Caffeoylquinic acid

This substance is found in a number of plants including artichoke leaf and celery.

Chemical constituents of fresh celery
Zhongguo Zhong Yao Za Zhi. 2009 Jun; Department of Natural Products Chemistry, Shenyang Pharmaceutical University, Shenyang 110016, China.
To study the chemical constituents of the whole plant of fresh celery (Apium graveolens). METHOD: The constituents were isolated and purified by silica gel, Sephadex LH-20, ODS column chromatography, PTLC, HPLC, and their structures were elucidated on the basis of spectral evidences. RESULT: Twenty compounds were obtained and identified as falcariondiol, (9Z) 1,9-heptadecadiene-4,6-diyne-3,8,11-triol, oplopandiol, bergapten, 5,8-dimethoxy psoralen, isofraxidin, eugenic acid, trans-ferulic acid, trans-cinnamic acid, p-hydroxyphenylethanol ferulate, caffeoylquinic acid, 5-p-trans-coumaroylquinic acid, sedanolide, lunularin, lunularic acid, 2-(3-methoxy-4-hydroxyphenol)-propane-1,3-diol, D-allitol, beta-sitosterol, benzolic acid, succinic acid.

Evaluation of free radical scavenging and antihemolytic activities of quince (Cydonia oblonga) leaf: a comparative study with green tea (Camellia sinensis).
Food Chem Toxicol. 2009 Jan 20. Costa RM, Magalhães AS, Pereira JA, Andrade PB, Valentão P, Carvalho M, Silva BM. CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, R. Carlos da Maia, 296, 4200-150 Porto, Portugal.
This study aimed to determine the phenolic profile and to investigate the antioxidant potential of quince (Cydonia oblonga) leaf, comparing it with green tea (Camellia sinensis). For these purposes, methanolic extracts were prepared and phenolics content of quince leaf was determined by HPLC/UV. The antioxidant properties were assessed by Folin-Ciocalteu reducing capacity assay and by the ability to quench the stable free radical 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and to inhibit the 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of human erythrocytes. 5-O-Caffeoylquinic acid was found to be the major phenolic compound in quince leaf extract. Quince leaf exhibited a significantly higher reducing power than green tea (mean value of 227.8 +/- 34.9 and 112.5 +/- 1.5 g/kg dry leaf, respectively). Quince leaf extracts showed similar DPPH radical scavenging activities (EC(50) mean value of 21.6 +/- 3.5 mug/ml) but significantly higher than those presented by green tea (EC(50) mean value of 12.7 +/- 0.1 mug/ml). Under the oxidative action of AAPH, quince leaf methanolic extract significantly protected the erythrocyte membrane from hemolysis in a similar manner to that found for green tea (IC(50) mean value of 30 and 24 mug/ml, respectively. These results point that quince leaf may have application as preventive or therapeutic agent in diseases in which free radicals are involved.

Caffeoylquinic acid derivatives from leaves of Lonicera japonica
Zhongguo Zhong Yao Za Zhi. 2009 Sep;34(18):2346-8. Tangshan Vocational and Technical College, Tangshan 063000, China
To study the caffeoylquinic acid derivatives from the leaves of Lonicera japonica. The compounds were isolated by column chromatography and identified on the basis of physico-chemical constants and spectral analysis. Five caffeoylquinic acid derivatives were isolated, and their structures were identified as 3,4-di-O-caffeoyl quinic acid methyl ester, 5-O-caffeoyl quinic acid methyl ester, 3,4-di-O-caffeoyl quinic acid, 1,3-di-O-caffeoyl quinic acid and chlorogenic acid.