I try to determine the total content of flavonoids from various plant extracts by Pharmacopeial method (spectrophotometric). In some cases, when the aluminium chloride is added, a precipitate occurs with the discoloration of the solution. Has anyone ever faced this problem?
Total flavonoids, limonoids you can determine using RP-HPLC. You used Spectrophotometry for the purpose and must have done it after development of calibration curve on identifying absorption maximum separately. Aluminium chloride can rob the charges carried by the analyte as well as forms sticky and adherent ppt which entraps within it various ingredients in suspension or colloidal form including colour imparting ones if any hence the discoloration as referred by you.
I follow a protocol according the article titled: Amorim, E.L.C.; Nascimento, J.E.; Monteiro, M.J.; Sobrinho, T.J.S.P.; Araújo, T.A.S.; Albuquerque, U.P. A simple and accurate procedure for the determination of tannin and flavonoid levels and some applications in ethnobotany and ethnopharmacology. Functional Ecosystems and Communities. 2008. P. 88-94'. It's available here in the researchgate in open access.
You can calculated according to the method ( Peixoto S., Silva C., Nascimento J.,Albuquerque U. and Amorim E. (2008).
Braz J Pharm Sci., 44,p.683-689.
you can tary to fallow Determination of total phenolic content
Total phenolic content was evaluated with Folin–
Ciocalteu’s phenol reagent10. 100 μL of sample
extracts (1 mg each dissolved in 1 mL DMSO,
1mg/mL) was taken for the assay and Gallic acid was
taken as standard. All determinations were carried out
in three replications.Rawat, S., Bhatt, I.D., Rawal, R.S. Variation in total phenolic content and antioxidant potential of Hedychium spicatum Buch. Ham. ex D. Don in west Himalaya, India. Journal of Food
Composition and Analysis 2011, 24, 574–579. please find the atttached file for your kind inormtion
- Badges
- Science topic
- Similar topics
- Biological Science
- Botany
- Pharmaceutical Botany
- Plant Extracts