Association between the neutrophil-to-lymphocyte ratio and in-hospital mortality in patients with chronic kidney disease and coronary artery disease in the intensive care unit.

BACKGROUND: The objective of this study was to investigate the correlation between neutrophil-to-lymphocyte ratios (NLR) and the risk of in-hospital death in patients admitted to the intensive care unit (ICU) with both chronic kidney disease (CKD) and coronary artery disease (CAD). METHODS: Data from the MIMIC-IV database, which includes a vast collection of more than 50,000 ICU admissions occurring between 2008 and 2019, was utilized in the study and eICU-CRD was conducted for external verification. The Boruta algorithm was employed for feature selection. Univariable and multivariable logistic regression analyses and multivariate restricted cubic spline regression were employed to scrutinize the association between NLR and in-hospital mortality. The receiver operating characteristic (ROC) curves were conducted to estimate the predictive ability of NLR. RESULTS: After carefully applying criteria to include and exclude participants, a total of 2254 patients with CKD and CAD were included in the research. The findings showed a median NLR of 7.3 (4.4, 12.1). The outcomes of multivariable logistic regression demonstrated that NLR significantly elevated the risk of in-hospital mortality (OR 2.122, 95% confidence interval [CI] 1.542-2.921, P < 0.001) after accounting for all relevant factors. Further insights from subgroup analyses unveiled that age and Sequential Organ Failure Assessment (SOFA) scores displayed an interactive effect in the correlation between NLR and in-hospital deaths. The NLR combined with traditional cardiovascular risk factors showed relatively great predictive value for in-hospital mortality (AUC 0.750). CONCLUSION: The findings of this research indicate that the NLR can be used as an indicator for predicting the likelihood of death during a patient's stay in the intensive care unit, particularly for individuals with both CAD and CKD. The results indicate that NLR may serve as a valuable tool for assessing and managing risks in this group at high risk. Further investigation is required to authenticate these findings and investigate the mechanisms that underlie the correlation between NLR and mortality in individuals with CAD and CKD.

An allelic series of spontaneous Rorb mutant mice exhibit a gait phenotype, changes in retina morphology and behavior, and gene expression signatures associated with the unfolded protein response.

The Retinoid-related orphan receptor beta (RORß) gene encodes a developmental transcription factor and has 2 predominant isoforms created through alternative first exon usage; one specific to the retina and another present more broadly in the central nervous system, particularly regions involved in sensory processing. RORß belongs to the nuclear receptor family and plays important roles in cell fate specification in the retina and cortical layer formation. In mice, loss of RORß causes disorganized retina layers, postnatal degeneration, and production of immature cone photoreceptors. Hyperflexion or "high-stepping" of rear limbs caused by reduced presynaptic inhibition by Rorb-expressing inhibitory interneurons of the spinal cord is evident in RORß-deficient mice. RORß variants in patients are associated with susceptibility to various neurodevelopmental conditions, primarily generalized epilepsies, but including intellectual disability, bipolar, and autism spectrum disorders. The mechanisms by which RORß variants confer susceptibility to these neurodevelopmental disorders are unknown but may involve aberrant neural circuit formation and hyperexcitability during development. Here we report an allelic series in 5 strains of spontaneous Rorb mutant mice with a high-stepping gait phenotype. We show retinal abnormalities in a subset of these mutants and demonstrate significant differences in various behavioral phenotypes related to cognition. Gene expression analyses in all 5 mutants reveal a shared over-representation of the unfolded protein response and pathways related to endoplasmic reticulum stress, suggesting a possible mechanism of susceptibility relevant to patients.

Sciatic Nerve Block Combined with Flurbiprofen Inhibits Spinal Cord Inflammation and Improves Postoperative Pain in Rats with Plantar Incision.

Background and Purpose: Peripheral nerve block is often used to relieve postoperative pain. But the effect of nerve block on inflammatory response is not fully understood. Spinal cord is the primary center of pain processing. This study is to investigate the effect of single sciatic nerve block on the inflammatory response of the spinal cord in rats with plantar incision and the combined effect with flurbiprofen. Methods: The plantar incision was used to establish a postoperative pain model. Single sciatic nerve block, intravenous flurbiprofen or the combination of both were used for intervention. The sensory and motor functions after nerve block and incision were evaluated. The changes of IL-1ß, IL-6, TNF-α, microglia and astrocytes in the spinal cord were examined by qPCR and immunofluorescence respectively. Results: Sciatic nerve block with 0.5% ropivacaine in rats induced sensory block for 2h and motor block for 1.5h. In the rats with plantar incision, the single sciatic nerve block did not alleviate postoperative pain or inhibit the activation of spinal microglia and astrocytes, but the levels of IL-1ß and IL-6 in spinal cord were decreased when the nerve block wore off. The combined effect of a single sciatic nerve block and intravenous flurbiprofen not only decreased the levels of IL-1ß, IL-6, and TNF-α, but also relieved the pain and alleviated the activation of microglia and astrocytes. Conclusion: The single sciatic nerve block cannot improve postoperative pain or inhibit the activation of spinal cord glial cells, but can reduce the expression of spinal inflammatory factors. Nerve block combined with flurbiprofen can inhibit spinal cord inflammation and improve postoperative pain. This study provides a reference for rational clinical application of nerve block.

The advantages of penehyclidine hydrochloride over atropine in acute organophosphorus pesticide poisoning: A meta-analysis.

Background: Penehyclidine hydrochloride (PHC) has been used for many years as an anticholinergic drug for the treatment of acute organophosphorus pesticide poisoning (AOPP). The purpose of this meta-analysis was to explore whether PHC has advantages over atropine in the use of anticholinergic drugs in AOPP. Methods: We searched Scopus, Embase, Cochrane, PubMed, ProQuest, Ovid, Web of Science, China Science and Technology Journal Database (VIP), Duxiu, Chinese Biomedical literature (CBM), WanFang, and Chinese National Knowledge Infrastructure (CNKI), from inception to March 2022. After all qualified randomized controlled trials (RCTs) were included, we conducted quality evaluation, data extraction, and statistical analysis. Statistics using risk ratios (RR), weighted mean difference (WMD), and standard mean difference (SMD). Results: Our meta-analysis included 20,797 subjects from 240 studies across 242 different hospitals in China. Compared with the atropine group, the PHC group showed decreased mortality rate (RR=0.20, 95% confidence intervals [CI]: 0.16-0.25, P <0.001), hospitalization time (WMD=-3.89, 95% CI: -4.37 to -3.41, P <0.001), overall incidence rate of complications (RR=0.35, 95% CI: 0.28-0.43, P <0.001), overall incidence of adverse reactions (RR=0.19, 95% CI: 0.17-0.22, P <0.001), total symptom disappearance time (SMD=-2.13, 95% CI: -2.35 to -1.90, P <0.001), time for cholinesterase activity to return to normal value 50-60% (SMD=-1.87, 95% CI: -2.03 to -1.70, P <0.001), coma time (WMD=-5.57, 95% CI: -7.20 to -3.95, P <0.001), and mechanical ventilation time (WMD=-2.16, 95% CI: -2.79 to -1.53, P <0.001). Conclusion: PHC has several advantages over atropine as an anticholinergic drug in AOPP.

Novel electrochemical sensing platform basing on di-functional stimuli-responsive imprinted polymers for simultaneous extraction and determination of metronidazole.

A novel magnetic-controlled electrochemical sensor has been fabricated by combined photo-responsive surface molecular imprinted polymers (P-SMIPs) and electrochemical sensor. In particular, the P-SMIPs were obtained by living radical polymerization of photo-responsive functional monomer onto the magnetic Fe3O4 modified multi-walled carbon nanotubes nanocomposites. The magnetic glassy carbon electrode was introduced to make the anchoring and removal of P-SMIPs onto the magnetic-controlled glassy carbon electrode easy to manipulate. Driven by UV/vis light, the platform performs releasing and absorption of metronidazole basing on conformational variations of the photo-responsive monomer at the receptor sites part in the P-SMIPs. This process can be tested by the photo-responsive variations of metronidazole electrochemical signal. As the consequence, extracting of P-SMIPs sensor can be conveniently triggered by the controllable UV light intervention measure, leading to effectively improve in both analytes mass transfer rate to the receiving media and extraction efficiency. The experimental result indicated that the excellent recoveries of metronidazole were varied between 77.9% and 89.9% with RSDs ≤4.87% in the biological samples. Therefore, the P-SMIPs sensor shows satisfactory potential in reusable extractions that can be recycled several times with no significant loss of activity, and this utilization strategy can be extended to other analytes, achieving manifold applications of pharmaceutical and environmental.

Cytotoxicity of Local Anesthetics on Bone, Joint, and Muscle Tissues: A Narrative Review of the Current Literature.

Background: Local anesthetics are commonly used in surgical procedures to control pain in patients. Whilst the cardiotoxicity and neurotoxicity of local anesthetics have received much attention, the cytotoxicity they exert against bone, joint, and muscle tissues has yet to be well recognized. Objective: This review aimed to raise awareness regarding how local anesthetics may cause tissue damage and provide a deeper understanding of the mechanisms of local anesthetic-induced cytotoxicity. We summarized the latest progress on the cytotoxicity of local anesthetics and the underlying mechanisms and discussed potential strategies to reduce it. Findings: We found that the toxic effects of local anesthetics on bone, joint, and muscle tissues were time- and concentration-dependent in vitro. Local anesthetics induced apoptosis, necrosis, and autophagy through specific cellular pathways. Altogether, this review indicates that toxicity of local anesthetics may be avoided by rationally selecting the appropriate anesthetic, limiting the total amount, and determining the lowest effective concentration and duration.

PHB2 Maintains the Contractile Phenotype of VSMCs by Counteracting PKM2 Splicing.

BACKGROUND: Phenotypic transition of vascular smooth muscle cells (VSMCs) accounts for the pathogenesis of a variety of vascular diseases during the early stage. Recent studies indicate the metabolic reprogramming may be involved in VSMC phenotypic transition. However, the definite molecules that link energy metabolism to distinct VSMC phenotype remain elusive. METHODS: A carotid artery injury model was used to study postinjury neointima formation as well as VSMC phenotypic transition in vivo. RNA-seq analysis, cell migration assay, collagen gel contraction assay, wire myography assay, immunoblotting, protein interactome analysis, co-immunoprecipitation, and mammalian 2-hybrid assay were performed to clarify the phenotype and elucidate the molecular mechanisms. RESULTS: We collected cell energy-regulating genes by using Gene Ontology annotation and applied RNA-Seq analysis of transforming growth factor-ß or platelet-derived growth factor BB stimulated VSMCs. Six candidate genes were overlapped from energy metabolism-related genes and genes reciprocally upregulated by transforming growth factor-ß and downregulated by platelet-derived growth factor BB. Among them, prohibitin 2 has been reported to regulate mitochondrial oxidative phosphorylation. Indeed, prohibitin 2-deficient VSMCs lost the contractile phenotype as evidenced by reduced contractile proteins. Consistently, Phb2SMCKO mice were more susceptible to postinjury VSMC proliferation and neointima formation compared with Phb2flox/flox mice. Further protein interactome analysis, co-immunoprecipitation, and mammalian 2-hybrid assay revealed that prohibitin 2, through its C-terminus, directly interacts with hnRNPA1, a key modulator of pyruvate kinase M1/2 (PKM) mRNA splicing that promotes PKM2 expression and glycolysis. Prohibitin 2 deficiency facilitated PKM1/2 mRNA splicing and reversion from PKM1 to PKM2, and enhanced glycolysis in VSMCs. Blocking prohibitin 2-hnRNPA1 interaction resulted in increased PKM2 expression, enhanced glycolysis, repressed contractile marker genes expression in VSMCs, as well as aggravated postinjury neointima formation in vivo. CONCLUSIONS: Prohibitin 2 maintains VSMC contractile phenotype by interacting with hnRNPA1 to counteract hnRNPA1-mediated PKM alternative splicing and glucose metabolic reprogramming.

Recent Advances in Videolaryngoscopy for One-Lung Ventilation in Thoracic Anesthesia: A Narrative Review.

Since their advent, videolaryngoscopes have played an important role in various types of airway management. Lung isolation techniques are often required for thoracic surgery to achieve one-lung ventilation with a double-lumen tube (DLT) or bronchial blocker (BB). In the case of difficult airways, one-lung ventilation is extremely challenging. The purpose of this review is to identify the roles of videolaryngoscopes in thoracic airway management, including normal and difficult airways. Extensive literature related to videolaryngoscopy and one-lung ventilation was analyzed. We summarized videolaryngoscope-guided DLT intubation techniques and discussed the roles of videolaryngoscopy in DLT intubation in normal airways by comparison with direct laryngoscopy. The different types of videolaryngoscopes for DLT intubation are also compared. In addition, we highlighted several strategies to achieve one-lung ventilation in difficult airways using videolaryngoscopes. A non-channeled or channeled videolaryngoscope is suitable for DLT intubation. It can improve glottis exposure and increase the success rate at the first attempt, but it has no advantage in saving intubation time and increases the incidence of DLT mispositioning. Thus, it is not considered as the first choice for patients with anticipated normal airways. Current evidence did not indicate the superiority of any videolaryngoscope to another for DLT intubation. The choice of videolaryngoscope is based on individual experience, preference, and availability. For patients with difficult airways, videolaryngoscope-guided DLT intubation is a primary and effective method. In case of failure, videolaryngoscope-guided single-lumen tube (SLT) intubation can often be achieved or combined with the aid of fibreoptic bronchoscopy. Placement of a DLT over an airway exchange catheter, inserting a BB via an SLT, or capnothorax can be selected for lung isolation.

Oncogenic extrachromosomal DNA functions as mobile enhancers to globally amplify chromosomal transcription.

Extrachromosomal, circular DNA (ecDNA) is emerging as a prevalent yet less characterized oncogenic alteration in cancer genomes. We leverage ChIA-PET and ChIA-Drop chromatin interaction assays to characterize genome-wide ecDNA-mediated chromatin contacts that impact transcriptional programs in cancers. ecDNAs in glioblastoma patient-derived neurosphere and prostate cancer cell cultures are marked by widespread intra-ecDNA and genome-wide chromosomal interactions. ecDNA-chromatin contact foci are characterized by broad and high-level H3K27ac signals converging predominantly on chromosomal genes of increased expression levels. Prostate cancer cells harboring synthetic ecDNA circles composed of characterized enhancers result in the genome-wide activation of chromosomal gene transcription. Deciphering the chromosomal targets of ecDNAs at single-molecule resolution reveals an association with actively expressed oncogenes spatially clustered within ecDNA-directed interaction networks. Our results suggest that ecDNA can function as mobile transcriptional enhancers to promote tumor progression and manifest a potential synthetic aneuploidy mechanism of transcription control in cancer.

A network-based analysis and experimental validation of traditional Chinese medicine Yuanhu Zhitong Formula in treating neuropathic pain.

ETHNOPHARMACOLOGICAL RELEVANCE: The Yuanhu Zhitong Formula (YZF) consists of traditional Chinese herbs Corydalis Rhizoma (Corydalis yanhusuo (Y.H.Chou & Chun C.Hsu) W.T.Wang ex Z.Y.Su & C.Y.Wu; Chinese name, Yanhusuo) and Angelicae Dahuricae Radix (Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav.; Chinese name, Baizhi), which is usually administrated for painful conditions. It is well acknowledged that YZF has pharmacological effects on pain relief; nevertheless, limited data are available on its mechanism. AIM OF THE STUDY: This study aimed to explore the potential mechanism underlying YZF on nociception of rats. Also, the comprehensive mechanism of YZF was preliminarily determined based on network pharmacology on neuropathic pain. MATERIALS AND METHODS: A spared nerve injury (SNI) model was established to reveal the effects of YZF administration on nociceptive behavior in rats. Von-Frey tests were used to evaluate the paw withdrawal mechanical thresholds in rats administrated with YZF or vehicle. The "drug-ingredients" and "disease-drug-target" networks were established with a network pharmacology approach. The analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) profiles were performed based on the common targets between the herbs and neuropathic pain. Hub genes, identified with CytoHubba, were validated by Western blotting analysis. RESULTS: SNI rats developed significant nociceptive behavior as soon as 3 days after nerve injury, which was reversed by consecutive treatment with 300 mg/kg YZF for 7 days. Besides, 50 potential bioactive components in YZF with 1074 targets were identified. Then, 217 putative common genes related to YZF and neuropathic pain were identified for further study. After established a protein-protein interaction network, 12 subnetworks with CytoHubba and 10 predictive hub genes were obtained based on the maximal clique centrality model. Western blotting analysis indicated that SNI rats exhibited increased APP (Amyloid-beta precursor protein), SRC (Proto-oncogene tyrosine-protein kinase Src), and phosphorylation of JNK1 (Mitogen-activated protein kinase 8, JNK) and ERK1/2 (Mitogen-activated protein kinase 3/1). Obviously, continuous administration of YZF robustly reversed such changes. CONCLUSIONS: This study revealed that YZF modulates the nociceptive behavior in SNI rats. Moreover, the drug may be useful in the treatment of neuropathic pain through multi-components, multi-targets, and multi-pathways. Nevertheless, more attention should be paid to discriminating the potential ingredients in YZF contributing to its analgesic effects in the treatment of neuropathic pain.

ETCO2 waveforms-assisted awake nasal fibreoptic intubation.

Awake fibreoptic intubation has always been considered the gold standard for expected difficult airway management. However, the use of fibreoptic intubation was limited because it is time-consuming, requires skillful operators and easily affected by blood or secretions in the oral or nasopharynx. We reported a modified technique of awake fibreoptic nasal intubation with the aid of End-tidal carbon dioxide (ETCO2) monitoring, aiming to improve the efficiency and safety of awake fibreoptic intubation.

Particle size distributions and health risks of polychlorinated dibenzo-p-dioxin/furans, polychlorinated biphenyls, and polychlorinated naphthalenes in atmospheric particles around two secondary copper smelters in Shandong Province, China.

Sixteen samples of atmospheric particles in four size fractions (diameter: > 10 µm, 5-10 µm, 2.5-5 µm, and <2.5 µm) were collected around two secondary copper smelters in Shandong Province, China. The levels, particle size distributions, and potential health risks of polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs) in these samples were analyzed. The concentration ranges for the PCDD/Fs, dl-PCBs, and PCNs were 3.13-5.77 pg m-3, 0.43-0.56 pg m-3, and 4.76-9.89 pg m-3, respectively. All of the compounds accumulated strongly in the particles with diameters of <2.5 µm. The congener profiles of PCDD/Fs in particles of various sizes were similar, and were consistent with those in stack gases from local secondary copper smelters. However, the congener profiles of dl-PCBs and PCNs in the particles with diameters of <2.5 µm differed from those for the other particle size fractions. The proportion of highly chlorinated homologs in particles with diameters of <2.5 µm was much higher than that of particles with diameters of >2.5 µm. The results of a risk assessment indicated that the contribution of PCDD/Fs to the total carcinogenic risk (PCDD/Fs + dl-PCBs + PCNs) was >95%. For the PCDD/Fs, dl-PCBs, and PCNs, 78%, 71%, and 86% of the carcinogenic risk was associated with the <2.5 µm fraction, respectively. This study improves our understanding of the particle size distributions and human health risks of exposure to PCDD/Fs, dl-PCBs, and PCNs in the atmosphere around secondary copper smelters.

The roles of the gut microbiota-miRNA interaction in the host pathophysiology.

The gut microbiota regulates the biological processes of organisms acting like 'another' genome, affecting the health and disease of the host. MicroRNAs, as important physiological regulators, have been found to be involved in health and disease. Recently, the gut microbiota has been reported to affect host health by regulating host miRNAs. For example, Fusobacterium nucleatum could aggravate chemoresistance of colorectal cancer by decreasing the expression of miR-18a* and miR-4802. What's more, miRNAs can shape the gut microbiota composition, ultimately affecting the host's physiology and disease. miR-515-5p and miR-1226-5p could promote the growth of Fusobacterium nucleatum (Fn) and Escherichia coli (E.coli), which have been reported to drive colorectal cancer. Here, we will review current findings of the interactions between the gut microbiota and microRNAs and discuss how the gut microbiota-microRNA interactions affect host pathophysiology including intestinal, neurological, cardiovascular, and immune health and diseases.

Chromatin interaction analyses elucidate the roles of PRC2-bound silencers in mouse development.

Lineage-specific gene expression is modulated by a balance between transcriptional activation and repression during animal development. Knowledge about enhancer-centered transcriptional activation has advanced considerably, but silencers and their roles in normal development remain poorly understood. Here, we performed chromatin interaction analyses of Polycomb repressive complex 2 (PRC2), a key inducer of transcriptional gene silencing, to uncover silencers, their molecular identity and associated chromatin connectivity. Systematic analysis of cis-regulatory silencer elements reveals their chromatin features and gene-targeting specificity. Deletion of certain PRC2-bound silencers in mice results in transcriptional derepression of their interacting genes and pleiotropic developmental phenotypes, including embryonic lethality. While some PRC2-bound elements function as silencers in pluripotent cells, they can transition into active tissue-specific enhancers during development, highlighting their regulatory versatility. Our study characterizes the molecular profile of silencers and their associated chromatin architectures, and suggests the possibility of targeted reactivation of epigenetically silenced genes.

Longitudinal molecular trajectories of diffuse glioma in adults.

The evolutionary processes that drive universal therapeutic resistance in adult patients with diffuse glioma remain unclear1,2. Here we analysed temporally separated DNA-sequencing data and matched clinical annotation from 222 adult patients with glioma. By analysing mutations and copy numbers across the three major subtypes of diffuse glioma, we found that driver genes detected at the initial stage of disease were retained at recurrence, whereas there was little evidence of recurrence-specific gene alterations. Treatment with alkylating agents resulted in a hypermutator phenotype at different rates across the glioma subtypes, and hypermutation was not associated with differences in overall survival. Acquired aneuploidy was frequently detected in recurrent gliomas and was characterized by IDH mutation but without co-deletion of chromosome arms 1p/19q, and further converged with acquired alterations in the cell cycle and poor outcomes. The clonal architecture of each tumour remained similar over time, but the presence of subclonal selection was associated with decreased survival. Finally, there were no differences in the levels of immunoediting between initial and recurrent gliomas. Collectively, our results suggest that the strongest selective pressures occur during early glioma development and that current therapies shape this evolution in a largely stochastic manner.

Polychlorinated naphthalenes in human serum samples from an industrial city in Eastern China: Levels, sources, and sex differences.

Polychlorinated naphthalenes (PCNs) in the environment in China have been studied extensively. However, there have been no reports on PCNs in human serum samples from China. In this context, we collected 480 serum samples from an industrial city in Eastern China. The concentration range for the sum of the mono-to octa-CNs was 14300-50700 pg/g lipid. The most predominant congener was CN-5/7, which accounted for 21.6%-51.1% of the total PCN concentration. Further analysis indicated that residues of PCN industrial technical products in the local environment appear to be the main source of CN-5/7 in the serum samples. On the other hand, the sum of the tetra-to octa-CNs concentration was obviously higher in males (1390 ±â€¯929 pg/g lipid) than in females (267 ±â€¯25 pg/g lipid). Moreover, the concentrations of combustion-related PCNs in the male 20-24, 25-29 and 30-34 years groups were obviously higher than those in the female samples. Therefore, industrial thermal processes are important sources of PCNs in male serum in addition to PCN products. The toxic equivalent (TEQ) concentrations of PCNs in the pooled serum samples ranged from 0.12 to 0.40 pg/g lipid. CN-10 and CN-66/67 were the dominant TEQ congeners in male serum, and CN-10, CN-1, and CN-2 were the main TEQ congeners in female serum.

Back propagation neutral network based signal acquisition for Brillouin distributed optical fiber sensors.

This manuscript proposes a method based on back propagation (BP) neural network and the spectral subtraction method to quickly obtain sensing information in Brillouin fiber optics sensors. BP neural network's characteristics which can realize any complex nonlinear mapping help to determine the frequency shift section(s) information. The training function, transfer function and number of hidden layer nodes of BP neural network are determined with experimental data. The experimental results show that comparing with traditional Lorentz fitting algorithm and edge detection with Sobel operator, the BP neural network is about 1/12 in terms of time complexity with the Lorentz algorithm, about 1/9 with the edge detection based on Sobel operator; while the respective accuracy on determine the frequency shifted section(s) has improved by 79.4% and 27.9%.

Insights into Tissue-specific Specialized Metabolism in Tieguanyin Tea Cultivar by Untargeted Metabolomics.

Tea plants produce extremely diverse and abundant specialized metabolites, the types and levels of which are developmentally and environmentally regulated. However, little is known about how developmental cues affect the synthesis of many of these molecules. In this study, we conducted a comparative profiling of specialized metabolites from six different tissues in a premium oolong tea cultivar, Tieguanyin, which is gaining worldwide popularity due to its uniquely rich flavors and health benefits. UPLC-QTOF MS combined with multivariate analyses tentatively identified 68 metabolites belonging to 11 metabolite classes, which exhibited sharp variations among tissues. Several metabolite classes, such as flavonoids, alkaloids, and hydroxycinnamic acid amides were detected predominantly in certain plant tissues. In particular, tricoumaroyl spermidine and dicoumaroyl putrescine were discovered as unique tea flower metabolites. This study offers novel insights into tissue-specific specialized metabolism in Tieguanyin, which provides a good reference point to explore gene-metabolite relationships in this cultivar.

Metabolite Profiling of 14 Wuyi Rock Tea Cultivars Using UPLC-QTOF MS and UPLC-QqQ MS Combined with Chemometrics.

Wuyi Rock tea, well-recognized for rich flavor and long-lasting fragrance, is a premium subcategory of oolong tea mainly produced in Wuyi Mountain and nearby regions of China. The quality of tea is mainly determined by the chemical constituents in the tea leaves. However, this remains underexplored for Wuyi Rock tea cultivars. In this study, we investigated the leaf metabolite profiles of 14 major Wuyi Rock tea cultivars grown in the same producing region using UPLC-QTOF MS and UPLC-QqQ MS with data processing via principal component analysis and cluster analysis. Relative quantitation of 49 major metabolites including flavan-3-ols, proanthocyanidins, flavonol glycosides, flavone glycosides, flavonone glycosides, phenolic acid derivatives, hydrolysable tannins, alkaloids and amino acids revealed clear variations between tea cultivars. In particular, catechins, kaempferol and quercetin derivatives were key metabolites responsible for cultivar discrimination. Information on the varietal differences in the levels of bioactive/functional metabolites, such as methylated catechins, flavonol glycosides and theanine, offers valuable insights to further explore the nutritional values and sensory qualities of Wuyi Rock tea. It also provides potential markers for tea plant fingerprinting and cultivar identification.

[Isolation and purification of seven catechin compounds from fresh tea leaves by semi-preparative liquid chromatography].

An effective and simple method was established to simultaneously purify seven tea catechins (gallocatechin (GC), epigallocatechin (EGC), catechin (C), epigallocatechin-3-O-gallate (EGCG), epicatechin (EC), epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3"Me) and epicatechin-3-O-gallate (ECG)) from fresh tea leaves by semi-preparative high performance liquid chromatography (HPLC). Fresh leaves of Tieguanyin tea were successively extracted with methanol and chloroform. Then crude catechins were precipitated from the aqueous fraction of chloroform extraction by adding lead subacetate. Crude catechins were used for the isolation of the seven target catechin compounds by semi-preparative HPLC. Methanol-water and acetonitrile-water were sequentially used as mobile phases. After two rounds of semi-preparative HPLC, all target compounds were achieved with high purities (>90%). The proposed method was tested on two additional tea cultivars and showed similar results. This method demonstrated a simple and efficient strategy based on solvent extraction, ion precipitation and semi-preparative HPLC for the preparation of multiple catechins from tea leaves.