Publications by authors named "Guanhu Bao"

Tea drinking impacts aging and aging-related diseases. However, knowledge of anti-aging molecules other than the major catechins in complex tea extracts remains limited. Here we used Caenorhabditis elegans to analyze the longevity effects of tea extracts and constituents comprehensively.

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Article Synopsis
  • - This study investigates how large-leaf yellow tea polysaccharides (ULYTP-1) can protect against the harmful side effects of the chemotherapy drug 5-fluorouracil (5-Fu), which is commonly used in cancer treatment.
  • - ULYTP-1 activates autophagy and reduces oxidative stress and inflammation triggered by 5-Fu, demonstrating its protective effects in laboratory conditions and in mice with tumors.
  • - The findings suggest that ULYTP-1 not only reduces the toxicity of 5-Fu on immune organs and the liver but also enhances the drug's ability to fight tumors, offering a potential new approach to improve chemotherapy outcomes.
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  • - The study synthesized novel flavonol alkaloids from green tea through thermal reactions of myricetin, quercetin, and kaempferol, identifying them in specific green tea cultivars using advanced chromatography and mass spectrometry techniques.
  • - The structural analysis of these compounds was conducted using 1D and 2D NMR spectroscopies, uncovering their potential therapeutic effects against Alzheimer's disease.
  • - One particular compound showed a strong binding affinity to amyloid β, significantly improving lifespan and neuroprotection in a transgenic worm model, indicating its potential health benefits.
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Cordyceps chanhua on artificial media has been approved as a medicine food homology product. However, the metabolites have not been extensively studied. HPLC-HRMS analysis showed that there were 11 main metabolites in the EtOAc extract including 4 probable unknown compounds.

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Three new cyclic peptides, meristosporins A, B, and C (-), one of which features an unusual amino acid, were isolated from the opportunistic pathogen and identified by 1D, 2D NMR, MS/MS, and Marfey's analysis. The biosynthetic pathway of the hexapeptide meristosporin A () was deduced based on nonribosomal peptide synthetase gene clusters analysis. Compounds and showed cytotoxicity to RAW264.

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Epigallocatechin-3--(4--methyl)gallate (EGCG4″Me) in possesses numerous beneficial biological activities. However, the germplasm rich in EGCG4″Me and the -methyltransferase responsible for EGCG4″Me biosynthesis are poorly understood. Herein, the content of EGCG3″Me and EGCG4″Me in the shoots of 13 cultivars was analyzed to demonstrate that EGCG4″Me is characteristically accumulated in the "GZMe4" cultivar but not in the other 12 cultivars.

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Basidiobolus meristosporus is an opportunistic pathogen of mammals with unique habitats, but its metabolites have not been extensively studied. Through semi-preparative HPLC, nine undescribed cyclic pentapeptides were isolated from mycelia of B. meristosporus RCEF4516.

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Methylation is a common structural modification of catechins in tea, which can improve the bioavailability of catechins. Flavoalkaloids are catechin derivatives with a nitrogen containing five-membered ring at the C-6 or C-8 position. Here we isolated three new methylated flavoalkaloids from Echa 1 green tea (Camellia sinensis cv.

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Cordyceps militaris (C. militaris) has been approved and widely used in healthy food. The present study aimed to improve the flavor of summer Keemun black tea (KBT) using C.

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SARS-CoV-2 M (Mpro) is the critical cysteine protease in coronavirus viral replication. Tea polyphenols are effective M inhibitors. Therefore, we aim to isolate and synthesize more novel tea polyphenols from Zhenghedabai (ZHDB) white tea methanol-water (MW) extracts that might inhibit COVID-19.

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Green tea polyphenols show positive effects on human health and longevity. However, knowledge of the antiaging properties of green tea is limited to the major catechin epigallocatechin gallate (EGCG). The search for new ingredients in tea with strong antiaging activity deserves further study.

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High-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) analysis revealed that there are 20 main components in spores and mycelia extract of Cordyceps fumosorosea strain RCEF 6672 including mannitol (1), uridine (2), adenine (3). N-(2-hydroxyethyl)-adenosine (4). N-(2-hydroxyethylacetate)-adenosine (5), fumosoroseanoside A (6) and B (7), ovalicin-4α-alcohol (8), 1-linoleoyl-sn-glycero-3-phosphocholine (9) and its isomer (10), fumosoroseain A (11) and its isomer (12), 5 non-ribosomal peptides (13 to 17) and 3 fatty acids (18 to 20).

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Current studies have shown that plasma trimethylamine N-oxide (TMAO) level is closely related to the risk of acute myocardial infarction (AMI), that is, the possibility of AMI occurrence is positively correlated with TMAO level. The production of TMAO is mainly due to the transformation of trimethylamine (TMA) through the hepatic flavin-containing monooxygenase. Hence, inhibition of TMA production is essential.

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Vascular endothelial cell injury induced by high glucose (HG) plays an important role in the occurrence and development of diabetic vascular complications. Yellow tea has a protective effect on vascular endothelial cells. However, the molecular mechanisms underlying this effect are unclear.

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Introduction: Widespread use of antibiotics has led to an increase in bacterial multiple drug resistance, thereby searching for natural antimicrobial agents from plants becomes an effective and alternative approach. In the present study, we selected six foodborne bacteria to evaluate the antibacterial activities of 12 medicinal plants ethyl acetate (EA) extracts.

Objective: This study aims to search for natural antibiotic substitutes from plant extracts.

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Flavoalkaloids are a unique class of compounds in tea, most of which have an -ethyl-2-pyrrolidinone moiety substituted at the A ring of a catechin skeleton. 1-Ethyl-5-hydroxy-pyrrolidone, a decomposed product of theanine, was supposed to be the key intermediate to form tea flavoalkaloids. However, we have also detected another possible theanine intermediate, 1-ethyl-5-oxopyrrolidine-2-carboxylic acid, and speculated if there are related conjugated catechins.

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Background And Purpose: Previous studies suggest that major Camellia sinensis (tea) catechins can inhibit 3-chymotrypsin-like cysteine protease (3CLpro), inspiring us to study 3CLpro inhibition of the recently discovered catechins from tea by our group.

Methods: Autodock was used to dock 3CLpro and 16 tea catechins. Further, a 3CLpro activity detection system was used to test their intra and extra cellular 3CLpro inhibitory activity.

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Formation of catechins-human serum albumin (HSA) complex contributes to stably transporting catechins and regulating their bioavailability. Recently, a new class of catechins namely flavoalkaloids have been reported from tea. The unique structural modification with an N-ethyl-2-pyrrolidinone ring at catechins from these flavoalkaloids has raised our interest in their HSA binding affinity.

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Previous study found a high content of kaempferol-3-O-rutinoside (KR) in Lu'an GuaPian tea, however, the rat plasma protein binding and mechanism of KR for cardiovascular protection are unclear. Thus, we studied plasma protein binding using ultrafiltration followed by UPLC, and screened its inhibition against LPS-induced inflammation injury in vitro as well as the underlying mechanism by molecular docking and western blot. KR showed over 74% plasma protein binding ratio.

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Tea, a worldwide popular beverage rich in polyphenols, contributes to the prevention of many diseases and thus is beneficial to human health. Tea is a product through processing the fresh leaves picked from the plant Camellia sinensis (C. sinensis, genus Camellia section Thea).

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Tea is an important beverage source of dietary polyphenols and well known for containing phenolic structure diversity. A series of phenylpropanoid-substituted catechins, flavonols, flavan-3-hexoside, and proanthocyanidin are present in different herbs with various biological activities, inspiring our exploration of phenylpropanoid-substituted ester type of catechins (PSECs) due to the enrichment of galloylated catechins in tea. In this study, we used a guiding-screening-location-isolation integrated route including creating a hypothesized PSEC dataset, MS/MS data acquiring, construction of molecular networks, and traditional column chromatography and preliminarily identified 14 PSECs by MS/MS spectrum.

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Objective: The LC-MS/MS-based non-targeted metabolomics method was used to differentially screen serum and urine metabolites of acute kidney injury (AKI) patients and healthy people, to explore potential biomarkers of AKI and analyze related pathways, and explain the potential mechanism and biological significance of AKI.

Methods: The serum and urine samples from 30 AKI patients and 20 healthy people were selected to conduct a non-targeted metabolomics study by ultra-high-performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). The differential metabolites between the two groups were searched by the human metabolome (HMDB) database ( https://hmdb.

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Flavoalkaloids have been found from tea. However, there is limited information about their content in different teas. Herein, 51 tea samples were screened for flavoalkaloid content.

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Dark teas are prepared by a microbial fermentation process. Flavan-3-ol B-ring fission analogues (FBRFAs) are some of the key bioactive constituents that characterize dark teas. The precursors and the synthetic mechanism involved in the formation of FBRFAs are not known.

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Two new cyclopentapeptides, basidiosins A and B (1 and 2) were isolated from the mycelia extracts of entomophthoralean fungus Basidiobolus meristosporus RCEF 4516. The structures were determined based on spectroscopic methods, and the absolute config urations were assigned by Marfey's method on their acid hydrolyzates. Compounds 1 and 2 were identified as cyclo(L-Thr-L-Leu- L-Ile-D-Tyr-D-Thr) and cyclo(L-Thr-L-Leu-L-Val-D-Val-D-Ser), respectively.

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