Antioxidant properties and factors of allspice constituents

本研究的目的是确定多香果成分的结构，并阐明其抗氧化性及其影响因素。在室温下，用正己烷、二氯甲烷和70%丙酮水溶液依次萃取干燥的多香果。从70%丙酮水溶液萃取物中除去丙酮后，将所得含水残余物分离成二氯甲烷可溶性、乙酸乙酯可溶性和水溶性级分。采用重复色谱法对乙酸乙酯萃取物进行分离纯化，得到20个化合物，其中包括2个苯丙素类化合物、11个黄酮类化合物和7个没食子酸类化合物。根据光谱数据鉴定了它们的结构。其中，五个是新的，十五个是已知的。然而，有10种已知化合物是首次从多香果中分离出来的。日 关于我们 用几种不同的方法评价了这些分离的化合物以及我们实验室已经分离的17种化合物的抗氧化性能。清除DPPH自由基的活性与邻苯二酚的数量有关。含1，2，3-三羟基的化合物清除超氧阴离子自由基的能力强于含1，2-二羟基的化合物。邻苯二酚结构对亚油酸甲酯在本体体系中的自氧化具有抑制作用。在90 ℃下测定时，单宁和黄酮苷等高极性化合物表现出微弱的活性，表明它们在90 ℃下的本体活性可能受到底物油亲和性的影响。在40 ℃下测量时未观察到这种现象。单宁对AAPH诱导的脂质体氧化有很强的抑制作用。在类黄酮的情况下，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种多香果成分对调味料在20 ℃下自氧化的抑制作用。活性顺序与清除DPPH活性顺序一致，受试化合物的极性不影响活性。结果表明，多香果中具有邻苯二酚结构的化合物具有较强的抗氧化作用，其抗氧化活性可能与自由基清除能力和极性有关。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