title: Development of a simple chromatographic method for distinguishing between two easily confused species, Hedyotis diffusa and Hedyotis corymbosa.
abstract: Hedyotis diffusa Willd. and Hedyotis corymbosa (L.) Lam. are closely related species of Rubiaceae family and they can be easily confused. Although previous reports have been found in which ultraviolet spectrum, convolution spectrometry or X-ray diffraction are reported to be used for distinguishing between the two species, these methods require specialised equipment. Hence, this study aims to develop a simple chromatographic method for the purpose. Our results illustrate the use of a thin-layer chromatographic (TLC) profile to differentiate between the two species, with a blue zone appearing at around an R(f)  of 0.36 in H. corymbosa but not in H. diffusa. The compound corresponding to this blue zone was later found to be hedyotiscone A. LC-MS with multiple reaction monitoring was used as a tool to identify and quantify hedyotiscone A in the test samples. In conclusion, a quick and simple TLC assay was conducted to distinguish between the two species H. diffusa and H. corymbosa.
authors: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong. claralau@cuhk.edu.hk
authors: Clara B S
authors: CB
authors: Lau
authors: Ling
authors: L
authors: Cheng
authors: Bobby W H
authors: BW
authors: Cheng
authors: Grace G L
authors: GG
authors: Yue
authors: Eric C W
authors: EC
authors: Wong
authors: Ching-Po
authors: CP
authors: Lau
authors: Ping-Chung
authors: PC
authors: Leung
authors: Kwok-Pui
authors: KP
authors: Fung
mesh_terms: D002855:Chromatography, Thin Layer / Q000379:methods*; D011564:Furocoumarins; D032064:Hedyotis / Q000737:chemistry* / Q000145:classification*
chemical_list: D011564:Furocoumarins; C509726:hedyotiscone A