Molecular Networking-based De-replication Strategy Leads to the Isolation of a New Chromone from Pleosporales sp

A new chromone analogue (1) was isolated from an EtOAc-extract of Pleosporales sp. culture medium, together with five known chromones (2 – 6). The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The chemical structure of the new compound was elucidated using NMR and MS spectroscopy, and the absolute configuration was established by the Mosher's method. All isolated compounds were evaluated for their inhibitory effects on lipopolysaccharide-induced nitirc oxide production in RAW 264.7 macrophages. Compound 1 showed marginal inhibitory activity with an IC50 value of 118.7 μM.

Molecular Networking-based De-replication Strategy Leads to the Isolation of a New Chromone from Pleosporales sp

A new chromone analogue (1) was isolated from an EtOAc-extract of Pleosporales sp. culture medium, together with five known chromones (2 – 6). The isolation workflow was guided by a Molecular Networking-based dereplication strategy. The chemical structure of the new compound was elucidated using NMR and MS spectroscopy, and the absolute configuration was established by the Mosher's method. All isolated compounds were evaluated for their inhibitory effects on lipopolysaccharide-induced nitirc oxide production in RAW 264.7 macrophages. Compound 1 showed marginal inhibitory activity with an IC50 value of 118.7 μM.

Nitric Oxide Inhibitory Constituents from the Fruits of Amomum tsao-ko

Bioactivity-guided fractionation of MeOH extract of the dried fruits of Amomum tsao-ko led to isolation of nine compounds (1 – 9). Their structures were elucidated by spectroscopic methods including extensive 1D and 2D-NMR, as alpinetin (1), naringenin-5-O-methyl ether (2), naringenin (3), hesperetin (4), 2′,4′,6′-trihydroxy-4-methoxy chalcone (5), tsaokoin (6), boesenbergin B (7), 4-hydroxyboesenbergin B (8), and tsaokoarylone (9). Of these, compound 8 was isolated from a natural source for the first time, which was previously reported as a synthetic product. The isolated compounds (1 – 9) were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Among them, three chalcone derivatives (compounds 5, 7, and 8) and a diarylheptanoid (compound 9) exhibited significant inhibitory activity on the NO production with IC₅₀ values ranging from 10.9 to 22.5 µM.