Efficient Heated Ultrasound Assisted Extraction and Clean-Up Method for Quantifying Paclitaxel Concentrations in Taxus Wallichiana

ABSTRACT

A simple method was developed using heated ultrasound-assisted extraction (UAE) with ethanol and an ENVI-Carb clean-up step for quantifying paclitaxel from various parts (leaf, stem, bark and roots) of T. wallichiana with standard liquid chromatography using a Waters Novapak Phenyl column with ultraviolet detection (HPLC-UV). Method effectiveness and accuracy were evaluated by quantifying paclitaxel independently in multiple sequential extractions, comparing HPLC-UV quantitation with quadrapole time-of-flight mass spectrometry (QToF/MS) time-of-flight to confirm the adequacy of HPLC-UV and assessing the use of docetaxel as a paclitaxel surrogate. Nearly identical trends for % recovered with each sequential extract was observed for both compounds. ENVI-Carb clean-up removed most of the colours in the extract, did not affect the recovery of paclitaxel or docetaxel in the presence of the sample matrix, and minimised compounds that may interfere with paclitaxel quantitation. For both docetaxel and paclitaxel, most of the mass was extracted in the first two extractions with 93.1% ± 4.4% and 92.6% ± 3.9%, respectively. The mass sum recovered in the first three extractions was similar to analysis of the combined extracts with 95–99% extracted relative to the total recovered from four sequential extractions. Paclitaxel concentrations in ENVI-Carb cleaned extracts were similar between HPLC-UV and uPLC-ToF/MS (using the 551 product ion) supporting the reliability of the method. The similar recovery trend between docetaxel and paclitaxel indicates that extractions could be limited to a single step if docetaxel is used to correct for recovery.

KEYWORDS:

• Ethanol
• ENVI-Carb
• HPLC-UV
• uPLC-ToF/MS
• docetaxel

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by the Higher Education Commission (HEC) of Pakistan under the International Research Support Initiative Program (IRSIP) and the USDA National Institute of Food and Agriculture Hatch Funds [Accession No. 1006516].