Guanine deaminase provides evidence of the increased caffeine content during the piling process of pu'erh tea

Pan, Si-an; Sun, Ying; Li, Mengmeng; Deng, Wei‐Wei; Zhang, Zhengzhu

doi:10.1039/c9ra05655f

Cited by 9 publications

(6 citation statements)

References 21 publications

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“…3.1.1.20 ) secreted by microorganisms is responsible for hydrolyzing gallates into GA in dark teas during microbial fermentation. ,, This could explain the abundant GA in CDTs. In another study, caffeine levels was found to increase significantly after the microbial fermentation of PU tea, and guanine deaminase was reported to have an important relation to the mechanism underlying the increased caffeine content . In addition, microbial fermentation also has a significant influence on the amino acid profiles of CDTs .…”

Section: Discussionmentioning

confidence: 95%

Impact of Various Microbial-Fermented Methods on the Chemical Profile of Dark Tea Using a Single Raw Tea Material

Shi

Wang³

et al. 2021

J. Agric. Food Chem.

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In the present study, we produced Pu-erh, Liubao, Qingzhuan, and Fuzhuan teas using a single raw tea material and applied widely targeted metabolomics to study the impact of various microbial-fermented methods on the chemical profile of dark tea. The contents of catechins and free amino acids decreased drastically, whereas the contents of gallic acid and theabrownins increased significantly during microbial fermentation. Pu-erh tea had the highest content of theabrownins (11.82 ± 0.49%). Moreover, MS-based metabolomics analysis revealed that the different types of dark teas were significantly different from their raw material. A total of 85 differential metabolites were screened among 569 metabolites identified referring to self-compiled database. Glycosylated, hydroxylated, methylated, and condensed and oxidated products originating from microbial bioconversion of their corresponding primitive forms were significantly increased in dark teas. These results suggest that various microbial-fermented methods greatly affect the metabolic profile of dark tea, which can provide useful information for dark tea biochemistry research.

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Section: Discussionmentioning

confidence: 95%

Impact of Various Microbial-Fermented Methods on the Chemical Profile of Dark Tea Using a Single Raw Tea Material

Shi

Wang³

et al. 2021

J. Agric. Food Chem.

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“…For determination of xanthine alkaloids, about 0.1 g (fresh weight) powder was extracted with 1.5 ml 80% (v) methanol in water and sonicated for 30 min at 12°C. All samples were mixed up and down every 10 min and centrifuged at 10,000 rpm for 10 min, then the supernatants were filtered through 0.22 µm membranes before UPLC analysis ( Pan et al, 2019 ).…”

Section: Methodsmentioning

confidence: 99%

“…Xanthine alkaloids in the extracts were measured using an ACQUITY UPLC H-Class instrument (Waters, the United States) and separated on a ACQUITY UPLC BEH C18 Column (2.1 × 100 mm, 1.7 μm in particle size and 130 Å in pore size) at a flow rate of 0.3 ml/min at 35°C with 1 μl sample volume, the mobile phase was selected as 0.2% (v) acetic acid in water (A), and methanol (B), and the gradient elution was as follows: B 6% from 0 to 2 min, to 8% at 3.5 min, to 10% at 4.5 min, to 18% at 7.5 min, to 26% at 10.5 min, to 80% at 13.5 min and kept at 80% for 1 min, to 6% at 16 min and kept at 6% for 1 min, the detection wavelength was set to 278 nm ( Li et al, 2017 ; Pan et al, 2019 ). Xanthine alkaloids were identified by using a high resolution quadrupole time-of-flight mass spectrometry (QTOF MS) on the positive-ion mode, the Agilent 1290 UPLC was interfaced with an Agilent 6545 Q-TOF LC/MS system equipped with electrospray ionization source (ESI).…”

Section: Methodsmentioning

confidence: 99%

Metabolite and Transcriptome Profiling on Xanthine Alkaloids-Fed Tea Plant (Camellia sinensis) Shoot Tips and Roots Reveal the Complex Metabolic Network for Caffeine Biosynthesis and Degradation

Deng

Cheng

et al. 2020

Front. Plant Sci.

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While caffeine is one of the most important bioactive metabolites for tea as the most consumed non-alcohol beverage, its biosynthesis and catabolism in tea plants are still not fully understood. Here, we integrated purine alkaloid profiling and transcriptome analysis on shoot tips and roots fed with caffeine, theophylline, or theobromine to gain further understanding of caffeine biosynthesis and degradation. Shoot tips and roots easily took up and accumulated high concentrations of alkaloids, but roots showed much faster caffeine and theophylline degradation rates than shoot tips, which only degraded theophylline significantly but almost did not degrade caffeine. Clearly feedback inhibition on caffeine synthesis or inter-conversion between caffeine, theophylline, and theobromine, and 3-methylxanthine had been observed in alkaloids-fed shoot tips and roots, and these were also evidenced by significant repression of TCS and MXMT genes critical for caffeine biosynthesis. Among these responsively repressed genes, two highly expressed genes TCS-4 and TCS-8 were characterized for their enzyme activity. While we failed to detect TCS-4 activity, TCS-8 displayed N -methyltransferase activities towards multiple substrates, supporting the complex metabolic network in caffeine biosynthesis in tea plants since at least 13 TCS-like N -methyltransferase genes may function redundantly. This study provides new insight into complex metabolic networks of purine alkaloids in tea plants.

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“…It belongs to the family of methylxanthine alkaloid and is a psychoactive stimulant drug which can be usually extracted from plants like coffee, guarana, cacao, yerba mate etc. ( Pan et al, 2019 ). CAF can be used for the pharmaceutical drug preparations as an analgesic adjuvant, treat conditions like physical fatigue, drowsiness ( Mou et al, 2019 ), apnea of prematurity ( Philip et al, 2018 ) and bronchopulmonary dysplasia in premature infants ( Principi et al, 2018 ).…”

Section: Introductionmentioning

confidence: 99%

Molecular Structure, Spectral Investigations, Hydrogen Bonding Interactions and Reactivity-Property Relationship of Caffeine-Citric Acid Cocrystal by Experimental and DFT Approach

Verma

Srivastava

Srivastava³

et al. 2021

Front. Chem.

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The pharmaceutical cocrystal of caffeine-citric acid (CAF-CA, Form II) has been studied to explore the presence of hydrogen bonding interactions and structure-reactivity-property relationship between the two constituents CAF and Citric acid. The cocrystal was prepared by slurry crystallization. Powder X-ray diffraction (PXRD) analysis was done to characterize CAF-CA cocrystal. Also, differential scanning calorimetry (DSC) confirmed the existence of CAF-CA cocrystal. The vibrational spectroscopic (FT-IR and FT-Raman) signatures and quantum chemical approach have been used as a strategy to get insights into structural and spectral features of CAF-CA cocrystal. There was a good correlation among the experimental and theoretical results of dimer of cocrystal, as this model is capable of covering all nearest possible interactions present in the crystal structure of cocrystal. The spectroscopic results confirmed that (O33-H34) mode forms an intramolecular (C25 = O28∙∙∙H34-O33), while (O26-H27) (O39-H40) and (O43-H44) groups form intermolecular hydrogen bonding (O26-H27∙∙∙N24-C22, O39-H40∙∙∙O52 = C51 and O43-H44∙∙∙O86 = C83) in cocrystal due to red shifting and increment in bond length. The quantum theory of atoms in molecules (QTAIM) analysis revealed (O88-H89∙∙∙O41) as strongest intermolecular hydrogen bonding interaction with interaction energy −12.4247 kcal mol−1 in CAF-CA cocrystal. The natural bond orbital analysis of the second-order theory of the Fock matrix highlighted the presence of strong interactions (N∙∙∙H and O∙∙∙H) in cocrystal. The HOMO-LUMO energy gap value shows that the CAF-CA cocrystal is more reactive, less stable and softer than CAF active pharmaceutical ingredients. The electrophilic and nucleophilic reactivities of atomic sites involved in intermolecular hydrogen bond interactions in cocrystal have been demonstrated by mapping electron density isosurfaces over electrostatic potential i.e. plotting molecular electrostatic potential (MESP) map. The molar refractivity value of cocrystal lies within the set range by Lipinski and hence it may be used as orally active form. The results show that the physicochemical properties of CAF-CA cocrystal are enhanced in comparison to CAF (API).

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Guanine deaminase provides evidence of the increased caffeine content during the piling process of pu'erh tea

Abstract: Wet piling is a key process for producing pu'erh tea because various components change under the action of microorganisms.

Cited by 9 publications

References 21 publications

Impact of Various Microbial-Fermented Methods on the Chemical Profile of Dark Tea Using a Single Raw Tea Material

Impact of Various Microbial-Fermented Methods on the Chemical Profile of Dark Tea Using a Single Raw Tea Material

Metabolite and Transcriptome Profiling on Xanthine Alkaloids-Fed Tea Plant (Camellia sinensis) Shoot Tips and Roots Reveal the Complex Metabolic Network for Caffeine Biosynthesis and Degradation

Molecular Structure, Spectral Investigations, Hydrogen Bonding Interactions and Reactivity-Property Relationship of Caffeine-Citric Acid Cocrystal by Experimental and DFT Approach

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