title: Occurrence of glycosidically conjugated 1-phenylethanol and its hydrolase β-primeverosidase in tea (Camellia sinensis) flowers.
abstract: A previous study found that 1-phenylethanol (1PE) was a major endogenous volatile compound in tea (Camellia sinensis) flowers and can be transformed to glycosically conjugated 1PE (1PE-Gly). However, occurrences of 1PE-Gly in plants remain unknown. In this study, four 1PE-Glys have been isolated from tea flowers. Three of them were determined as (R)-1PE β-d-glucopyranoside ((R)-1PE-Glu), (S)-1PE-Glu, and (S)-1PE β-primeveroside ((S)-1PE-Pri), respectively, on the basis of NMR, MS, LC-MS, and GC-MS evidence. The other one was identified as (R)-1PE-Pri on the basis of LC-MS and GC-MS data. Moreover, these 1PE-Glys were chemically synthesized as the authentic standards to further confirm their occurrences in tea flowers. 1PE-Glu had a higher molar concentration than 1PE-Pri in each floral stage and organ. The ratio of (R) to (S) differed between 1PE-Glu and 1PE-Pri. In addition, a 1PE-Gly hydrolase β-primeverosidase recombinant protein produced in Escherichia coli exhibited high hydrolysis activity toward (R)-1PE-Pri. However, β-primeverosidase transcript level was not highly expressed in the anther part, which accumulated the highest contents of 1PE-Gly and 1PE. This suggests that 1PE-Gly may not be easily hydrolyzed to liberate 1PE in tea flowers. This study provides evidence of occurrences of 1PE-Glys in plants for the first time.
authors: Key Laboratory of Plant Resource Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences , Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors: Ying
authors: Y
authors: Zhou
authors: Fang
authors: F
authors: Dong
authors: Aiko
authors: A
authors: Kunimasa
authors: Yuqian
authors: Y
authors: Zhang
authors: Sihua
authors: S
authors: Cheng
authors: Jiamin
authors: J
authors: Lu
authors: Ling
authors: L
authors: Zhang
authors: Ariaki
authors: A
authors: Murata
authors: Frank
authors: F
authors: Mayer
authors: Peter
authors: P
authors: Fleischmann
authors: Naoharu
authors: N
authors: Watanabe
authors: Ziyin
authors: Z
authors: Yang
mesh_terms: D001592:Benzyl Alcohols / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D028241:Camellia sinensis / Q000737:chemistry* / Q000201:enzymology / Q000254:growth & development; D002681:China; D002851:Chromatography, High Pressure Liquid; D018556:Crops, Agricultural / Q000737:chemistry* / Q000201:enzymology / Q000254:growth & development; D035264:Flowers / Q000737:chemistry* / Q000201:enzymology / Q000254:growth & development; D005503:Food Additives / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D018506:Gene Expression Regulation, Plant; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D006027:Glycosides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006868:Hydrolysis; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009812:Odorants; D010626:Phenylethyl Alcohol / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013379:Substrate Specificity
chemical_list: D001592:Benzyl Alcohols; D005503:Food Additives; D006027:Glycosides; D010940:Plant Proteins; D011994:Recombinant Proteins; C002017:methylphenyl carbinol; D006026:Glycoside Hydrolases; C460087:beta-primeverosidase; D010626:Phenylethyl Alcohol