scholarly journals Further investigation of the biosynthesis of caffeine in tea plants (Camellia sinensis L.). Methylation of transfer ribonucleic acid by tea leaf extracts

1976 ◽  
Vol 160 (2) ◽  
pp. 181-184 ◽  
Author(s):  
T Suzuki ◽  
E Takahashi
Keyword(s):  
Nucleic Acids ◽  
Ammonium Acetate ◽  
Tea Leaves ◽  
Leaf Extracts ◽  
Thiol Compounds ◽  
Caffeine Biosynthesis ◽  
Trna Methyltransferase ◽  
Tea Plants ◽  
Tea Leaf

1. The tRNA methyltransferase activity in vitro of leaves, cotyledons and roots of 85-day-old tea seedlings was studied. 2. The activity of extracts prepared from tea leaves with Polycar AT (insoluble polyvinylpyrrolidine) had optimum pH7.7 and was greatly influenced by thiol compounds, but only slightly by metal ions and ammonium acetate. 3. The activities of extracts, expressed per mg of protein, were as follows: roots greater than leaves greater than cotyledons. The only methylated base isolated after incubation with these preparations was 1-methyladenine. 4. The results did not support the view of involvement of methylation of nucleic acids in caffeine biosynthesis in tea plants. In contrast, it is suggested that theophylline is synthesized from the specific methylated precursor in nucleic acids, namely 1-methyladenylic acid, via 1-methylxanthine.

scholarly journals Biosynthesis of caffeine by tea-leaf extracts. Enzymic formation of theobromine from 7-methylxanthine and of caffeine from theobromine

1975 ◽  
Vol 146 (1) ◽  
pp. 87-96 ◽  
Author(s):  
T Suzuki ◽  
E Takahashi
Keyword(s):  
Shoot Formation ◽  
Nucleic Acid Metabolism ◽  
Methyl Groups ◽  
Leaf Extracts ◽  
Ph Optimum ◽  
Caffeine Biosynthesis ◽  
Purine Ring ◽  
Tea Plants ◽  
Tea Leaf ◽  
Chelating Reagents

1. Extracts prepared from tea leaves with Polyclar AT (insoluble polyvinylpyrrolidine) contained two methyltransferase activities catalysing the transfer of methyl groups from S-adenosylmethionine to 7-methylxanthine, producing theobromine, and to theobromine, producing caffeine. 2. The methyltransferases exhibited the same pH optimum (8.4) and a similar pattern of effects by metal ions, thiol inhibitors and metal-chelating reagents, both for theobromine and caffeine synthesis. Mg2+, Mn2+ and Ca2+ slightly stimulated enzyme activity but they were not essential. Paraxanthine was shown to be most active among methylxanthines, as the methyl acceptor. However, the formation of paraxanthine from 1-methylxanthine was very low and that from 7-methylxanthine was nil, suggesting that the synthesis of caffeine from paraxanthine is of little importance in intact plants. Xanthine, xanthosine, XMP and hypoxanthine were all inactive as methyl acceptors, whereas [2(-14)C]xanthine and [8(-14)C]hypoxanthine were catabolized to allantoin and urea by tea-leaf extracts. The apparent Km values are as follows: 7-methylxanthine, 1.0 times 10(-14)M; theobromine, 1.0 times 10(-3)M; paraxanthine, 0.2 times 10(-3)M; S-adenosylmethionine, 0.25 times 10(-4)M (with each of the three substrates). 3. The results suggest that the pathway for caffeine biosynthesis is as follows: 7-methylxanthine leads to theobromine leads to caffeine. In contrast, it is suggested that theophylline is synthesized from 1-methylxanthine. The methyl groups of the purine ring of caffeine are all derived directly from the methyl group of S-adenosylmethionine. Little is known about the pathways leading to the formation of 7-methylxanthine. 4. A good correlation between caffeine synthesis and shoot formation or growth of tea seedlings was shown, suggesting that the methylating systems in caffeine synthesis are closely associated with purine nucleotide and nucleic acid metabolism in tea plants.

scholarly journals SEASONAL VARIATIONS IN ANTIOXIDANT CAPACITIES AND PHENOLIC CONTENTS OF TEA LEAF EXTRACTS

2020 ◽  
pp. 108-112
Author(s):  
TEMSURENLA JAMIR ◽  
AJUNGLA T
Keyword(s):  
Seasonal Variations ◽  
Health Benefit ◽  
Dpph Assay ◽  
Tea Leaves ◽  
Leaf Extracts ◽  
Total Polyphenol ◽  
Phenolic Contents ◽  
Antioxidant Capacities ◽  
Reducing Ability ◽  
Tea Leaf

Objectives: The objective of the study was to estimate the seasonal variations in the antioxidant capacities, total polyphenol content (TPC), total flavonoid content (TFC), and tannin content (TC) of tea leaf extracts from two different plantation sites. Methods: Samples were collected from two tea gardens in Tuli and Ungma situated at N 26°39’19.3 E 094°39’22.7 and N 26°17’30.6 E 094°28’29.2, respectively, under the Mokokchung district of Nagaland, India. TPC, TFC, and TC from sample extracts were determined using Folin–Ciocalteu reagent, aluminum chloride colorimetric, and Folin–Ciocalteu assay. Apart from these, antioxidant capacities were analyzed using ferric reducing ability of plasma (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Results: The concentrations of total polyphenol, flavonoid, and tannin varied from 552.029±8.079 to 305.647±1.744 mg gallic acid equivalent/g, 238.770±0.508–148.457±1.653 mg catechin equivalent/g, and 26.453±0.485–20.173±0.173 mg tannic acid equivalent/g, respectively. FRAP and DPPH assay displayed value ranging from 2.564±0.023 to 1.074±0.023 mmol Fe(II) equivalent/g and 3.612±0.053–2.076±0.028 mmol Trolox equivalent/g. Significant seasonal variations in concentrations of these compounds were observed and a positive correlation between antioxidant capacities and phenolics of tea leaf extracts was established. Conclusion: Tea (Camellia sinensis (L.) O. Kuntze) has been regarded as a plant of immense medicinal and therapeutic value since time immemorial. The tea leaf extracts analyzed in this study gave high TPC, TFC, and TC, as well as high antioxidant activity in terms of DPPH and FRAP value. Studying such properties in tea leaves contributes more to our understandings of health benefit potentials in tea leaves and the quality of tea leaves on the basis of seasons and sites where they are planted.

scholarly journals A study of tea leaves drying using dehumidification process and regeneration of liquid desiccant in a closed-cycle dehumidification-humidification

2018 ◽  
Vol 159 ◽  
pp. 02025 ◽  
Author(s):  
Eflita Yohana ◽  
Mohammad Endy Yulianto ◽  
Shofwan Bahar ◽  
Azza Alifa Muhammad ◽  
Novi Laura Indrayani
Keyword(s):  
Absolute Humidity ◽  
Tea Plant ◽  
Regeneration Process ◽  
Drying Process ◽  
Liquid Desiccant ◽  
Tea Leaves ◽  
Saturation Point ◽  
Air Stream ◽  
Tea Plants ◽  
Tea Leaf

Tea plants in Indonesia are derived from Carmelia sinensis var. assamica which contain catechin in quite high amount compared with other countries tea plant. Green tea is made by inactivating the oxidase / phenolase enzyme that presents in the fresh tea leaf buds from tea garden, by using hot steam to prevent the oxidation of the catechins. Drying process to reduce the moisture of tea, one of the method is by utilizing the dry air from dehumidification process. Liquid desiccant made from 50% concentration of CaCl2, the temperature is lowered to 10 °C and sprayed into the air stream which contains water vapor by using a 0.2 mm spraying nozzle so that mass transfer and latent heat occur in the dehumidifier. The result of air dehumidification process used for drying tea leaves. The air is able to dry the tea leaves from the weight of 58 grams to 47 grams. Then the liquid desiccant dehumidification process will be streamed into the humidifier, where the liquid desiccant regeneration process will have change into the initial concentration. The result of air humidification process has an average absolute humidity rise of 0.07 g/kg. The liquid desiccant regeneration process that happened continuously reaching the saturation point at 280 minutes. It can be concluded that the process of dehumidification-humidification is a fairly effective method for drying the tea leaves.

Methylation of Xanthosine by Tea-leaf Extracts and Caffeine Biosynthesis

1985 ◽  
Vol 49 (3) ◽  
pp. 887-890 ◽  
Author(s):  
Osamu Negishi ◽  
Tetsuo Ozawa ◽  
Hiroshi Imagawa
Keyword(s):  
Leaf Extracts ◽  
Caffeine Biosynthesis ◽  
Tea Leaf

scholarly journals Formation of α-Farnesene in Tea (Camellia sinensis) Leaves Induced by Herbivore-Derived Wounding and Its Effect on Neighboring Tea Plants

2019 ◽  
Vol 20 (17) ◽  
pp. 4151 ◽  
Author(s):  
Xuewen Wang ◽  
Lanting Zeng ◽  
Yinyin Liao ◽  
Jianlong Li ◽  
Jinchi Tang ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Nicotiana Benthamiana ◽  
Plant Volatiles ◽  
Tea Leaves ◽  
Related Factors ◽  
Geranyl Diphosphate ◽  
Herbivore Induced Plant Volatiles ◽  
Tea Plants ◽  
And Function

Herbivore-induced plant volatiles (HIPVs) play important ecological roles in defense against stresses. In contrast to model plants, reports on HIPV formation and function in crops are limited. Tea (Camellia sinensis) is an important crop in China. α-Farnesene is a common HIPV produced in tea plants in response to different herbivore attacks. In this study, a C. sinensis α-farnesene synthase (CsAFS) was isolated, cloned, sequenced, and functionally characterized. The CsAFS recombinant protein produced in Escherichia coli was able to transform farnesyl diphosphate (FPP) into α-farnesene and also convert geranyl diphosphate (GPP) to β-ocimene in vitro. Furthermore, transient expression analysis in Nicotiana benthamiana plants indicated that CsAFS was located in the cytoplasm and could convert FPP to α-farnesene in plants. Wounding, to simulate herbivore damage, activated jasmonic acid (JA) formation, which significantly enhanced the CsAFS expression level and α-farnesene content. This suggested that herbivore-derived wounding induced α-farnesene formation in tea leaves. Furthermore, the emitted α-farnesene might act as a signal to activate antibacterial-related factors in neighboring undamaged tea leaves. This research advances our understanding of the formation and signaling roles of common HIPVs in crops such as tea plants.

scholarly journals Metabolism of methionine and biosynthesis of caffeine in the tea plant (Camellia sinensis L.)

1976 ◽  
Vol 160 (2) ◽  
pp. 171-179 ◽  
Author(s):  
T Suzuki ◽  
E Takahashi
Keyword(s):  
Nucleic Acids ◽  
Gradient Centrifugation ◽  
Tea Plant ◽  
Shoot Tips ◽  
Purine Nucleotides ◽  
Unknown Compound ◽  
Caffeine Biosynthesis ◽  
Tea Shoot ◽  
Tea Plants ◽  
Almost All

1. Caffeine biosynthesis was studied by following the incorporation of 14C into the products of L-[Me-14C]methionine metabolism in tea shoot tips. 2. After administration of a ‘pulse’ of L-[Me-14C]methionine, almost all of the L-[Me-14C]methionine supplied disappeared within 1 h, and 14C-labelled caffeine synthesis increased throughout the experimental periods, whereas the radioactivities of an unknown compound and theobromine were highest at 3 h after the uptake of L-[Me-14C]methionine, followed by a steady decrease. There was also slight incorporation of the label into 7-methylxanthine, serine, glutamate and aspartate, disappearing by 36 h after the absorption of L-[Me-14C]methionine. 3. The radioactivities of nucleic acids derived from L-[Me-14C]methionine increased rapidly during the first 12 h incubation period and then decreased steadily. Sedimentation analysis of nucleic acids by sucrose-gradient centrifugation showed that methylation of nucleic acids in tea shoot tips occurred mainly in the tRNA fraction. The main product among the methylated bases in tea shoot tips was identified as 1-methyladenine. 4. The results indicated that the purine ring in caffeine is derived from the purine nucleotides in the nucleotide pool rather than in nucleic acids. A metabolic scheme to show the production of caffeine and related methylxanthines from the nucleotides in tea plants is discussed.

scholarly journals Research for toxicity and determination IC50 of tea leaf extracts on cervical cancer cell and breast cancer cell MCF7 by in vitro

2020 ◽  
Vol 3 (2) ◽  
pp. 80-86
Author(s):  
Van Anh Nguyen Thi ◽  
Thanh Nguyen Duc ◽  
◽  
Keyword(s):  
Breast Cancer ◽  
Cervical Cancer ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Gradient Elution ◽  
Breast Cancer Cell Lines ◽  
Control Group ◽  
Tea Leaves ◽  
Leaf Extracts

After extracting tea leaves with methanol 80% (acidified with HCl), the extraction was purified through two phases: the first stage used the column of silica gel with gradient elution, the second stage continued to be isolated on Sephadex LH-20 column with isometric elution mode, K powder was obtained. The test of toxicity of K powder on two MCF37 breast cancer cell lines and Hela cervical cancer was carried out and obtained the following results: IC50 of the composition with the line MCF37 was 31.62 µg/mL and with the line Hela was 50.1 µg/mL. Compared with the positive control group of Taxol showed that the efficacy of the obtained product was lower. However, this is a new direction in the use of drugs derived from plants in general and tea leaves in particular.

Search for Substances That Inhibit Histamine Production Using Used Tea Leaves

2020 ◽  
Vol 83 (10) ◽  
pp. 1789-1795
Author(s):  
NOBUYUKI TANAHASHI ◽  
MAKOTO AZAMA ◽  
MAI OTSUKA ◽  
FUMIYA OGINO ◽  
RYUHEI MAEDA ◽  
...  
Keyword(s):  
Green Tea ◽  
Detection Method ◽  
Histidine Decarboxylase ◽  
Tea Leaves ◽  
High Concentration ◽  
Leaf Extracts ◽  
Simple Method ◽  
Food Loss ◽  
Histamine Production ◽  
Tea Leaf

ABSTRACT As food waste has become a major problem in recent years, measures against food loss have become an urgent issue. When manufacturing or making green tea beverages, large quantities of tea leaves are subsequently disposed of, which results in potential food loss. Moreover, because many of the tea components remain in the used tea leaves, these continue to have value, as these leaves exhibit antibacterial action. Furthermore, histamine is produced from histidine via histidine decarboxylase that is produced by microorganisms, with histamine accumulation potentially causing histamine food poisoning. Although we have been trying to develop a simple method for detecting histamine, there has yet to be a quick detection method established. We examined whether a method using a low concentration of bromocresol indicator in the culture medium was capable of rapidly detecting histamine. Our results demonstrated that when using lower indicator concentrations, there was a faster detection of histamine production, within 4 h. Using this method, we also investigated whether used tea leaf components, which have antibacterial effects, could suppress histamine production. In this study, used leaves from green, oolong, and black teas were analyzed according to different extraction processes. Compared with green tea, oolong and black teas were able to suppress histamine production using lower concentrations, 25 and 12.5% extracts, respectively. In contrast, the inhibitory effect on histamine production by used green tea leaves required a high concentration of 50% used tea leaf extracts. Furthermore, our results suggested that used tea leaves suppress histamine production and that the inhibitory effects vary according to different extracts. Based on these findings, we propose that (i) a more rapid detection method for histamine should be established and (ii) used tea leaf extracts may have applications in the storage and processing of foods associated with an undesirable production of histamine. HIGHLIGHTS

scholarly journals Methylation of xanthosine by tea-leaf extracts and caffeine biosynthesis.

1985 ◽  
Vol 49 (3) ◽  
pp. 887-890 ◽  
Author(s):  
Osamu NEGISHI ◽  
Tetsuo OZAWA ◽  
Hiroshi IMAGAWA
Keyword(s):  
Leaf Extracts ◽  
Caffeine Biosynthesis ◽  
Tea Leaf

GROWTH AND DEVELOPMENT OF PRAIRIE GRAIN WIREWORM CTENICERA DESTRUCTOR BROWN (COLEOPTERA:ELATERIDAE), ON SYNTHETIC DIETS

1966 ◽  
Vol 44 (6) ◽  
pp. 995-1001 ◽  
Author(s):  
G. R. F. Davis
Keyword(s):  
Growth And Development ◽  
Water Extract ◽  
Ethanol Extract ◽  
Hot Water ◽  
Tea Leaves ◽  
Leaf Extracts ◽  
Hot Water Extract ◽  
Growth Promoting ◽  
Tea Leaf ◽  
Ctenicera Destructor

Larvae of Ctenicera destructor were fed nine synthetic diets for 6 months at 68 ± 2 °F and 75% relative humidity. Seven of the nine diets were based on a diet developed for larvae of Heliothis sp. It was modified by adding putrescine or spermidine, or both; hot-water or 70% ethanol extract of tea leaves; residue from hot-water extraction of tea leaves; or hot-water extract of germinating rye seed. Two chemically defined diets based on a previously reported amino acid analysis of this wireworm were also formulated: one contained hot-water extract of germinating rye seed.More larvae survived on a diet supplemented with putrescine and spermidine, on one supplemented with hot-water or with ethanol extract of tea leaves, and on the unsupplemented chemically defined diet than on the other diets. They more than doubled their weight on a diet supplemented with putrescine and spermidine. Growth factors for C. destructor present in tea-leaf extracts and residue probably differ from those for Adoxophyes orana. Inhibitory and growth-promoting factors for C. destructor are apparently present in hot-water extract of germinating rye seed. Putrescine or spermidine, or both, or some related metabolic product, may be necessary for growth and development of C. destructor. Frequency of molting was not always indicative of dietary efficiency.

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