Effect of a Commercial Extract of Green Tea and a Pure Catechin on Two Veillonella strains

The catechin Epigallocatechin-3-O-Gallate (EGCG) which is found in of Green Tea extracts (GTE), displays a variety of microbicidal properties. It is largely believed that EGCG inhibits the growth of cariogenic and periodontopathic bacteria. Objective: In this paper we compared the inhibitory activity of EGCG and a commercial GTE on the growth of Veillonella parvula. Chlorhexidine was used as positive control. Methodology: V. parvula ATCC 10790 and a clinical isolate obtained from a periodontal disease patient were cultured in the presence of EGCG or a commercial GTE, and the measurements of bacterial growth inhibition were compared to the values obtained with 0.12 and 0.2% chlorhexidine. Results: Chlorhexidine inhibited bacterial growth, however in contrast to a previous report, neither EGCG nor the GTE showed any effect on bacterial growth. Conclusions: The data show and confirm that chlorhexidine is a growth inhibitor of V. parvula while EGCG and GTE do not display such effect.

Difference Analysis on Contents of Gallic Acid and Catechins of Tea Resources from Yunnan Province

[Objective] This study aimed to analyze the difference in the contents of gallic acid and catechins of tea resources from Yunnan Province. [Method] By using high performance liquid chromatography （HPLC）, the contents of gallic acid （GA）, catechins （C）, epicatechin （EC）, epigallocatechin （EGC）, epicatechin gallate （ECG） and epigallocatechin gallate （EGCG） of 121 tea germplasms from the China National Germplasm Tea Repositories （CNGTR） at the Tea Research Institute of Yunnan Academy of Agricultural Sciences （TRIYAAS） were measured. [Result] The content of GA ranged from 0.210% to 1.902%, with an average of 0.834%, explaining rela- tively low GA content among tea germplasms. The content of C ranged from 0.069% to 8.865%, with an average of 1.916%. The content of EC ranged from 0.126% to 2.865%, with an average of 1.112%. The content of EGC ranged from 0.00% to 3.709%, with an average of 0.954%. The content of ECG ranged from 0.739% to 8.957%, with an average of 4.063%. The content of EGCG ranged from 0.819% to 11.77%, with an average of 5.939%. The content of total C ranged from 6.354% to 22.654%, with an average of 14.042%. [Conclusion] There was relatively big difference of catechin contents among different tea resources, indicating that there was plentiful biodiversity of Yunnan tea germplasms. At the same time, three tea germplasms with high epigallocatechin gallate content （≥10%） was selected preliminarily, which would provide important materials for breeding tea cultivars with high EGCG content in the future.

Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

Objective:To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone.Methods:Green tea GMB-4 clones were extracted with distilled water at 90C.Samples were eluted into the column with 10%ethanol.Subsequently,the column was eluted with95%ethanol and evaporated separately.Green tea extract was identified by thin layer chromatography.Catechins were separated by the stationary phase in column chromatography using polyamide with 10%ethanol eluent and 95%ethanol.The results of isolations were analyzed by high performance liquid chromatographic(HPLC)and LCMS/MS.Analysis of catechins by HPLC was done by external standard.Results:Fraction from 10%ethanol showed that four major peaks at retention time of1.663,2.367,2.950 and 4.890,indicated the presence of four catechins components including catechin,epicatechins,gallocatechin and epigallocatechin.Whereas,fraction from 95%ethanol showed two main peaks at retention time of 5.167 and 9.82,which indicated the presence of epigallocatechin gallate(EGCG)and epicatechin gallate(ECG).EGCG(m/z 459),epigallocatechin(m/z 307),ECG(m/z 443),and epicatechin(m/z 291)were isolated and separated successfully using HPLC and LC-MS/MS.Conclusions:The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG.Four major catechins were separated and identified by LC-MS/MS,such as EGCG,epigallocatechin,ECG and epicatechin.The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

Determination of Residual Catechins, Polyphenolic Contents and Antioxidant Activities of Developed Theaflavin-3,3’-Digallate Rich Black Teas

This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made teas were processed from eleven selected cultivars. A comparative study was carried out between the processed teas and those from commercially grown Kenyan cultivars in relation to the above chemical parameters. A correlation matrix analysis was also conducted to find out whether a relationship existed between the antioxidant activities and the said chemical parameters. The total residual catechins were found to range between 3.10% and 8.08%. The total polyphenol levels varied between 19.00% and 28.90%, while the antioxidant activities of the teas ranged from 82.70% to 91.70%. There was a significant p < 0.001 correlation between the antioxidant activity and total polyphenols (r = 0.8948). There was also a high correlation p < 0.001 between the antioxidant activity and total catechins (r = 0.8878). Out of the four catechin fractions, the antioxidant activity correlated most with EGCG (r = 0.8774). The total polyphenolic contents and antioxidant activities for most of the cultivars were comparable to those of the green tea reference standard. From the figures obtained, it can be concluded that the most of the newly developed black teas of the selected cultivars have higher quality and enhanced antioxidant activities and that they can be recommended for commercial production.

Green tea catechins inhibit microglial activation which prevents the development of neurological disorders

The over-activated microglial cells induce neuroinflammation which has the main role in neurological disorders.The over-activated microglia can disturb neuronal function by releasing inflammatory mediators leading to neuronal dysfunctions and death.Thus,inhibition of over-activated microglia may be an effective therapeutic approach for modulating neuroinflammation.Experimental studies have indicated anti-neuroinflammatory effects of flavonoids such as green tea catechins.The current research was aimed to review the effect of green tea catechins in inhibiting microglial cells,inflammatory cascades,and subsequent neurological diseases.

Interaction of catechins with aluminum in vitro

Tea is one of the most popular beverages, consumed by over two thirds of the world’s population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminum’s known adverse effect on human health. Investigation of the interactions of catechins with Al3+ showed that during the interaction of catechins with Al3+, the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322 nm; EC and C’s at 278 nm changed little. The ratio of Al3+ to EGCG was 1:1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the Al-EGCG complex was 1:1. Interestingly, while the ratio reached to over 2, after the complex of Al-EGCG started polymerization, the ratio in the polymer was 2:1. In pH 6.2 buffer solution, the complex behavior of C with Al3+ was the same as that of EGCG, with a little difference for EC. When the ratio of Al3+ to EC was <1, the complex in ratio was 1:2, but, the complex polymerized when the ratio of Al3+ to EC was >1. It was found that the ratio of Al3+ to EC in the polymer was 1:1. Polymerization of Al-catechin complexes might reduce aluminum absorption in the intestine. Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols on Kow in buffer solution. Results showed that Kow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminum Kow value in acetic buffer, indicating that these compounds may reduce aluminum absorption during tea intake.

Feasibility Study of the Synthesis of Isocyanate-Free Polyurethanes from Catechin

With the current trend of increasing efforts to develop non-isocyanate-based polyurethanes(NIPUs),this study aimed to check the feasibility of the development of a method using cyclic carbonate modified catechin and amine to synthesis non-isocyanate urethane with the objective to further extend these results to polyurethane synthesis.The methods used in this study consist of four steps:glycidilation of catechin,hydrolysis of epoxide,cyclic carbonate synthesis,and carbamate synthesis through condensation of butylamine.The resulting products were analyzed using FTIR(Fourier transform infrared)spectroscopy and NMR(nuclear magnetic resonance)spectroscopy.The results showed that carbamate could be successfully obtained through this four-steps synthesis,opening the possibility to further developments for the synthesis of polyurethanes starting from catechin and condensed tannins.

Identification of miRNAs and target genes regulating catechin biosynthesis in tea (Camellia sinensis)

Micro RNAs（miRNAs） are endogenous non-protein-coding small RNAs that play crucial and versatile regulatory roles in plants. Using a computational identification method, we identified 55 conserved miRNAs in tea（Camellia sinensis） by aligning miRNA sequences of different plant species with the transcriptome library of tea strain 1005. We then used quantitative real-time PCR（qRT-PCR） to analyze the expression of 31 identified miRNAs in tea leaves of different ages, thereby verifying the existence of these miRNAs and confirming the reliability of the computational identification method. We predicted which miRNAs were involved in catechin synthesis using ps RNAtarget Software based on conserved miRNAs and catechin synthesis pathway-related genes. Then, we used RNA ligase-mediated rapid amplification of c DNA ends（RLM-RACE） to obtain seven miRNAs cleaving eight catechin synthesis pathway-related genes including chalcone synthase（CHS）, chalcone isomerase（CHI）, dihydroflavonol 4-reductase（DFR）, anthocyanidin reductase（ANR）, leucoanthocyanidin reductase（LAR）, and flavanone 3-hydroxylase（F3H）. An expression analysis of miRNAs and target genes revealed that miR529d and miR156 g-3 p were negatively correlated with their targets CHI and F3H, respectively. The expression of other miRNAs was not significantly related to their target genes in the catechin synthesis pathway. The RLM-RACE results suggest that catechin synthesis is regulated by miRNAs that can cleave genes involved in catechin synthesis.

Simultaneous Determination of Catechins and Caffeine in Green Tea-Based Beverages and Foods for Specified Health Uses

Catechins in green tea have various useful features including antioxidant activity and preventive effects on metabolic syndrome. Various beverages that are enriched with tea catechins are marketed as Foods for Specified Health Uses (FOSHU) in Japan. However, recent reports have indicated that excessive consumption of green tea extracts as a dietary supplement are associated with adverse health effects such as liver disorders. Various catechins and caffeine are constituents of FOSHU tea-based beverages. The amount of catechins in FOSHU products is displayed on labels as total catechin content, but the content of individual catechins are not provided. Although health hazards of FOSHU products have rarely been reported, precise information about the content and types of catechins in FOSHU products is needed to ensure safety. We used high-performance liquid chromatography with a photodiode array (HPLC/PDA) to simultaneously identify and quantify catechins and caffeine in green tea-based popular beverages and FOSHU beverages. This technique allowed simultaneous quantitation of five types of catechins and caffeine in green tea without complicated sample preparation. Epigallocatechin gallate (EGCG) and epigallocatechin EGC were the main catechins in various FOSHU beverages and the concentrations of almost all catechins were higher in FOSHU, than in popular green tea-based beverages. The concentrations of EGCG in green tea-based popular beverages and in FOSHU beverages were 5.4 - 7.3 and 10.2 - 41.9 mg/100mL, respectively, with the highest concentration being in a product named Healthya (approximately 147 mg/bottle). The simultaneous determination of compounds such as catechins and caffeine in FOSHU beverages can help to estimate beneficial and adverse effects to prevent deleterious effects on health and the excessive consumption of FOSHU beverages containing high concentrations of tea catechins should be avoided.

Physicochemical properties and antibacterial mechanism of theabrownins prepared from different catechins catalyzed by polyphenol oxidase and peroxidase

Theabrownins(TBs)are the characteristic functional and quality components of dark teas such as Pu’er tea and Chin-brick tea.TBs are a class of water-soluble brown polymers with multi-molecular weight distribution produced by the oxidative polymerisation of tea polyphenols during the fermentation process of dark tea,both enzymatically and non-enzymatically.TBs have been extracted and purified from dark tea all the time,but the obtained TBs contain heterogeneous components such as polysaccharides and caffeine in the bound state,which are difficult to remove.The isolation and purification process was tedious and required the use of organic solvents,which made it difficult to industrialise TBs.In this study,epigallocatechin(EGC),epigallocatechin gallate(EGCG),epigallocatechin gallate(ECG),EGC/EGCG(mass ratio 1:1),EGCG/ECG(mass ratio 1:1),EGC/ECG(mass ratio 1:1)and EGC/EGCG/ECG(mass ratio 1:1:1)as substrates and catalyzed by polyphenol oxidase(PPO)and peroxidase(POD)in turn to produce TBs,named TBs-dE-1,TBs-dE-2,TBs-dE-3,TBs-dE-4,TBs-dE-5,TBs-dE-6 and TBs-dE-7.The physicochemical properties and the antibacterial activity and mechanism of TBs-dE-1–7 were investigated.Sensory and colour difference measurements showed that all seven tea browning samples showed varying degrees of brownish hue.Zeta potential in aqueous solutions at pH 3.0–9.0 indicated that TBs-dE-1–7 was negatively charged and the potential increased with increasing pH.The characteristic absorption peaks of TBs-dE-1–7 were observed at 208 and 274 nm by UV-visible(UV-vis)scanning spectroscopy.Fourier transform infrared(FT-IR)spectra indicated that they were phenolic compounds.TBs-dE-1–7 showed significant inhibition of Escherichia coli DH5α(E.coli DH5α).TBs-dE-3 showed the strongest inhibitory effect with minimum inhibitory concentration(MIC)of 1.25 mg mL–1 and MBC of 10 mg mL–1,followed by TBs-dE-5 and TBs-dE-6.These three TBs-dEs were selected to further investigate their inhibition mechanism.The TBs-dE was found to damage the extracellular membrane of E.coli DH5α,causing leakage of contents,and increase intracellular reactive oxygen content,resulting in abnormal cell metabolism due to oxidative stress.The results of the study provide a theoretical basis for the industrial preparation and product development of TBs.

Metabolic profile analysis based on GC-TOF/MS and HPLC reveals the negative correlation between catechins and fatty acids in the cottonseed of Gossypium hirsutum

Background: The diversified and high value-added utilization of cotton by products can promote the sustainable development of modern agriculture. Di erences in potential nutrients among varieties can be explained by variations in the composition and abundance of fatty acids, polyphenols, carbohydrates, amino acids, and organic acids. Therefore, the analysis of metabolite species and relationships in cottonseed is meaningful for the development of cotton byproducts.Results: In this study, the metabolomes of three representative cotton cultivars of di erent species were compared using untargeted GC-TOF/MS analysis. A total of 263 metabolites were identified from 705 peaks, and their levels were compared across cultivars. Principal component analysis and OPLS-DA clearly distinguish these samples based on metabolites. There were significant di erences in the contents of amino acids, carbohydrates, organic acids, flavonoids, and lipids in G. hirsutum TM-1 compared with G. arboreum Shixiya1 and G. barbadense Hai7124. Notably, the bioactive nutrient compound catechin obtained from the di erential metabolites significantly accumulated in TM-1. Furthermore, a comprehensive analysis using catechin and oil-related traits was conducted in core collections of Gossypium hirsutum. The results revealed the reliability of the GC-TOF/MS analysis, as well as that catechin content has a negative association with myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, and total fatty acids.Conclusion: These findings suggest that untargeted GC-TOF/MS analysis could provide a new method for investigating the underlying plant biochemistry of nutrient variation in cottonseed, and that catechin content has a negative association with oil-related traits in cottonseed. This study may pave the way to exploit the value of cotton byproducts.

The effects of circadian rhythm on catechin accumulation in tea leaves

As the major bitter-and astringent-tasting components in tea leaves,catechins play an essential role in determining flavor characteristics and health benefits of tea products.This study analyzed the circadian rhythm effects on the accumulation pattern of catechins in tender leaves of three tea cultivars,'Huangkui'(HK),'Longjing43'(LJ43)and'Fuding Dabaicha'(FD).There were two major factors involved in the catechin regulation in tea plants:genetic background of the cultivar-specific regulation,and temporal effects of the circadian rhythm.Etiolated leaves of'HK'contained lower levels of catechins than'LJ43'and'FD'.The composition of EGCG in total catechins was significantly higher in'LJ43'leaves(65%)when compared with that in'HK'and'FD'(45%).The accumulation of individual catechins increased during the daytime but decreased overnight,especially over the time period of 22:00−02:00.The correlation analysis between catechins and environmental factors indicated catechin accumulation in tea leaves potentially resulted from a combined regulation of light and temperature.These findings provide new insights into our understanding of circadian rhythm regulation on flavor-important secondary metabolites in tea leaves.

Determination and pharmacokinetic study of catechin in rat plasma by HPLC

A high performance liquid chromatographic method was developed and validated for the quantitative determination of catechin in rat plasma and its pharmacokinetic study after intragastric administration of Catechu and Xiongdanjiangre Wan into SD rats. Plasma samples were prepared by protein precipitation using methanol-5% aqueous zinc sulfate （70：30, v/v） as precipitant. Chromatographic separation was achieved on Hypersil Cl8 column （250 mm~ 4.6 mm, 10 pm） with acetonitrile-water-triethylamine （6：94：0.3, v/v/v, pH 4.0＋0.1, adjusted with phos- phoric acid） as mobile phase, followed by a UV detection at 207 nm. Good linearity was obtained over the range of 0.143-7.15 mg/L of catechin, with correlation coefficient of 0.9992. The method was simple, sensitive, accurate and reproducible and＇ has been successfully applied to the pharmacokinetic study of catechin in rat plasma.

Investigation of the Interaction Between Sodium (meta) Arsenite and Catechin via ESI Tandem Mass Spectrometry

Catechin,one of the main components of green tea,is considered to have the remedy effect of arsenic poison,although the chemical mechanism is not well known.In this study,sodium（meta）selenite,which is used as herbicide and insecticide as well as rodenticide,was simply mixed with catechin in the CH3OH/H2O（volume ratio 50∶50）solution to investigate the interaction between toxic inorganic arsenic compound and catechin via ESI tandem mass spectrometry.The interaction products of mono-methylated arsenic with catechin in the presence of methanol were identified in the negative mode.Collission induced dissociation（CID）mass spectrometric measurements indicate that monomethylated arsenic was ＂alkylated＂ strongly by conjugation at the sites of C2＇ and C5＇ in the phenyl ring B of the catechin.The interaction mechanism between sodium（meta）arsenite and catechin was proposed.The results provide useful information to understand the chemical pathway of the detoxification of the arsenic toxicity by catechin.

Study on the Retention Rate of Green Tea Catechins Components and Tea Polyphenol by Different Processing Technology

The aim of this research was to explore the effect of fixation,rolling,and drying processing technology on the retention rate of green tea catechins components and tea polyphenol.Different fixation processes(rotary drumfiring,microwave,steam-blasting),rolling process(weight of rolling,gently press rolling and traditional rolling),drying process(stove drying,roasting dehydration,baked fried drying) were adopted.The effect of different tea processing technology on the retention rate of catechins component and tea polyphenol was analyzed.It showed that the microwave fixation process,gently press rolling process,baked fried dry process were beneficial to keep high levels of EGCG,C,EGC,EC,ECG.

Adsorption Isotherms of Quercetin and Catechin Compounds on Quercetin-MIP

A molecular imprinted polymer（MIP） was prepared with quereetin as the template and methaerylie acid（MAA） as the functional monomer. Aeetonitrile and methanol were used as the porogen with ethylene glycol dimethaerylate （EGDMA） as the erosslinker and 2,2＇-azobis （ isobutyronitrile ） （ AIBN ） as the initiator. The experimental parameters of the equilibrium isotherms were estimated via linear and nonlinear regression analyses. The linear equadon as the functions of the adsorption concentration of the single compound in its solution and the competitive adsorption of the single compound in its mixed compounds solution was then expressed, and the adsorption equilibrium data were correlated to Langmuir and Freundlich isotherm models. The mixture compounds show competitive adsorption on the specific binding sites of quereetin-MIP. Furthermore, the competitive Langmnir isotherms were applied to the mixture compounds. The adsorption concentrations of quercetin, （＋）eatechin（＋C）, and （-）epieateehin（EC） on the quercetin molecular imprinted polymer were compared. The quercetin-imprinted polymer shows extraordinarily higher adsorption ability for quercetin than for the two eateehin compounds that were also assessed.

Catechins Green Tea GMB4 Clone Increases mRNA of ABCA1 through LXR Signaling in Cultured Macrophage Exposed OX-LDL

Inhibition of atherogenesis through inhibition of lipid metabolism has not been explored while other inhibitions through inflammation, endothelial dysfunction and free radicals have done. Inhibition of atherogenesis via inhibition of lipid metabolism can be done through the mechanism of Reverse Cholesterol Transport (RCT). Signaling pathways that play a role in this mechanism is LXR signaling. LXR activation by an LXR agonist led increasing cholesterol efflux. Catechins based on bioinformatics study showed as a potent candidate LXR agonists that can be used as an inhibitor of atherogenesis. This study aims to prove that the administration Catechins green tea Clone GMB4 can prevent atherosclerosis through increasing mechanism cholesterol efflux from macrophage by taking effect of ABCA1, ABCG1, SRB1 gene expression in cultured macrophages were exposed ox-LDL. Long-term goals of the outcome of the research are the use of Catechins Green Tea Clones GMB4 as an inhibitor of atherogenesis so that it can be used as a complementary therapy for the treatment of atherosclerosis and cardiovascular diseases. The research is divided into 5 groups, namely the culture of macrophages without exposed ox-LDL, culture exposed ox-LDL and groups of Catechins dose I, II, III. In vitro study showed that administration of Catechins increases mRNA of ABCA1, whereas mRNA ABCG1 and SRB1 decreased at all three doses given. The result of protein profilling was identified a protein with a molecular weight of 70 kDa by SDS-PGE with silver staining.

Tyrosinase Biosensor Used for the Determination of Catechin Derivatives in Tea: Correlation with HPLC/DAD Method

Tea, one of the most popular consumed worldwide beverages, is known to be rich in polyphenols, more particularly in catechins. An amperometric biosensor based on tyrosinase was developed in order to monitor the phenolic content in black and green teas. The enzyme was immobilised by coreticulation with glutaraldehyde on carbon screen-printed electrodes (CSPE). Initially, the performances of the biosensor were evaluated referring to catechol as a model substrate. This analytical tool exhibits a high sensitivity (217 nA/μM), low limit of detection (LOD) = 0.03 μM, good intra-electrode and inter-electrode reproducibilities with RSD lower than 3% (n = 5 injections) and RSD = 8.14% (n = 12 sensors) respectively. The storage stability was also studied;the biosensor retained successively 85% and 70% of its initial response after 34 and 53 days. Subsequently, several catechin derivatives frequently found in teas were tested and classified relatively to their sensitivities. For tea samples, the results obtained with the biosensors were compared to high performance liquid chromatography (HPLC) analysis. A good correlation between the two methods was obtained. The calculated recovery was between 90% and 96%, proving that the proposed tyrosinase biosensor can be an alternative analytical tool for global determination of catechin derivatives in tea.

Quantitation of the Total Catechin Content in Oils Extracted from Seeds of Selected Tea (<i>Camellia sinensis</i>(L) O. Kuntze, Theaceae) Clones by RP-HPLC

Catechins (flavan-3-ols) are polyphenolic plant secondary metabolites that have been strongly associated with a wide variety of beneficial health effects in vitro, in vivo and clinically. This study reports findings on the content of catechins in tea seed oil (TSO) extracted by Soxhlet extraction from seeds of different clones of Kenyan tea. Extraction of catechins from the crude oils was achieved by sequential liquid-liquid extraction (LLE) using methanol and quantified by reverse phase High Performance Liquid Chromatography (RP-HPLC). Results obtained revealed that all the crude test oils contained catechins, with oils extracted from clones TRFK K-Purple and GW-Ejulu having the highest total catechin content of 9.8 ± 0.25 and 9.0 ± 0.83 (×10-3% flavonoids) respectively. Statistically significant differences (p < 0.05) were evident in the total catechin contents of crude oils extracted from tea seeds with those extracted from corn, sunflower and soybean seeds. Moreover, clonal variations were evident, as the total catechin contents of oils extracted from clones TRFK K-Purple and GW-Ejulu were statistically different (p < 0.05) from those extracted from clones TRFK 301/3, TRFK 301/4, TRFK 301/5, TRFK 306, TRFK 91/1 and TRFCA SFS 150. Thus, the current findings strongly suggest that oils from seeds of Kenyan tea cultivars can be a potential source of potent natural antioxidants.

Variation in Catechin Composition of Popularly Cultivated Tea Clones in East Africa (Kenya)

Tea polyphenols and catechins have gained prominence in determination of tea quality. Tea leaves contain large amounts of catechins and their derivatives and these have shown positive effects on human health. An experiment was carried out to determine the level of catechins and polyphenols in 20 new clones found in two distinct tea growing areas. The trial comprising twenty clones was established in two distinct sites in Kenya using randomized complete block design with three replicates and consisted of 10 popular cultivars widely cultivated in the Lake Victoria Basin and additional 10 newly improved clones. Tea leaf samples were collected across two seasons;dry and wet seasons. Tea quality parameters entailing catechins, caffeine and total polyphenols was generated for the 20 clones across the two seasons and sites. The ISO 14502-1 and ISO 14502-1:2005 procedures were used for polyphenol and catechin analyses, respectively. The ANOVA results generated indicated that the level of catechins and polyphenols in tea were significantly different (p 0.05) and varietal dependent. Generally, the assam varieties had higher levels of catechins and polyphenols than the chinary and cambod varieties, indicating why they are popularly cultivated in the East African region and whose tea quality is highly regarded. Furthermore, the results from principle component analysis (PCA) grouped the clones into three major clusters with one comprising of high quality assam varieties, a mixture of moderate quality assam, cambod and chinary varieties and low catechin content assam anthocyanin-rich variety. It is concluded that the level of catechins in tea plants are varietal dependent, although environmental stress has effects on the synthesis of flavanoids. The results demonstrated that the differences in the accumulation of catechins among the tea clones could be important for the discrimination of clonal diversity.