Identification and quantification of polyphenols from Cassia auriculata L leaf, flower and flower bud using UPLC-QqQ-MS/MS

<p><i>Cassia auriculata</i> is an Ayurvedic medicinal herb, traditionally indicated for diabetes and hyperlipidemia. Several works have demonstrated its antioxidant, antidiabetic and anti-hyperlipidemic activity <i>in vivo</i> and <i>in vitro</i>. Nevertheless, only a few works have investigated its phytochemical composition, and specifically, the polyphenolic composition of the various plant parts that are traditionally used. In this work, the polyphenolic composition of <i>C. auriculata</i> leaves, flowers and flower buds were evaluated using UPLC-QqQ-MS/MS. Our results demonstrated the polyphenolic profile of <i>C. auriculata</i> plant parts. A total of five benzoic acids, four hydroxycinnamic acids, three flavonoids and two other phenolic compounds were identified and quantified. Our results show that in <i>C. auriculata</i> leaves, flavonoids were most abundant (4204 µg/g DW), while in flowers benzoic acids were the most prominent (3924 µg/g DW). Total benzoic acid contents ranged from 1580 to 3924 µg/g DW in leaf and flower, respectively. Hydroxycinnamic acids ranged from 404 µg/g DW in flower buds to 2623 µg/g DW in leaves. Flavonoids showed the highest contents in leaves, while the lowest levels were observed in flowers (2626 µg/g DW). The meaning of the results is discussed in light of the bioactivities of phenolic compounds, concomitant with <i>C. auriculata</i> reported medicinal bioactivities. To our knowledge, this is the first work to identify and quantify polyphenolic compounds in flower and bud of <i>C. auriculata</i>. </p>