School of Biological Sciences, The University of Hong Kong, Hong Kong, PR China.
Nat Prod Res. 2010 Feb;24(3):206-21. doi: 10.1080/14786410802228827.
The subfamily Asclepiadoideae (Apocynaceae) and the closely-related Periplocoideae are sources of many indigenous Indian medicinal plants. We surveyed antioxidant properties and total phenolic and flavonoid contents of 15 samples, representing 12 Indian medicinal plant species from these subfamilies. Total antioxidant assay was performed using the 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power methods. Total phenolic and flavonoid contents were measured using colourimetric methods. Principal phenolic compounds were detected by liquid chromatography-mass spectrometry (LC-MS). The highest antioxidant capacity and high levels of total phenolics and flavonoids were found in the leaves of Decalepis hamiltonii. The stems of Sarcostemma brevistigma exhibited the highest xanthine oxidase (XO) inhibitory activity. The roots of Hemidesmus indicus showed the highest OH(-) radical scavenging activity. In general, Periplocoideae members exhibited higher antioxidant activity than Asclepiadoideae members. The highly significant and positive correlations (R > 0.914) between total antioxidant capacity parameters and total phenolic content indicated that the phenolic compounds contributed significantly to the antioxidant activity of the tested plant samples. The principal phenolic phytochemicals from these plants were identified by LC-MS, including flavonoids, phenolic acids and phenolic terpenoids. Chlorogenic acid and rutin were detected in almost all of the plant samples. The LC-MS analysis provided full fingerprints of the principal phenolic compounds in the medicinal plants from these two subfamilies, which are useful for their authentication and quality evaluation.
三叶藤亚科（夹竹桃科）和与其密切相关的萝藦亚科是许多印度本土药用植物的来源。我们调查了 15 个样本的抗氧化特性以及总酚和类黄酮含量，这些样本代表了这两个亚科的 12 种印度药用植物物种。使用 2,2-联氮双-3-乙基苯并噻唑啉-6-磺酸和铁还原抗氧化能力法进行总抗氧化测定。使用比色法测定总酚和类黄酮含量。通过液相色谱-质谱（LC-MS）检测主要酚类化合物。在 Decalepis hamiltonii 的叶子中发现了最高的抗氧化能力以及高水平的总酚和类黄酮。Sarcostemma brevistigma 的茎表现出最高的黄嘌呤氧化酶（XO）抑制活性。Hemidesmus indicus 的根表现出最高的 OH(-) 自由基清除活性。一般来说，萝藦亚科成员的抗氧化活性高于三叶藤亚科成员。总抗氧化能力参数与总酚含量之间存在高度显著和正相关（R > 0.914），表明酚类化合物对测试植物样品的抗氧化活性有重要贡献。这些植物的主要酚类植物化学成分通过 LC-MS 鉴定，包括黄酮类、酚酸和酚类萜类。几乎所有的植物样品中都检测到绿原酸和芦丁。LC-MS 分析为这两个亚科的药用植物中的主要酚类化合物提供了完整的指纹图谱，这对它们的鉴定和质量评估很有用。
