Relaxant effects of quercetin methyl ether derivatives in isolated guinea pig trachea and their structure-activity relationships.

Abstract

In the present study, we attempted to compare quercetin methyl ethers and to look for the structure-activity relationships, which may be helpful for synthesizing more active compounds for the treatment of asthma. Four present and two previously studied quercetin methyl ethers concentration-dependently relaxed histamine (30 microM), carbachol (0.2 microM) and KCl (30 mM) induced precontraction. According to their IC25 values to histamine-induced precontraction, the potency order was quercetin 3,3',4,'5,7-pentamethyl ether (QPME), quercetin 3-methyl ether > quercetin, quercetin 3,4',7-trimethyl ether (ayanin) > quercetin 4'-methyl ether (tamarixetin), quercetin 3,3',4',7,-tetramethyl ether (QTME). Therefore, the methylation at 3, at 5, and at both 3 and 7 positions of the A or/and C ring of quercetin nucleus may increase their tracheal relaxant activity. However, the methylation at the 3' and at the 4' position of the B ring of quercetin nucleus may decrease their tracheal relaxant activity.

• Authors: W C Ko, S W Kuo, J R Sheu, C H Lin, S H Tzeng, C M Chen
• Journal: Planta medica (Planta Med) Vol. 65 Issue 3 Pg. 273-5 (Apr 1999) ISSN: 0032-0943 [Print] Germany
• PMID: 10232080 (Publication Type: Letter, Research Support, Non-U.S. Gov't)

Chemical References

• Quercetin

Topics

• Animals
• Guinea Pigs
• In Vitro Techniques
• Male
• Muscle Relaxation (drug effects)
• Quercetin (analogs & derivatives, chemistry, pharmacology)
• Structure-Activity Relationship
• Trachea (drug effects, physiology)