Chemical Fingerprinting Profile and Targeted Quantitative Analysis of Phenolic Compounds from Rooibos Tea (<i>Aspalathus linearis)</i> and Dietary Supplements Using UHPLC-PDA-MS
Omer I. Fantoukh,
Yan-Hong Wang,
Abidah Parveen,
Mohammed F. Hawwal,
Zulfiqar Ali,
Gadah A. Al-Hamoud,
Amar G. Chittiboyina,
Elizabeth Joubert,
Alvaro Viljoen,
Ikhlas A. Khan
Affiliations
Omer I. Fantoukh
Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Yan-Hong Wang
National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Abidah Parveen
Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Mohammed F. Hawwal
Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
Zulfiqar Ali
National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Gadah A. Al-Hamoud
Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
Amar G. Chittiboyina
National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Elizabeth Joubert
Plant Bioactives Group, Post-Harvest & Agro-Processing Technologies, Agricultural Research Council (Infruitec-Nietvoorbij), Private Bag X5026, Stellenbosch 7599, South Africa
Alvaro Viljoen
Department of Pharmaceutical Sciences and SAMRC Herbal Drugs Research Unit, Tshwane University of Technology, Pretoria 0183, South Africa
Ikhlas A. Khan
Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Aspalathus linearis (Burm.f.) R. Dahlgren, commonly known as rooibos tea, was consumed traditionally by the indigenous South African inhabitants as an herbal remedy. Beside antioxidant properties, it displays antiallergic, antispasmodic, and hypoglycemic activities. An ultra-high-performance liquid chromatography method coupled with photodiode array and mass spectrometry detectors were developed for the determination of 14 phenolic constituents from leaves and stems of A. linearis. The efficient separation was performed within 30 min at a temperature of 30 °C by using C-18 column as the stationary phase and water/acetonitrile with 0.05% formic acid as the mobile phase. Method validation for linearity, repeatability, limits of detection, and limits of quantification was achieved. The limits of detection from 0.2–1 μg/mL were reported for the standard compounds. Their total content varied substantially (1.50–9.85 mg/100 mg sample) in 21 dietary supplements. The presence of regioisomers and diastereomers which co-elute on a variety of stationary phases make separation for quantification purposes challenging. This method was found to be efficient in providing low retention times and excellent resolution for this type of phytochemicals. The established method is suitable for chemical fingerprint analysis of A. linearis and cost-effective for quality control of rooibos tea products.