Application of Urinary Polyphenol Biomarkers Measured by Liquid Chromatography Tandem Mass Spectrometry to Assess Polyphenol Intake and Their Association with Overweight and Obesity in Free-Living Healthy Subjects

Figure 3

Principal component analysis plot for polyphenol-rich and normal diets with urinary polyphenol biomarkers. Arabic numerals of 1-22 represent caffeic acid, ferulic acid, chlorogenic acid, coumaric acid, cinnamic acid, syringic acid, vanillic acid, protocatechuic acid, quercetin, quercetin 3-glucuronide, kaempferol, naringenin, hesperetin, (3,4)-dihydroxyphenylacetic acid, hydroxyhippuric acid, 3-hydroxybenzoic acid, homovanillic acid, 3-hydroxy-4-methoxycinnamic acid, sinapic acid, hippuric acid, 3-hydroxyphenylacetic acid, and 3-(4-hydroxyphenyl) propionic acid, respectively. The ellipses represent the 80% confidence intervals.