Chemical investigation on fermented products by the fungal strain Westerdykella dispersa Ca4–13 isolated from edible oysters Crassostrea angulata collected from Taiwan resulted in the isolation of seven chemical entities. Their structures were elucidated by spectroscopic analysis to be westeroic acid A (1), westeroic acid B (2), westeroic acid C (3), auranticin A (4), auranticin B (5), pilobolusone C (6), and epi-radicinol (7). Among these, westeroic acid A (1) is a novel C14 polyketide with a γ-lactone functionality, while westeroic acids B (2) and C (3) are two rare C28 polyketides with a unique 6/6-spiro-linked δ-lactone moiety. Compounds 1, 2, 3, and 7 exhibited anti-inflammatory activities on nitric oxide production in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 9.9 to 11.3 μM. Compounds 2 and 3 significantly suppressed LPS-induced inducible nitric oxide synthase (iNOS) protein expression. Molecular docking analysis using murine iNOS (PDB ID: 1QW4) provided structural insight into these observations, suggesting that effective inhibition was associated with cooperative interaction networks within the l-arginine binding pocket rather than a single dominant interaction. Overall, these findings highlight their promise as potential lead compounds for further neuroinflammation-related drug development.
Huang et al. (Thu,) studied this question.