Antioxidant properties and factors of allspice constituents

本研究旨在确定所有香料成分的结构，阐明它们的抗氧化性能以及影响抗氧化活性的因素。用正己烷、二氯甲烷和70%丙酮水溶液在室温下连续提取干香料。从70%的丙酮水萃取物中除去丙酮后，得到的水基残留物被分离成可溶于二氯甲烷、可溶于乙酸乙酯和可溶于水的馏分。采用重复层析技术对具有较强DPPH自由基清除活性和对亚油酸甲酯自氧化反应有较强抑制作用的乙酸乙酯可溶部分进行纯化，得到20个化合物，包括2个苯丙烷类化合物、11个黄酮类化合物和7个没食子酸相关化合物。根据一些波谱数据确定了它们的结构。其中5个为新种，15个为已知种。然而，首次从多香料中分离得到10个已知化合物。TH…用几种不同的方法对这些分离的化合物以及我们实验室已经分离的17个化合物的抗氧化性能进行了评价。邻苯二酚对DPPH自由基的清除作用依赖于邻二酚的数量。含1，2，3-三羟基苯基的化合物对O_2~(2+)的清除能力强于含1，2-二羟基苯基的化合物。邻二酚结构有助于抑制亚油酸甲酯在本体体系中的自氧化反应。在90℃下测定时，单宁和黄酮苷等高极性化合物的活性较弱，这表明与底物油的亲和力可能对它们在90℃时的整体体系活性有一定影响。在40℃下测量时未观察到这种现象。单宁对AAPH诱导的脂质体氧化表现出很强的活性。在黄酮类化合物中，槲皮素相关化合物显示出比杨梅素相关化合物更强的活性。此外，还测定了6种全香成分在20℃时对敷料自氧化的抑制作用。活性顺序与对DPPH的清除活性顺序一致，在这种情况下，被试化合物的极性不影响活性。综上所述，具有邻二酚结构的化合物有助于Alspice的抗氧化作用，其抗氧化性能可能与其清除自由基的能力和极性有关。较少

This study was aimed to determine the structures of allspice constituents and elucidate their antioxidant properties as well as the factors of antioxidant activity. Dried allspice was successively extracted with n-hexane, dichloromethane and 70% aqueous acetone at room temperature. After removing acetone from the 70% aqueous acetone extract, the resulting aqueous residue was separated into the dichloromethane-soluble, ethyl acetate-soluble and water-soluble fractions. The ethyl acetate-soluble fraction which showed a strong DPPH radical scavenging activity and a high inhibitory effect on the autoxidation of methyl linoleate in bulk system was purified using repeated chromatographic techniques to give twenty compounds including two phenylpropanoids, eleven flavonoids and seven gallic acid related compounds. Their structures were elucidated on the basis of some spectral data. Among them, five are new and fifteen are known. However ten known compounds were first isolated from allspice. Th … More e antioxidant properties of these isolated compounds together with seventeen compounds which have been already isolated in our laboratory were evaluated using several different methods. The DPPH radical scavenging activity was dependent on the number of ortho-diphenols. The O_2^- radical scavenging activity of compounds with 1,2,3-trihydroxyphenyl groups is stronger than that of compounds with 1,2-dihydroxyphenyl groups. Ortho-diphenol structure was contributed to the inhibitory effects on autoxidation of methyl linoleate in bulk system. When measured at 90℃, the high polar compounds such as tannin and flavonoid glycosides showed slight activity, which suggested that affinity to substrate oil might have some influence on their activity in bulk system at 90℃. Such phenomenon was not observed when measured at 40℃. Tannin showed very strong activity toward liposome oxidation induced by AAPH. In the case of flavonoid, quercetin related compounds showed stronger activity than myricetin related compounds. In addition, the inhibitory effects of six allspice constituents on the autoxidation of dressing at 20℃ were measured. The activity order was consistent with the scavenging activity order against DPPH and in this case the polarity of tested compounds did not influence the activity. In conclusion, compounds with ortho-diphenol structure contributed to the antioxidant effect of allspice, and their antioxidant properties might be governed by their radical scavenging abilities and polarities. Less