Abstract
As a contribution towards a better understanding of phenolic variation in the genus Cyclopia (honeybush tea), a collection of 82 samples from 15 of the 23 known species was analysed using liquid-chromatography–high resolution mass spectrometry (UPLC-HRMS) in electrospray ionization (ESI) negative mode. Mangiferin and isomangiferin were found to be the main compounds detected in most samples, with the exception of C. bowiena and C. buxifolia where none of these compounds were detected. These xanthones were found to be absent from the seeds and also illustrated consistent differences between species and provenances. Results for contemporary samples agreed closely with those based on analysis of a collection of ca. 30-year-old samples. The use of multivariate tools allowed for graphical visualizations of the patterns of variation as well as the levels of the main phenolic compounds. Exclusion of mangiferin and citric acid from the data was found to give better visual separation between species. The use of UPLC-HRMS generated a large dataset that allowed for comparisons between species, provenances and plant parts (leaves, pods, flowers and seeds). Phenetic analyses resulted in groupings of samples that were partly congruent with species but not with morphological groupings within the genus. Although different provenances of the same species were sometimes found to be very variable, Principle Component Analysis (PCA) indicated that a combination of compounds have some (albeit limited) potential as diagnostic characters at species level. 74 Phenolic compounds are presented, many of which were identified for the first time in Cyclopia species, with nine of these being responsible for the separation between samples in the PCAs.
Highlights
Cyclopia Vent. is a fynbos-endemic genus of legumes comprising 23 known species
The tentative identification of compounds was based on previous papers [16,17,18,19,20,21,22,23,24,25,26], as well as a combination of fragmentation data, elemental composition based on accurate mass, relative retention times and
The results suggest that phenolic compounds do have diagnostic value in distinguishing random quantitative combinations of main compounds in leaf samples of all the species are shown in between some of the species, especially when combinations of some of the compounds are used
Summary
Cyclopia Vent. is a fynbos-endemic genus of legumes (family Fabaceae, tribe Podalyrieae) comprising 23 known species. But it is only recently that commercial crop and product development has been initiated [2,3], focused mainly on C. genistoides (L.) R.Br., C. intermedia E.Mey. and C. subternata Vogel. As part of a broader chemosystematic study of Cape genistoid legumes, reviewed in 2003 [9], an attempt was made to compare Cyclopia with other genera of the tribe Podalyrieae. Another study [15] showed that butein, 3’hydroxydaidzein and other flavonoids are the main seed metabolites, in Cyclopia and in other genera of the tribe. It was decided to reinvestigate Cyclopia species with the aim of describing the phenolic variation in the genus (which is relevant to developing better quality control analyses) and to have another attempt at evaluating the chemosystematic significance of the main phenolic compounds. The aim was to determine if different species and populations of Cyclopia could be distinguished by quantitative and perhaps qualitative differences in their overall phenolic profiles
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
