Conjugation of Glucaric Acid in Comparison to Quinic Acid by Caffeic Acid Allows for Enhanced Metabolite Diversification in Bush Tea (Athrixia phylicoides DC.) Extracts Post UV Light Exposure

Abstract

　The cultivation of bush tea (Athrixia phylicoides DC.) has been shown to be affected by light availability which has encouraged the use of different net shading to filter the amount of light on the plant. The objective of this study was to enhance the levels of caffeoyl-D-glucaric acid derivatives through UV induced geometrical isomerization. Bush tea methanolic leaf extracts were placed under UV light lamp at 254 nm for the duration of 24 h and new metabolites which formed due to UV exposure were detected through ultra-high-liquid chromatography quadrupole time-of-fight mass spectrometry (UHPLC-QTOF-MS). Hydroxyl-cinnamic acids (HCAs) derivatives have been shown to undergo photoisomerization during post ultra-violet (UV) light exposure, evidenced by the emergence of photo-isomers.