Flavonoid Content Assay: Prevalidation and Application on Plantago L. Species

Renata Jurišić Grubešić^a, Jadranka Vuković^a*, Dario Kremer^b, Sanda Vladimir-Knežević^c

^a Department of Analytics and Control of Medicines, Faculty of Pharmacy and Biochemistry,
University of Zagreb, A. Kovačića 1, HR-10000 Zagreb, Croatia
^b Department of Pharmaceutical Botany, Faculty of Pharmacy and Biochemistry,
University of Zagreb, A. Kovačića 1, HR-10000 Zagreb, Croatia
^c Department of Pharmacognosy, Faculty of Pharmacy and Biochemistry,
University of Zagreb, Marulićev trg 20, HR-10000 Zagreb, Croatia
E-mail: jadranka@pharma.hr;
Tel/Fax: +385 1 49 200 89

Abstract
This work is aimed to prevalidate and apply UV/Vis spectrophotometric procedure for flavonoid determination in herbal material using AlCl₃ as a reagent. Fast and simple, full prevalidation for quality control and standardization of analytical procedure, based on mathematical/statistical testing coupled with system of diagnosis was used to evaluate and demonstrate the reliability of method for flavonoid determination with AlCl₃ (F–Al procedure). Favourable prevalidation characteristics verified this procedure as a valuable tool in flavonoid analysis, so it was successfully applied for determination of flavonoids in leaves, stems and flowers of Plantago L. species growing in Croatia. The results showed the various flavonoid contents between different plant parts (leaves: up to 0.13%; stems: up to 0.07% and flowers: up to 0.07%). The results of flavonoid determination were statistically evaluated by using Principal Component Analysis (PCA) and Student’s t-test as a contribution to investigation of different taxa of genus Plantago L.

Keywords: Prevalidation strategy, flavonoids, aluminium chloride, Plantago L.