Sydowinin B is a xanthone polyketide that has been found inA. sydowiiand has immunosuppressant activity.¹It inhibits LPS- or concanavalin A-induced proliferation of isolated mouse splenic lymphocytes (IC₅₀s = 19.2 and 20.8 µg/ml, respectively).²Sydowinin B inhibits superoxide generation in, and elastase release from, isolated human neutrophils induced by cytochalasin B and N-Formyl-Met-Leu-Phe with IC₅₀values of 21.2 and 12.62 µM, respectively.³

1.Hamasaki, T., Sato, Y., and Hatsuda, Y.Structure of sydowinin A, sydowinin B, and sydowinol, metabolites from Aspergillus sydowiAgr. Biol. Chem.39(12)2341-2345(1975) 2.Liu, H., Chen, S., Liu, W., et al.Polyketides with immunosuppressive activities from mangrove endophytic fungus Penicillium sp. ZJ-SY2Mar. Drugs14(12)217(2016) 3.Chung, Y.-M., Wei, C.-K., Chuang, D.-W., et al.An epigenetic modifier enhances the production of anti-diabetic and anti-inflammatory sesquiterpenoids from Aspergillus sydowiiBioorg. Med. Chem.21(13)3866-3872(2013)