A direct current (DC) polarographic assay based on the decrease of anodic current of HydroxoPerhydroxoMercury (II) Complex (HPMC) formation in H₂O₂ solution in Clark Lubs (CL) buffer (pH 9.8) as working solution was previously applied to determine antioxidant (AO) capacity of water‐soluble compounds. Here, the applicability of HPMC assay was extended into samples poorly soluble in water such as the essential oils and extracts of Lamiaceae and Apiaceae species obtained by ultrasound‐assisted maceration (UAM) and Soxhlet extraction (SE) with 70 and 96% ethanol as well as individual compounds present. The influence of solvents miscible with water on HPMC anodic current was studied, and working solution was optimized. A modified HPMC method was applied to measure AO capacity of essential oils and extracts as well as compounds identified using gas chromatography‐mass spectrometer (GC‐MS) and gas chromatography with flame‐ionization detection (GC‐FID) (terpenoids and catechols) or known to be present (phenolic acids and flavonoids). A 1:1 mixture of CL buffer and ethanol was chosen as working solution. AO capacity of essential oils and extracts, established by modified HPMC assay, was in range of 1.2‐2.0 and 9.2‐38.4 (%/mL) while terpenoids and phenolics in range of 0.1‐0.5 and 13.5‐38.5 (%/mol), respectively. The superior AO capacity was ascribed to essential oils and extracts of Lamiaceae species and to extracts obtained with 70% ethanol. A higher AO capacity of extracts in comparison to essential oils was corroborated with a difference in phenolics and terpenoids capacity.

中文翻译：

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直流极谱抗氧化剂测定方法的改进—在芳香植物中的应用及其活性原理

以前曾采用过氢极性过氧化汞（II）络合物（HPMC）在Clark Lubs（CL）缓冲液（pH 9.8）作为溶液的H ₂ O ₂溶液中形成的阳极电流减少的直流（DC）极谱测定法来确定水溶性化合物的抗氧化（AO）能力。在这里，HPMC测定法的适用性扩展到了难溶于水的样品中，例如精油以及唇形科和唇形科的提取物。通过超声浸软（UAM）和索氏提取（SE）并用70％和96％的乙醇以及存在的单个化合物获得的物种。研究了与水混溶的溶剂对HPMC阳极电流的影响，并优化了工作溶液。改进的HPMC方法用于测量精油和提取物以及使用气相色谱-质谱仪（GC-MS）和带火焰离子化检测的气相色谱仪（GC-FID）（萜类和儿茶酚）鉴定的化合物的AO容量，或者已知存在（酚酸和类黄酮）。选择CL缓冲液和乙醇的1：1混合物作为工作溶液。通过改进的HPMC分析确定的精油和提取物的AO容量在1.2-2.0和9.2-38.4（％/ mL）之间，而萜类和酚类的AO容量在0.1-0.5和13.5-38.5（％/ mol）之间，分别。优异的AO容量归因于香精油和提取物唇形科物种，并以70％乙醇提取。与酚精和萜类化合物的能力相比，证实了与精油相比，提取物具有更高的AO能力。