Abstract
Taxane standard solutions and Taxus sp. extracts were analyzed with comprehensive two-dimensional liquid chromatography (LC×LC) using the Agilent 1290 Infinity 2D-LC solution with DAD and MS detection. Reversed-phase liquid chromatography was applied in both the first and second dimension. Orthogonality was achieved by using different column chemistries and mobile phases. Qualitative and quantitative aspects of the method were investigated and tested with real samples.


Introduction
Taxanes are a group of diterpenes useful in cancer treatments because of their mitotic inhibitory activity1. Taxol (Paclitaxel) shows good antitumor activity and is used in the treatment of breast and lung cancers. It is one of the best chemotherapeutics developed from plant sources2. It was first isolated from the bark of Taxus brevifolia (Pacific yew tree) in 19711. The paclitaxel content of the bark is low; therefore, attempts have been made to synthesize the product. The synthesis proved to be possible, but diffi cult, and not commercially interesting3. At present, semisynthesis from more abundant precursors (10-Deacetylbaccatin-III, Baccatin-III, and Cephalomannine) and plant cell fermentation are the main sources of therapeutic paclitaxel4.
The analysis of the taxane content of various species of yew trees is important for selection of the correct type and growing conditions. Taxanes are generally analyzed by (U)HPLC and LC/MS, and their separation is challenging. Analyzing these compounds in a complex matrix such as Taxus sp. extracts is even more difficult due to the lack of peak capacity in a one dimensional system. The matrix constituents interfere with detection and quantitation of the target compounds. An efficient way to increase peak capacity significantly is to perform comprehensive two-dimensional liquid chromatography (LC×LC). This Application Note presents data on the analysis of taxanes with the Agilent 1290 Infinity 2D-LC solution. On-line mass spectroscopic detection was additionally employed with 2D-LC to confirmation of the identity of detected taxanes in Taxus sp. extracts.