Phytochemical Profiling and Isolation of Bioactive Polyphenols From Ipomoea carnea

Abstract

Four solvent fractions were obtained by successive extraction of Ipomoea carnea aerial parts. Five polyphenols were isolated and identified by spectroscopic methods from the ethyl acetate (EA) fraction named tiliroside (2) and from butanol (Bu) fraction named, apigenin-7β-O-glucoside (3), 3,5-di-O-caffeoylquinic acid (4) and two stereoisomers of 3,4-di-O-caffeoylquinic acid (5, 6) in addition to scopoletin (1) from methylene chloride (MC) fraction. GC/MS analysis of petroleum ether (PT) and MC fractions showed thirty-three compounds as well as, thirteen alkaloids were identified by using UPLC-ESI/MS/MS from alkaloid sub fraction (AK-sF) of MC. Insecticidal potentials of different fractions and the pure isolated compounds were evaluated for the first time on Aphis craccivora and Bemisia tabaci. The obtained results indicated that alkaloid sub fraction was the most potent against the two insects. Biochemical investigations of different six enzymes elucidated mode of action of the most potent fraction. Antioxidant activity of I. carnea fractions and pure compounds was performed against DPPH radical. The present study clarified that caffeoylquinic acid (4-6) are mostly responsible for the antioxidant activity of I. carnea Bu fraction while the strong insecticidal activity of MC fraction was due to the ergoline alkaloids found in its AK-sF.