title: Metabolic profiling and predicting the free radical scavenging activity of guava (Psidium guajava L.) leaves according to harvest time by 1H-nuclear magnetic resonance spectroscopy.
abstract: Guava leaves were classified and the free radical scavenging activity (FRSA) evaluated according to different harvest times by using the (1)H-NMR-based metabolomic technique. A principal component analysis (PCA) of (1)H-NMR data from the guava leaves provided clear clusters according to the harvesting time. A partial least squares (PLS) analysis indicated a correlation between the metabolic profile and FRSA. FRSA levels of the guava leaves harvested during May and August were high, and those leaves contained higher amounts of 3-hydroxybutyric acid, acetic acid, glutamic acid, asparagine, citric acid, malonic acid, trans-aconitic acid, ascorbic acid, maleic acid, cis-aconitic acid, epicatechin, protocatechuic acid, and xanthine than the leaves harvested during October and December. Epicatechin and protocatechuic acid among those compounds seem to have enhanced FRSA of the guava leaf samples harvested in May and August. A PLS regression model was established to predict guava leaf FRSA at different harvesting times by using a (1)H-NMR data set. The predictability of the PLS model was then tested by internal and external validation. The results of this study indicate that (1)H-NMR-based metabolomic data could usefully characterize guava leaves according to their time of harvesting.
authors.affiliation: College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea.
authors.forename: So-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Somi K
authors.initials: SK
authors.lastname: Cho
authors.forename: Sun-Hee
authors.initials: SH
authors.lastname: Hyun
authors.forename: Hae-Eun
authors.initials: HE
authors.lastname: Park
authors.forename: Young-Suk
authors.initials: YS
authors.lastname: Kim
authors.forename: Hyung-Kyoon
authors.initials: HK
authors.lastname: Choi
mesh_terms: D001713:Biphenyl Compounds; D002392:Catechin / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology; D005609:Free Radicals / Q000037:antagonists & inhibitors* / Q000378:metabolism; D062385:Hydroxybenzoates / Q000494:pharmacology; D016018:Least-Squares Analysis; D009682:Magnetic Resonance Spectroscopy; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*; D025341:Principal Component Analysis; D031647:Psidium / Q000737:chemistry*; D012621:Seasons; D013997:Time Factors
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D062385:Hydroxybenzoates; D010851:Picrates; D010936:Plant Extracts; C009091:protocatechuic acid; D002392:Catechin; C004931:1,1-diphenyl-2-picrylhydrazyl