Structure-radical scavenging activity relationships of phenolic compounds from traditional Chinese medicinal plants

TY - JOUR

T1 - Structure-radical scavenging activity relationships of phenolic compounds from traditional Chinese medicinal plants

AU - Cai, Yi Zhong

AU - Mei Sun, Sun

AU - Jie Xing, Xing

AU - Luo, Qiong

AU - Corke, Harold

N1 - Funding Information: We thank Dr. Zhaoqi Zhan (Shimadzu (Asia Pacific) Pte Ltd, Singapore) for technical assistance in LC-MS analysis. This project was supported by a research grant from the University of Hong Kong.

PY - 2006/5/15

Y1 - 2006/5/15

N2 - Traditional Chinese medicinal plants associated with anticancer contain a wide variety of natural phenolic compounds with various structural features and possessing widely differing antioxidant activity. The structure-radical scavenging activity relationships of a large number of representative phenolic compounds (e.g., flavanols, flavonols, chalcones, flavones, flavanones, isoflavones, tannins, stilbenes, curcuminoids, phenolic acids, coumarins, lignans, and quinones) identified in the traditional Chinese medicinal plants were evaluated using the improved ABTS•+ and DPPH methods. Different categories of tested phenolics showed significant mean differences in radical scavenging activity. Tannins demonstrated the strongest activity, while most quinones, isoflavones, and lignans tested showed the weakest activity. This study confirmed that the number and position of hydroxyl groups and the related glycosylation and other substitutions largely determined radical scavenging activity of the tested phenolic compounds. The differences in radical scavenging activity were attributed to structural differences in hydroxylation, glycosylation and methoxylation. The ortho-dihydroxy groups were the most important structural feature of high activity for all tested phenolic compounds. Other structural features played a modified role in enhancing or reducing the activity. Within each class of phenolic compounds, the structure-activity relationship was elucidated and discussed. This study reveals the structure-activity relationships of a large series of representative natural phenolic compounds more systematically and fully than previous work. Structure-radical scavenging activity relationships of some natural phenolics identified in the medicinal plants were evaluated for the first time.

AB - Traditional Chinese medicinal plants associated with anticancer contain a wide variety of natural phenolic compounds with various structural features and possessing widely differing antioxidant activity. The structure-radical scavenging activity relationships of a large number of representative phenolic compounds (e.g., flavanols, flavonols, chalcones, flavones, flavanones, isoflavones, tannins, stilbenes, curcuminoids, phenolic acids, coumarins, lignans, and quinones) identified in the traditional Chinese medicinal plants were evaluated using the improved ABTS•+ and DPPH methods. Different categories of tested phenolics showed significant mean differences in radical scavenging activity. Tannins demonstrated the strongest activity, while most quinones, isoflavones, and lignans tested showed the weakest activity. This study confirmed that the number and position of hydroxyl groups and the related glycosylation and other substitutions largely determined radical scavenging activity of the tested phenolic compounds. The differences in radical scavenging activity were attributed to structural differences in hydroxylation, glycosylation and methoxylation. The ortho-dihydroxy groups were the most important structural feature of high activity for all tested phenolic compounds. Other structural features played a modified role in enhancing or reducing the activity. Within each class of phenolic compounds, the structure-activity relationship was elucidated and discussed. This study reveals the structure-activity relationships of a large series of representative natural phenolic compounds more systematically and fully than previous work. Structure-radical scavenging activity relationships of some natural phenolics identified in the medicinal plants were evaluated for the first time.

KW - Coumarins

KW - Flavonoids

KW - Lignans

KW - Phenolic acids

KW - Phenolic compounds

KW - Quinones

KW - Radical scavenging activity

KW - Stilbenes

KW - Structure-activity relationships

KW - Tannins

KW - Traditional Chinese medicinal plants

UR - http://www.scopus.com/inward/record.url?scp=33646186813&partnerID=8YFLogxK

U2 - 10.1016/j.lfs.2005.11.004

DO - 10.1016/j.lfs.2005.11.004

M3 - 文章

C2 - 16325868

AN - SCOPUS:33646186813

SN - 0024-3205

VL - 78

SP - 2872

EP - 2888

JO - Life Sciences

JF - Life Sciences

IS - 25

ER -