Dipartimento di Scienze Farmaceutiche, via Ugo Schiff 6, 50019 Sesto Fiorentino, Firenze, Italy.
Talanta. 2011 Jul 15;85(1):167-76. doi: 10.1016/j.talanta.2011.03.050. Epub 2011 Apr 8.
The Rosmarinus officinalis L. is widely known for its numerous applications in the food field but also for the increasing interest in its pharmaceutical properties. Two groups of compounds are mainly responsible for the biological activities of the plant: the volatile fraction and the phenolic constituents. The latter group is mainly constituted by rosmarinic acid, by a flavonoidic fraction and by some diterpenoid compounds structurally derived from the carnosic acid. The aim of our work was to optimize the extractive and analytical procedure for the determination of all the phenolic constituents. Moreover the chemical stability of the main phenols, depending on the storage condition, the different drying procedures and the extraction solvent, have been evaluated. This method allowed to detect up to 29 different constituents at the same time in a relatively short time. The described procedure has the advantage to being able to detect and quantify several classes of compounds, among them numerous minor flavonoids, thus contributing to improving knowledge of the plant. The findings from this study have demonstrated that storing the raw fresh material in the freezer is not appropriate for rosemary, mainly due to the rapid disappearing of the rosmarinic acid during the freezing/thawing process. Regarding the flavonoidic fraction, consistent decrements, were highlighted in the dried samples at room temperature if compared with the fresh leaf. Rosmarinic acid, appeared very sensitive also to mild drying processes. The total diterpenoidic content undergoes to little changes when the leaves are freeze dried or frozen and limited losses are observed working on dried leaves at room temperature. Nevertheless it can be taken in account that this fraction is very sensitive to the water presence during the extraction that favors the conversion of carnosic acid toward it oxidized form carnosol. From our findings, it appear evident that when evaluating the phenolic content in rosemary leaves, several factors, mainly the type of storage, the drying process and the extraction methods, should be carefully taken into account because they can induce partial losses of the antioxidant components.
迷迭香因其在食品领域的众多应用而广为人知，但也因其越来越多的药物特性而受到关注。两类化合物主要负责植物的生物活性：挥发性成分和酚类成分。后者主要由迷迭香酸、类黄酮和一些结构上来源于熊果酸的二萜类化合物组成。我们的工作旨在优化提取和分析方法，以测定所有酚类成分。此外，还评估了主要酚类物质在储存条件、不同干燥程序和提取溶剂下的化学稳定性。该方法允许在相对较短的时间内同时检测到多达 29 种不同的成分。该方法的优点是能够同时检测和定量多种化合物，其中包括许多微量类黄酮，从而有助于提高对植物的认识。这项研究的结果表明，将新鲜原料储存在冰箱中不适合迷迭香，主要是因为在冷冻/解冻过程中迷迭香酸迅速消失。至于类黄酮部分，与新鲜叶片相比，室温下干燥样品中的含量明显下降。迷迭香酸对温和干燥过程也非常敏感。当叶子进行冷冻干燥或冷冻时，总二萜含量几乎没有变化，在室温下处理干燥叶子时，观察到的损失有限。尽管如此，可以考虑到，在提取过程中，该部分非常容易受到水的存在的影响，这有利于熊果酸向其氧化形式熊果酸的转化。从我们的研究结果可以明显看出，在评估迷迭香叶中的酚类含量时，应仔细考虑几个因素，主要是储存类型、干燥过程和提取方法，因为它们可能会导致抗氧化成分的部分损失。
