Isolation and characterization of two acaricidal compounds from Calpurnia aurea subsp. aurea (Fabaceae) leaf extract

Abstract

The menace caused by ticks and tick-borne diseases is a major limitation to the livestock industry in Africa. The high costs and non-availability of synthetic, chemical acaricides to resource-limited farmers, resistance of ticks to available acaricides and residue problems in meat and milk consumed by humans further complicate matters. The use of plant extracts as a possible source of new acaricides has received much interest in the last decade. In our endeavour to discover natural acaricidal compounds, tick toxicant bioassays were conducted and the chloroform fraction of Calpurnia aurea ethanol leaf extract had good acaricidal activity. Further purification of the fraction revealed two flavonoids, isolated from C. aurea for the first time. These flavonoids were characterized as apigenin-7-O-β-D-glycoside and isorhoifolin by means of NMR spectroscopic and mass spectrometry analysis. Isorhoifolin was the most potent compound (LC = 0.65 mg/ml), was not cytotoxic and should be further investigated for its potential as an acaricidal agent.

Theobroma cacao L. compounds: Theoretical study and molecular modeling as inhibitors of main SARS-CoV-2 protease

“…In addition to showing antiviral activity, some studies demonstrate its activity associated with anti-inflammatory processes, which is very important in patients with COVID-19 [95] . On the other hand, no antiviral activity of isorhoifolin has been shown, but anti-acaricidal activity has been reported, with an LC 50 = 0.65 mg·ml -1 [96] , and potential inhibition of β-amyloid protein aggregation. These compounds interact with the Glu166 residue, reaching an occupancy greater than 0.6.…”