Simultaneous quantitative analysis of the active principles and pigments in leaf extracts of Isatis tinctoria by HPLC/UV/MS

Woad (Isatis tinctoria L., Brassicaceae) has been used in Central Europe since antiquity for the treatment of inflammatory disorders [1]. Trypthanthrin (1), linolenic acid (2), and indolin-2-one 3 were shown to be active principles inhibiting COX-2, 5-LOX, the expression of i-NOS, and the release of histamine. Indirubine (4) is a potent inhibitor of CDK5 and GSK-2, and indigo (5) is a side product of indirubine formation. Lipophilic extracts showed anti-inflammatory activity in animals and in a clinical pilot study.

Quantitative data on the pharmacologically active principles is essential in view of a possible develop-ment of phytopharmaceuticals. We developed and validated a HPLC procedure for the quantitative analysis of 1–5. The assay combines ESI⁺, ESI^- and UV detection modes and enables the determination of all compounds in a single HPLC run. The method has been applied to the analysis of extracts obtained by accelerated solvent extraction (ASE) and supercritical fluid extraction.

Reference: 1. Hamburger, M. (2002), Phytochem. Rev. 1: 333–344.