Chemical Constituents of Impatiens balsamina Stems and Their Biological Activities

The purification of the MeOH extract from Impatiens basamina by repeated column chromatography led to the isolation of one new tetrahydronaphthalene (1), together with eleven known compounds (2 - 12). The structure of the new compound (1) was determined by spectral data analysis ($^1H$ and $^{13}C$-NMR, $^1H-^1H$ COSY, HSQC, HMBC, NOESY, and HR-ESI-MS). Isolated compounds (1 - 12) were evaluated for their inhibitory effects on NO production in LPS-activated murine microglial BV-2 cells and their effects on NGF secretion from C6 glioma cells. Compounds 3, 7, and 10 reduced NO levels in LPS-activated murine microglial cells with $IC_{50}$ values of 26.89, 25.59, and $44.21{\mu}M$, respectively. Compounds 1, 5, and 9 upregulated NGF secretion to $153.09{\pm}4.66$, $156.88{\pm}8.86$, and $157.34{\pm}3.30%$, respectively.