophytic Streptomyces sp. NA06554. Their structures were determined by extensive spectroscopic analysis including HRESIMS, 1D and 2D NMR data. The antibacterial activities for compounds 1 – 6 were examined. Borrelidins A (1) and L (6) showed potent and moderate antibacterial activity against Micrococcus luteus , respectively, whereas other derivatives (2 – 5) are almost inactive, which allows us to propose a plausible structure-activity relationship. [ABSTRACT FROM AUTHOR]

Chaetospirolactone (1), a novel spiro-lactone bearing a rare 1-oxaspiro [4.4] non-7-ene-2,6-dione skeleton, and orsellide F (2), together with six known compounds (3-8), were isolated from an endophytic fungus Chaetomium sp. NF00754. Their structures were determined by interpretation of spectroscopic data. The absolute configurations of 1 and 2 were established by analysis of single X-ray crystallographic data and CD spectra. Compounds 3, 4, and 6 showed moderate acetylcholinesterase inhibitory activity with IC50 values of 7.34, 5.19, and 7.67 μM, respectively. [ABSTRACT FROM AUTHOR]

Three new simple trichothecenes, 15-acetyltrichoverrol B ( 3), 13′-acetyltrichoverrin B ( 5), and 6′-dehydroxytrichoverrin B ( 6), along with five known trichothecenes trichodermadienediol B ( 1), trichoverrol B ( 2), trichoverrin B ( 4), and roridins A ( 7) and D ( 8), have been isolated from the liquid culture of Myrothecium roridum (strain no. QB-1). The structures of the new compounds were established by comprehensive analysis of 1D- and 2D-NMR data. All the compounds were evaluated for antifungal activity, only compounds 7 and 8 showed significant antifungal activity against the tested fungi ( MIC ranged from 10 to 5 μg/ml). [ABSTRACT FROM AUTHOR]

Two new tricycloalternarenes I (1) and J (2), together with five known derivatives (3–7), were isolated from the culture of marine fungus Alternaria sp. The structures were elucidated by a combination of spectroscopic approach (1H, 13C NMR, HMBC, COSY, and NOESY) and the low-temperature (100 K) single-crystal X-ray crystallography analysis. The antimicrobial assays of tricycloalternarenes I (1) and J (2) were tested. [ABSTRACT FROM AUTHOR]

A new alkaloid was isolated from the ethyl acetate extract of the culture of a termite-associated Streptomyces koyangensis BY-4. The structure of 1 was elucidated by using MS, NMR, electronic circular dichroism data, and computational approaches. Compound 1 showed weak antimicrobial activities against a panel of test microbes. [ABSTRACT FROM AUTHOR]

Two new α,β-unsaturated γ-lactones, myrolactones A (1) and B (2), were characterized from the culture broth of the Myrothecium sp. IFB-E106 isolated from the roots of Vatica mangachapoi Blauco. The absolute configuration was determined by the computational electronic circular dichroism approach. Myolactone B showed neuraminidase inhibitory activity with the IC50 value of 13.95 μM. [ABSTRACT FROM AUTHOR]

Precursor-fed cultivation of endophytic Chaetomium globosum1C51 afforded nine novel “unnatural” halogenated chaetoglobosins including those with more preferable immunosuppressive activity. [ABSTRACT FROM AUTHOR]