Phenylpropanoid ester from Zingiber officinale and their inhibitory effects on the production of nitric oxide

A new phenylpropanoid ester mixture, (E)-geranylferulic acid (1a) and (Z)-geranylferulic acid (1b), along with 13 known compounds, [6]-gingerol (2), [8]-gingerol (3), [10]-gingerdione (4), 1-dehydro-[6]-gingerdione (5), 1-dehydro-[8]-gingerdione (6), [6]-paradol (7), [8]-paradol (8), [6]-gingeroldiacetate (9), 6-hydroxy-[6]-shogaol (10), galanolactone (11), trans-®-sesquiphellandrol (12), trans-sesquipiperitol (13), and 4α,5β-dihydroxybisabola-2,10-diene (14) were isolated from ethanol extract of Zingiber officinale. Their structures were determined based on the spectroscopic (1D, 2D-NMR and MS) and chemical evidence. All of the isolates were evaluated for their potential to inhibit LPS-induced production of nitric oxide in murine macrophage RAW264.7 cells. Compounds 1-12 were found to inhibit nitric oxide production with IC(50) values ranging from 5.5 to 28.5 μM.