title: Uzara - A quality control perspective of Xysmalobium undulatum.
abstract: BACKGROUND
  Xysmalobium undulatum (L.) Aiton f var. (Asclepiadaceae), commonly known as uzara, is an ethnomedicinally important plant from southern Africa used to treat a variety of ailments. In addition to local use in African Traditional Medicine (ATM), formulations containing uzara have been successfully marketed by a number of pharmaceutical companies. Despite its commercialization, published adequate quality control (QC) protocols are lacking.
  
  
  OBJECTIVE
  The study was conducted to develop QC protocols for uzara based on chromatographic and spectroscopic techniques.
  
  
  METHODS
  High performance thin layer chromatography (HPTLC) and liquid chromatography coupled to mass spectrometry (LC-MS) were used to develop phytochemical fingerprints of ethanolic root extracts of 47 uzara samples collected from eight distinct localities in South Africa. Mid-infrared (MIR) spectroscopy was also explored as a suitable alternative technique for rapid and economic quantification of uzarin.
  
  
  RESULTS
  Adequate chromatographic profiles were obtained using both HPTLC and LC-MS analyses. The chromatographic patterns showed qualitative similarities among plants collected from different locations. The levels of uzarin, the major constituent of uzara, were highly variable between locations, ranging from 17.8 to 139.9 mg/g (dry weight). A good coefficient of determination (R(2 )= 0.939) and low root mean square error of prediction (RMSEP = 7.9 mg/g) confirmed the accuracy of using MIR-PLS calibration models for the quantification of uzarin.
  
  
  CONCLUSIONS
  Both HPTLC and LC-MS can be used as tools in developing quality control procedures for uzara. MIR in combination with chemometrics provides a fast alternative method for the quantification of uzarin.
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .
authors.forename: Sowesa
authors.initials: S
authors.lastname: Kanama
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .|b SAMRC Herbal Drugs Research Unit, Faculty of Science, Tshwane University of Technology , Pretoria , South Africa , and.|c Department of Pharmaceutics and Industrial Pharmacy , Faculty of Pharmacy, King Abdulaziz University , Jeddah , Saudi Arabia.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Viljoen
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .
authors.forename: Gill
authors.initials: G
authors.lastname: Enslin
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .
authors.forename: Guy
authors.initials: G
authors.lastname: Kamatou
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .
authors.forename: Weiyang
authors.initials: W
authors.lastname: Chen
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .
authors.forename: Maxleene
authors.initials: M
authors.lastname: Sandasi
authors.affiliation: a Department of Pharmaceutical Sciences , Faculty of Science, Tshwane University of Technology , Pretoria , South Africa .
authors.forename: Thomas
authors.initials: T
authors.lastname: Idowu
mesh_terms: D029062:Apocynaceae / Q000737:chemistry* / Q000145:classification; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D013058:Mass Spectrometry; D008517:Phytotherapy; D010936:Plant Extracts / Q000032:analysis* / Q000145:classification / Q000592:standards; D018517:Plant Roots; D010946:Plants, Medicinal; D011786:Quality Control; D012015:Reference Standards; D013055:Spectrophotometry, Infrared
chemical_list: D010936:Plant Extracts
keywords: Chemometrics; HPTLC; LC-MS; MIR spectroscopy; uzarin