Mass spectrometric elucidation of polyphenol constituents in Vernonia amygdalina Del.

7th Edition of International Conference on Pharmacognosy and Medicinal Plants
March 11-12, 2019 London, UK

Soleya Dagnon, Dimitar Bojilov, Zlatomira Novkova, Paraskev Nedialkov and Kristian Kouassi

University Paisii Hilendarski, Bulgaria Medical University of Sofia, Bulgaria Nangui Abrogoua University, Cote d��?Ivoire

Posters & Accepted Abstracts: Am J Ethnomed

DOI: 10.21767/2348-9502-C1-009

Abstract

Vernonia amygdalina Del. (VA), family Asteraceae is a well-known shrub in tropical countries because of its nutritive and medicinal properties. The antioxidant and anticancer therapeutic effects of VA were related to polyphenol content. For this purpose, mass spectrometric investigation was conducted aiming at characterizing the polyphenol composition of Vernonia amygdalina. Previous publications on the polyphenol constituents in VA raise some questions on the component composition caused by inadequacy of the data. It seems necessary to prove the presence of luteolin 7-O-glycosides and the aglycone luteolin. Monocaffeoyl-, dicaffeoyl- and tricaffeoylquinic acids, as well as, feruloyldicaffeoylquinic acid were also reported. In this study the polyphenols were extracted using methanol in an ultrasound bath for 40 min at room temperature (25°C). The extract was evaporated to dryness, resolved in water and divided into chloroform fraction and ethyl acetate fraction. The compounds in both the fractions were characterized by HPLC-PDA. Structural elucidation was performed on Orbitrap UHPLC mass spectrometer. Two flavone aglycones luteolin and apigenin were identified in the chloroform fraction. In the ethyl acetate fraction six flavone glycosides luteolin 7-O-glucoside, luteolin 7-O-glucuronide, luteolin 4’-O-glucoside, apigenin 7-O-rutinoside, apigenin 7-O-glucoside and apigenin 7-O-glucuronide were found, as well as mono and dicaffeoylquinic acids and feruloylquinic acid-Oglycoside. The caffeoylquinic acids (chlorogenic 1,5-3,5 and 4,5-dicaffeoylquinic acids), luteolin 7-O-glucoside, luteolin 7-O-glucuronide and luteolin are the main compounds composing the polyphenol complex of VA. The largest percentage of them was due to 1,5 and 3,5 dicaffeoylquinic acids. Furthermore, the presence of luteolin 4’-O-glucoside, apigenin 7-O-rutinoside and feruloylquinic acid-O-glycoside as minor constituents in Vernonia amygdalina is reported for the first time.

Recent Publications

1. Imafidon C, Akomolafe R, Sanusi A, Ogundipe O, Olukiran O and Ayowole O (2015) Polyphenolrich extract of Vernonia amygdalina (del.) leaves ameliorated cadmium-induced alterations in feeding pattern and urine volume of male Wistar rats. Journal of Intercultural Ethnopharmacology 4(4):284–292.

2. Johnson C E, Lin L, Harnly J M, Oladeinde F O, Kinyua A M, Michelin R and Bronner Y (2011) Identification of the phenolic components of Vernonia amygdalina and Russelia equisetiformis. Journal of Natural Products 4:57-64.

3. Ong K W, Hsu A, Song L, Huang D and Tan B K H (2011) Polyphenols-rich Vernonia amygdalina shows anti-diabetic effects in streptozotocin-induced diabetic rats. Journal of Ethnopharmacology 133(2):598–607.

4. Ola S S, Catia G, Marzia I, Francesco F V, Afolabi A A and Nadia M (2009) HPLC/DAD/MS characterisation and analysis of flavonoids and cynnamoil derivatives in four Nigerian greenleafy vegetables. Food Chemistry 115(4):1568- 1574.

5. Igile G O, Oleszek W, Jurzysta M, Burda S, Fafunso M and Fasanmade A A (1994) Flavonoids from Vernonia amygdalina and their antioxidant activities. [Erratum to document cited in CA121:251243]. Journal of Agricultural and Food Chemistry 42(11):2445–2448.

Biography

Soleya Dagnon has her expertise in evaluation and chromatography profiling of polyphenols in plants. Her analytical and chromatography evaluation model based on deep cognition of chemical and spectral properties of compounds and their chromatographic behavior creates confidence in the information needed for improving the knowledge. She has built this model after many years of experience in chromatography, method evaluation and teaching both in research and education institutions. At the Plovdiv University, she is teaching Modern Chromatographic Methods and Chromatographic Methods in Pharmaceutical Analysis.