Sappanone A is a homoisoflavonoid with diverse biological activities that has been isolated from the aerial parts of C. pulcherrima, the heartwood of C. sappan, and the stems of H. campechianum. In vitro, sappanone A inhibits 76.2, 59.2, 37.4, and 35.4% of FGFR1, KDR, c-Met, and c-Kit kinase activity, respectively, when used at a concentration of 10 μM. It also inhibits influenza viral neuraminidase (NA) with IC50 values of 0.7, 1.1, and 1 μM for H1N1, H3N2, and H9N2 influenza viral NAs, respectively. Sappanone A has antibacterial activity against Gram-positive B. subtilis, B. sphaericus, and S. aureus as well as Gram-negative K. aerogenes and C. violaceum. It also inhibits the growth of A. niger and C. albicans fungi. Sapannone A inhibits LPS-induced inflammatory responses in vitro and in vivo, reducing nitric oxide (NO), interleukin-6 (IL-6), and prostaglandin E2 (PGE2; ) production in RAW264.7 cells as well as LPS-induced mortality in mice. It also attenuates airway inflammation and mucus hypersecretion via activation of the Nrf2 signaling pathway in a mouse model of ovalbumin-induced asthma.
