Antioxidant activity of coumarins and flavonols from the resinous exudate of Haplopappus multifolius

• Published in: Phytochemistry (Oxford) 2006-05, Vol.67 (10), p.984-987
• Main Authors: Torres, René, Faini, Francesca, Modak, Brenda, Urbina, Francisco, Labbé, Cecilia, Guerrero, Juan
• Format: Article
• Language: English
• Subjects: antioxidant activity; Antioxidants; Antioxidants - chemistry; Antioxidants - isolation & purification; Antioxidants - pharmacology; Asteraceae; Biological and medical sciences; Chemical constitution; chemical structure; Coumarins; Coumarins - chemistry; Coumarins - isolation & purification; Coumarins - pharmacology; DPPH; Flavonoids; flavonols; Flavonols - chemistry; Flavonols - isolation & purification; Flavonols - pharmacology; Fundamental and applied biological sciences. Psychology; General pharmacology; Haplopappus; Haplopappus - chemistry; Haplopappus multifolius; Medical sciences; Nuclear Magnetic Resonance, Biomolecular; oxidative stress; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; plant exudates; Plant physiology and development; Resinous exudates; resins; Resins, Plant - chemistry; Resins, Plant - pharmacology; secondary metabolites; spectral analysis; stereochemistry
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2006.03.016

Eight coumarins are the main constituents (84% w/w) of resinous exudates produced on stems and leaves of Haplopappus multifolius growing under oxidative stress conditions. Results show that a high concentration of phenolic coumarins and the presence of quercetin and rhamnetin could account for the protection of the plant against oxidative stress. The antioxidant activity of eight coumarins and two flavonols isolated from Haplopappus multifolius was studied with the DPPH radical method. Results show that a high concentration of phenolic coumarins and the presence of quercetin and rhamnetin in the exudates could account for the protection of the plant against oxidative stress. Structures for the coumarins 6-hydroxy-7-[( E, E)-3′,7′-dimethyl-2′,4′,7′-octatrienyloxy] coumarin and 7-[( E)-3′-methyl-4′-hydroxy-2′-butenyloxy] coumarin are proposed on the basis of spectroscopic evidence.