Hydroxytyrosyl esters with short, medium and long acyl chains were evaluated for their ability to reduce nitric oxide (NO) production by lipopolysaccharide-stimulated RAW264.7 macrophages. Among the compounds tested, C18 esters, namely hydroxytyrosyl stearate (HtySte) and hydroxytyrosyl oleate (HtyOle), were found to decrease NO production in a concentration-dependent manner, while the other compounds, including the parent hydroxytyrosol, were ineffective in the tested concentration range (0.5–5 μM). Further study of the potential immune-modulating properties of HtyOle revealed a significant and concentration-dependent suppression of prostaglandin E₂ production. At a transcriptional level, HtyOle inhibited the expression of inducible NO synthase, cyclooxygenase-2 and interleukin-1β. Moreover, HtyOle was identified for the first time in olive oil by-products by means of high performance liquid chromatography coupled with mass spectrometry. By contrast, HtyOle was not found in intact olives. Our results suggest that HtyOle is formed during oil processing and represents a significant form in which hydroxytyrosol occurs.

评价了具有短，中和长酰基链的羟基酪氨酸酯减少脂多糖刺激的RAW264.7巨噬细胞减少一氧化氮（NO）产生的能力。在测试的化合物中，发现C18酯，即硬脂酸羟基酪氨酯（HtySte）和油酸羟基酪氨酯（HtyOle），以浓度依赖的方式降低NO的产生，而其他化合物（包括母体羟基酪醇）在测试浓度下无效。范围（0.5-5μM）。对HtyOle潜在的免疫调节特性的进一步研究表明，前列腺素E ₂具有明显的浓度依赖性。生产。在转录水平上，HtyOle抑制诱导型NO合酶，环氧合酶2和白介素1β的表达。此外，通过高效液相色谱-质谱联用，首次在橄榄油副产品中鉴定出HtyOle。相比之下，完整橄榄中未发现HtyOle。我们的结果表明，HtyOle是在石油加工过程中形成的，代表了其中存在羟基酪醇的重要形式。