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1.
Plant Physiol Biochem ; 195: 58-66, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36603449

RESUMEN

The current study focused on the tissues of wild Rosa webbiana from different altitudes of Indian Western Himalayas for vitamin C content, total phenolics, flavonoids, total sugars, and antioxidant potential. To date, there are very few studies on underutilized tissues viz. fruits, leaves and stem of Rosa webbiana growing in the higher altitudes. The targeted UHPLC-QTOF-IMS illustrated the phenolics fingerprinting of tissue extracts. Twelve bioactive compounds were detected with quercetin, kaempferol, and their derivatives dominantly in stem and leaves. The results have revealed that fruits possessed the highest vitamin C, and sugar contents (960, and 191.6 mg/100 g, respectively). Compared to other tissues, leaves showed the highest total phenolics as well as best results in vitro assays employed to assess antioxidant potential. The antioxidant activity showed a positive correlation with total phenolics. A significant variation in total phenolics, total flavonoids, and antioxidant potential was mainly attributed to oxidative stress on plants due to altitude difference, and secondary metabolite production. Taken together, the underutilized tissues of Rosa webbiana could be exploited as a promising, low-cost resource of phenolic compounds in food, cosmetic, and pharmaceutical industries. Our study will pave the way to developing food products from Rosa webbiana, a natural source for health-conscious people.


Asunto(s)
Antioxidantes , Rosa , Cromatografía Líquida de Alta Presión , Flavonoides/análisis , Fenoles/análisis , Ácido Ascórbico , Extractos Vegetales
3.
Eur J Nutr ; 58(7): 2943-2957, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30607562

RESUMEN

PURPOSE: In the present study, we systematically identified and evaluated a synbiotic combination of phytochemical epigallocatechin gallate (EGCG) and probiotic bacteria in amelioration of immunosenescence and oxidative stress in aged mice. METHODS: Inhibitory effects of EGCG against different bacterial species were evaluated in vitro, followed by analysis to identify potential combination of EGCG and probiotic bacteria against alleviation of oxidative and inflammatory stress ex vivo. The best synbiotic combination, vis-à-vis prebiotic and probiotic supplementation alone, was then evaluated in aged Swiss albino mice for modulation of various immunological and antioxidative parameters. RESULTS: EGCG strongly inhibited the growth of pathogenic microbes as compared to probiotic bacteria. A combination of EGCG with probiotic Lactobacillus fermentum (LF) provided evidence of additive effects in the amelioration of oxidative and inflammatory stress-induced cell death. In vivo study revealed that combined supplementation of LF and EGCG significantly enhanced neutrophil oxidative index, CD3+ cell numbers and activation status, Th1/Th2 cytokines in splenic supernatants as well as liver Nrf-2 expression in comparison with treatments with LF or EGCG alone. The combined application of EGCG and LF did not simply result in additive or synergistic effects in relation with individual treatments. CONCLUSION: These observations suggest that EGCG could be considered as a potential prebiotic that can offer second generation synbiotic health beneficial effects for the alleviation of some of the deleterious aspects of immunosenescence and aging.


Asunto(s)
Envejecimiento/efectos de los fármacos , Antioxidantes/farmacología , Catequina/análogos & derivados , Dieta/métodos , Inmunidad Celular/efectos de los fármacos , Limosilactobacillus fermentum , Probióticos/farmacología , Animales , Antioxidantes/administración & dosificación , Catequina/administración & dosificación , Catequina/farmacología , Modelos Animales de Enfermedad , Inmunosenescencia/efectos de los fármacos , Masculino , Ratones , Estrés Oxidativo/efectos de los fármacos , Probióticos/administración & dosificación , Simbióticos/administración & dosificación
4.
Food Chem ; 242: 601-610, 2018 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-29037735

RESUMEN

l-theanine (l-Th), a non-protein amino acid present in tea, is a valuable nutraceutical product with unique health benefits and used as an additive in food industry. l-Th enhances the umami taste but its use is limited due to its inadequate production. Different extraction approaches from tea shoots, chemical synthesis to microbial transformation have been tried to meet its demand. In vitro, in vivo as well as clinical studies have shown its positive effect in regulating CNS disorders. l-Th has become choice ingredient in CNS active products due to its anti-stress and neuroprotective role in dementias particularly in retrogression of Alzheimer's. l-Th biochemically modulates various anti-neoplastic agents by increasing their bioavailability in tumour cells. The review, is an effort to condense the recent research on l-Th highlighting its biological resource, plausible role in tea plant, production approaches, its physiological role on human health and future prospects.


Asunto(s)
Camellia sinensis/química , Glutamatos/análisis , Té/química , Animales , Humanos , Gusto
5.
Biogerontology ; 18(3): 367-382, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28341876

RESUMEN

The present investigation assessed the potential of green tea phytochemical epigallocatechin-3-gallate (EGCG) in alleviating age-associated aberrations in immunity, hypothalamus-pituitary-adrenal (HPA) axis and redox homeostasis using 16 months old male Swiss albino mice. Four groups of animals (n = 6 per group) were supplemented with either aqueous EGCG at 25, 50 and 100 mg/kg/animal or vehicle control for 6 weeks. A concurrent analysis of CD4+ and CD8+ lymphocytes in splenocytes, differential leucocyte population, T cell differentiation markers in peripheral blood mononuclear cells (PBMCs), neutrophil functions, immunoglobulins profile in intestine, circulatory HPA axis hormonal levels as well as inflammatory and oxidative stress in the liver was performed. We observed a remarkable increase in plasma dehydroepiandrosterone (DHEA) levels of 100 mg EGCG fed animals while eosinophils and monocytes counts in blood increased. EGCG consumption increased the fraction of CD3+CD8+ cells in splenocytes and CD28 expression on PBMCs. The immunoglobulins profile revealed decreased production of secretory IgA, IgE and IgG1/IgG2a ratio. Liver extracts showed increase in superoxide dismutase activity and total antioxidant capacity while lipid peroxidation along with inflammatory markers (IL-6 and TNF-α) decreased. Our results collectively show that EGCG consumption during aging strengthens systemic immunity by enhancing cellular immune response and simultaneously attenuating antibody response aided by an increase in adrenal DHEA production. Thus, consumption of green tea may be beneficial in alleviating some of the deleterious aspects of aging and immunosenescence in elderly.


Asunto(s)
Envejecimiento , Formación de Anticuerpos/efectos de los fármacos , Antioxidantes/farmacología , Catequina/análogos & derivados , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Inmunidad Celular/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Té/química , Animales , Catequina/administración & dosificación , Catequina/farmacología , Deshidroepiandrosterona/sangre , Relación Dosis-Respuesta a Droga , Inmunoglobulinas/metabolismo , Recuento de Leucocitos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Estrés Oxidativo/efectos de los fármacos , Reacción en Cadena en Tiempo Real de la Polimerasa
6.
Neural Netw ; 71: 142-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26356597

RESUMEN

The paper presents a novel encoding scheme for neuronal code generation for odour recognition using an electronic nose (EN). This scheme is based on channel encoding using multiple Gaussian receptive fields superimposed over the temporal EN responses. The encoded data is further applied to a spiking neural network (SNN) for pattern classification. Two forms of SNN, a back-propagation based SpikeProp and a dynamic evolving SNN are used to learn the encoded responses. The effects of information encoding on the performance of SNNs have been investigated. Statistical tests have been performed to determine the contribution of the SNN and the encoding scheme to overall odour discrimination. The approach has been implemented in odour classification of orthodox black tea (Kangra-Himachal Pradesh Region) thereby demonstrating a biomimetic approach for EN data analysis.


Asunto(s)
Nariz Electrónica , Redes Neurales de la Computación , Odorantes , , Algoritmos , Biomimética , Diseño de Equipo , Distribución Normal , Nariz , Percepción Olfatoria
7.
Food Chem ; 176: 357-66, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-25624244

RESUMEN

Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purple tea varieties developed in Kangra valley was assessed, and compared with the quality of tea from standard Kangra clone. Purple tea shoots (PL) recorded higher amount of polyphenols compared to standard green tea shoot (GL) while epigallocatechin gallate (EGCG) recorded higher levels in GL. Higher levels of theaflavins were recorded in orthodox black tea from purple shoots (BTP) compared to black tea (BT) made from green shoots. Both theanine and caffeine recorded higher levels in GL. Volatile flavour profiles of these teas showed qualitative and quantitative differences. Aroma extract dilution assay showed higher dilution factors in BTP than BT. Orthodox teas from purple shoots exhibited higher antioxidant activity compared to standard black tea. Strong correlation of total quality scores with aroma and infusion colour was observed. Tea from anthocyanin-rich cultivars can become specialty teas with high antioxidant activity.


Asunto(s)
Antocianinas/química , Antioxidantes/análisis , Extractos Vegetales/química , Hojas de la Planta/química , Té/química , India , Polifenoles
8.
Food Chem ; 167: 290-8, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25148991

RESUMEN

The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography-olfactometry-mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, ß-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography-olfactometry-mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, ß-ionone, hotrienol and dihydroactinidiolide to be odour active components.


Asunto(s)
Odorantes/análisis , Té/química , Fraccionamiento Químico
9.
Transgenic Res ; 23(2): 211-23, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23982743

RESUMEN

Drought is a major stress that affects the yield and quality of tea, a widely consumed beverage crop grown in more than 20 countries of the world. Therefore, osmotin gene-expressing transgenic tea plants produced using earlier optimized conditions were evaluated for their tolerance of drought stress and their quality. Improved tolerance of polyethylene glycol-induced water stress and faster recovery from stress were evident in transgenic lines compared with the normal phenotype. Significant improvements in growth under in-vitro conditions were also observed. Besides enhanced reactive oxygen species-scavenging enzyme activity, the transgenic lines contained significantly higher levels of flavan-3-ols and caffeine, key compounds that govern quality and commercial yield of the beverage. The selected transgenic lines have the potential to meet the demands of the tea industry for stress-tolerant plants with higher yield and quality. These traits of the transgenic lines can be effectively maintained for generations because tea is commercially cultivated through vegetative propagation only.


Asunto(s)
Adaptación Biológica/genética , Camellia sinensis/genética , Sequías , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Estrés Fisiológico/genética , Análisis de Varianza , Cafeína/análisis , Camellia sinensis/crecimiento & desarrollo , Camellia sinensis/metabolismo , Cromatografía Líquida de Alta Presión , Flavonoides/análisis , Depuradores de Radicales Libres/metabolismo , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Polietilenglicoles , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
J Nanosci Nanotechnol ; 13(10): 6767-72, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24245141

RESUMEN

Twelve different orthodox Indian tea samples were collected from tea growing and processing sites of Kangra (Valley), India. The percentage of major chemical constituents responsible for the tea quality has been determined by HPLC and UV-vis spectrophotometer. Impedance response using Platinum (Pt), Gold (Au), Silver (Ag), Glassy Carbon (GC), Polyaniline (PANI) (emraldine salt) and Poly Pyrrole (PPY) working electrodes in tea infusions in the frequency range of 1 Hz to 100 kHz has been measured for 30 days on each tea sample. The impedance response of these working electrodes along with the determined chemical concentrations was subjected to Principal Component Analysis (PCA). It was possible to map the antioxidant levels in these tea samples with few exceptions from the score plot of PCA.


Asunto(s)
Impedancia Eléctrica , Té/química , Compuestos de Anilina/química , Carbono/química , Cromatografía Líquida de Alta Presión , Metales/química , Polímeros/química , Análisis de Componente Principal , Pirroles/química , Espectrofotometría Ultravioleta
11.
Appl Biochem Biotechnol ; 170(7): 1649-64, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23712792

RESUMEN

The first step in Agrobacterium tumefaciens infection of plants is the establishment of cell-cell contact between the two partners. However, failure to establish such contact makes many plants and explants recalcitrant to A. tumefaciens infection. Tea is one such example where even the popular inducer, acetosyringone failed to facilitate A. tumefaciens infection due to the presence of high amounts of bactericidal/bacteriostatic polyphenols. Quinones are formed as a result of polyphenols oxidation. They cause tissue browning and necrosis during the process of transformation, and in turn prevent A. tumefaciens infection. Compounds such as polyphenol adsorbents, i.e., polyvinylpyrrolidone and charcoal, and antioxidants like cysteine and ascorbic acid were screened to overcome tissue browning. Although these compounds enhanced the growth of A. tumefaciens, these failed to facilitate the infection of the leaves of either Kangra Jat, Tocklai Variety-1, UPASI-9, UPASI-10, and Stock-449 cultivars of tea. On the contrary, the presence of filter sterilized L-glutamine and L-glutamic acid in the co-cultivation medium facilitated successful A. tumefaciens infection of recalcitrant tea leaves. L-Glutamine and glutamic acid form harmless adducts by binding to quinones. Therefore, their presence in the co-cultivation medium allowed the tea leaves to remain living and appealing to the infecting A. tumefaciens. Successful A. tumefaciens infection of tea leaves was confirmed by positive signals in GUS assay, PCR, and Dot blot.


Asunto(s)
Agrobacterium tumefaciens/fisiología , Camellia sinensis/microbiología , Camellia sinensis/fisiología , Ácido Glutámico/farmacocinética , Glutamina/farmacocinética , Plantas Modificadas Genéticamente/microbiología , Plantas Modificadas Genéticamente/fisiología , Transfección/métodos
12.
Int J Med Mushrooms ; 15(1): 49-56, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23510284

RESUMEN

Five wild culinary-medicinal species of genus Pleurotus (Fr.) P. Kumm. (P. floridanus Singer, P. pulmonarius (Fr.) Quél., P. sapidus Quél., P. cystidiosus O.K. Miller, and P. sajor-caju (Fr.) Singer), collected from different localities of Northwest India, were studied for their nutritional and nutraceutical composition. Composition analysis of nutrients involved determining proteins, fats, ash, fiber, and carbohydrates using standard biochemical techniques. Minerals were estimated by an atomic absorption spectrophotometer and toxic metals were determined by the Reinsch test method. The analysis of nutraceuticals included determination of sugars by high-performance liquid chromatography, fatty acids by gas chromatography, and antioxidants such as ß-carotene, lycopene, and total phenolic compounds with methanolic extract using a colorimetric assay. In the samples analyzed, carbohydrates dominated over protein and other macronutrients. Carbohydrates ranged from 85.86 to 88.38%, protein 0.98 to 2.17%, crude fat 0.62 to 0.84%, crude fibers 2.76 to 3.12%, and ash content 1.03 to 2.20%. Macro- and microminerals (calcium, magnesium, sodium, potassium, copper, zinc, and iron) also were found in substantial amount, whereas toxic metals (lead, silver, arsenic, mercury, and antimony) were not detected. Three main sugars-sucrose (0.338-2.011%), glucose (0.553-0.791%), and xylose (0.01%)-were detected. Among fatty acids, monounsaturated fatty (37.17-68.29%) acids were documented in a higher proportion than saturated fatty acids (26.07-47.77%). In terms of antioxidant composition, all species contained ascorbic acid, phenols, carotene, and lycopene. Ascorbic acid content ranged from 0.46 to 0.49 mg/100 g, total phenolic compounds ranged from 6.76 to 16.92 mg/100 g of gallic acid, ß-carotene ranged from 0.134 to 0.221 µg/100 g, and lycopene from 0.055 to 0 .075 µg/100 g.


Asunto(s)
Suplementos Dietéticos/análisis , Valor Nutritivo , Pleurotus/química , Pleurotus/clasificación , Ácido Ascórbico/química , Carbohidratos/química , Ácidos Grasos/química , India , Metales/análisis , Fenoles/química , Especificidad de la Especie , beta Caroteno/química
13.
Nat Prod Commun ; 6(8): 1155-8, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21922925

RESUMEN

Volatile flavour components of tea flowers (Camellia sinensis) were isolated by two methods viz. simultaneous distillation extraction (SDE), supercritical fluid extraction (SFE), analyzed by GC and GC/MS and compared with headspace analysis (HS). The composition of the volatile components extracted by the three methods differed considerably. In SFE, phenylethanol (14.7%), linalool (7.9%), (E)-linalool oxide furanoid (3.5%), epoxy linalool (1.6%), geraniol (2.3%) and hotrienol (1.5%) were major components. m-Xylene (2.6%), (E)-linalool oxide pyranoid (5.4%), p-myrcene (5.2%), alpha-cadinol (4.3%) and methyl palmitate (2.9%) were major compounds isolated by SDE. 3-hexenol (2.1%) (E)-4,8-dimethyl-1,3,7-nonatriene (20.9%) and linalool (35.1%) are major components in headspace analysis. Acetophenone and pheromone germacrene D is detected in tea flowers by all the methods studied. Floral, fresh and fruity odour of tea flowers is retained by SFE as there is very little loss of heat sensitive volatiles in SFE. The flavour isolated from SFE has superior quality compared to SDE.


Asunto(s)
Camellia sinensis/química , Flores/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Compuestos Orgánicos Volátiles/química , Cromatografía con Fluido Supercrítico , India
14.
J Microbiol Biotechnol ; 20(12): 1724-34, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21193830

RESUMEN

A phosphate-solubilizing bacterial strain isolated from Hippophae rhamnoides rhizosphere was identified as Rahnella sp. based on its phenotypic features and 16S rRNA gene sequence. The bacterial strain showed the growth characteristics of a cold-adapted psychrotroph, with the multiple plant growth-promoting traits of inorganic and organic phosphate solubilization, 1-aminocyclopropane-1- carboxylate-deaminase activity, ammonia generation, and siderophore production. The strain also produced indole- 3-acetic acid, indole-3-acetaldehyde, indole-3-acetamide, indole-3-acetonitrile, indole-3-lactic acid, and indole-3- pyruvic acid in tryptophan-supplemented nutrient broth. Gluconic, citric and isocitric acids were the major organic acids detected during tricalcium phosphate solubilization. A rifampicin-resistant mutant of the strain exhibited high rhizosphere competence without disturbance to the resident microbial populations in pea rhizosphere. Seed bacterization with a charcoal-based inoculum significantly increased growth in barley, chickpea, pea, and maize under the controlled environment. Microplot testing of the inoculum at two different locations in pea also showed significant increase in growth and yield. The attributes of coldtolerance, high rhizosphere competence, and broad-spectrum plant growth-promoting activity exhibited the potential of Rahnella sp. BIHB 783 for increasing agriculture productivity.


Asunto(s)
Hippophae/microbiología , Indoles/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Raíces de Plantas/microbiología , Rahnella/clasificación , Rahnella/fisiología , Rizosfera , Amoníaco/metabolismo , Cicer/crecimiento & desarrollo , Cicer/microbiología , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Hippophae/crecimiento & desarrollo , Hordeum/crecimiento & desarrollo , Hordeum/microbiología , Datos de Secuencia Molecular , Fosfatos/metabolismo , Filogenia , ARN Ribosómico 16S/genética , Rahnella/genética , Rahnella/aislamiento & purificación , Análisis de Secuencia de ADN , Sideróforos/metabolismo , Zea mays/crecimiento & desarrollo , Zea mays/microbiología
15.
Chem Biodivers ; 6(7): 1042-52, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19623550

RESUMEN

The heterogeneous Indian tea germplasm includes 'China', 'Assam', 'Cambod', and their hybrids which were evaluated using biochemical markers viz., total catechin and their fractions, for varietal identification and characterization. Principal component analysis (PCA) of biochemical characters showed that the total catechin and trihydroxylated catechin has higher eigenvalues. The first two principal components (PCs) could differentiate more than 90% of the clones studied. This grouping based on first two principal component matrices differentiated 'China', and their hybrids with 'Assam' and 'Cambod' variety. Morphologically indistinct large-leaved 'Cambod' variety and 'Assam' varieties could not be differentiated using biochemical markers, since both varietal types taxonomically belong to a single species. Clones of 'China' type showed low total catechin content and catechin ratio which are distinctly grouped. The 'China-Assam' and 'China-Cambod' hybrids formed intermediate groups between 'China' PC group and 'Cambod'/'Assam' PC groups, providing evidence for genetic control of catechin ratio variation. Tea clones which are differentially positioned in the PC group could be explained based on the genetic contribution by other varietal type as parents. This biochemical characterization will be a useful tool in the development of quality-tea clones with different proportion of total catechin and their fractions.


Asunto(s)
Camellia sinensis/química , Catequina/análogos & derivados , Catequina/análisis , Té/química , Biomarcadores/análisis , Catequina/química , India , Análisis de Componente Principal
16.
Mol Biotechnol ; 43(2): 104-11, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19479388

RESUMEN

To study caffeine biosynthesis and degradation, here we monitored caffeine synthase gene expression and caffeine and allantoin content in various tissues of four Camellia sinensis (L.) O. Kuntze cultivars during non-dormant (ND) and dormant (D) growth phases. Caffeine synthase expression as well as caffeine content was found to be higher in commercially utilized tissues like apical bud, 1st leaf, 2nd leaf, young stem, and was lower in old leaf during ND compared to D growth phase. Among fruit parts, fruit coats have higher caffeine synthase expression, caffeine content, and allantoin content. On contrary, allantoin content was found lower in the commercially utilized tissues and higher in old leaf. Results suggested that caffeine synthesis and degradation in tea appears to be under developmental and seasonal regulation.


Asunto(s)
Cafeína/biosíntesis , Cafeína/química , Camellia sinensis/química , Camellia sinensis/metabolismo , Estaciones del Año , Camellia sinensis/crecimiento & desarrollo
17.
Tree Physiol ; 29(6): 837-46, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19380395

RESUMEN

Tea [Camellia sinensis (L.) O. Kuntze] leaves are a major source of epicatechin (EC) and its gallolyl derivatives epicatechin gallate, epigallocatechin and epigallocatechin gallate, collectively known as epicatechins (ECs). Epicatechins are important factors determining tea quality, and they also possess many medicinal properties. To gain further information about the regulation of the biosynthesis of ECs, we cloned the gene encoding anthocyanidin reductase from tea (CsANR) by first quantifying changes in the concentrations of ECs in response to drought, gibberellic acid (GA(3)), abscisic acid (ABA) and wounding treatments, followed by differential display of mRNAs and analysis of those bands exhibiting a change in expression paralleling the treatment-induced changes observed in the EC data. Analysis of 133 bands yielded a partial cDNA of CsANR that was later cloned to the full length by rapid amplification of the cDNA ends. The full-length CsANR (Accession No. AY641729) comprised 1233 bp with an ORF of 1014 bp (from 79 to 1092 bp) encoding a polypeptide of 337 amino acids. Expression of CsANR in an Escherichia coli expression vector yielded a functional protein that catalyzed the conversion of cyanidin to EC in the presence of NADPH. Analysis of ECs and gene expression in leaves at different developmental stages and across five tea clones exhibiting variable concentrations of ECs revealed a positive correlation between concentration of ECs and CsANR expression. Expression of CsANR was down-regulated in response to drought, ABA and GA(3) treatments and up-regulated in response to wounding.


Asunto(s)
Camellia sinensis/enzimología , Camellia sinensis/genética , Catequina/metabolismo , NADH NADPH Oxidorreductasas/genética , Proteínas de Plantas/genética , Ácido Abscísico/farmacología , Secuencia de Aminoácidos , Camellia sinensis/efectos de los fármacos , Sequías , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Giberelinas/farmacología , Datos de Secuencia Molecular , NADH NADPH Oxidorreductasas/química , NADH NADPH Oxidorreductasas/metabolismo , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido
18.
Funct Integr Genomics ; 9(1): 125-34, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18679731

RESUMEN

Phenylalanine ammonia-lyase and cinnamate 4-hydroxylase are important enzymes in allocating significant amounts of carbon from phenylalanine into the biosynthesis of several important secondary metabolites. Tea is an important crop of commerce known for its beverage and medicinally important flavonoid compounds, mainly catechins. As metabolic flux for the operation of the flavonoid pathway is maintained through the activities of PAL and C4H, thus, catechins biosynthesis in tea is critically dependent on the products of these enzymes. We examined the expression of PAL and C4H. Sequence encoding CsPAL was isolated from tea by polymerase chain reaction using sequence information available at the NCBI GenBank. Sequence encoding C4H was isolated from tea by using differential display of mRNA and rapid amplification of cDNA ends technology. CsC4H (AY641731) comprised of 1,352 bp full-length cDNA with open reading frame of 1,173 bp encoding 390 amino acids. Catechin contents decreased in response to drought stress (DS), abscisic acid (ABA), and gibberellic acid (GA(3)) treatments but increased in response to wounding. The expression of CsPAL and CsC4H showed the same behavior under the above treatments and was also in accordance with the catechin contents. A positive correlation between catechin contents and gene expression suggested a critical role of the enzymes in catechins biosynthesis and a crosstalk between phenylpropanoid and flavonoid pathways.


Asunto(s)
Camellia sinensis/enzimología , Catequina/metabolismo , Fenilanina Amoníaco-Liasa/metabolismo , Té/enzimología , Transcinamato 4-Monooxigenasa/metabolismo , Ácido Abscísico/farmacología , Northern Blotting , Camellia sinensis/efectos de los fármacos , Camellia sinensis/genética , Sequías , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Giberelinas/farmacología , Fenilanina Amoníaco-Liasa/genética , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Té/efectos de los fármacos , Té/genética , Factores de Tiempo , Transcinamato 4-Monooxigenasa/genética
19.
Biochem Genet ; 46(11-12): 810-9, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18784998

RESUMEN

To revive cultivation of the tea unique to the western Himalayan region, it is important to evaluate the seed-derived bushes available in the area's abandoned gardens. This study used quantitative leaf characters, catechin content, and AFLP markers to assess these China cultivar type bushes. Compared with other China cultivar germplasm, these accessions showed a higher level of diversity among themselves. Among the quantitative morphological characters, leaf length is important in distinguishing the accessions studied, with a high loading value in the principal component analysis. The catechins and AFLP markers displayed the genetic makeup of the accessions. Other than total catechins, the trihydroxylated catechins showed a high loading value in differentiating the accessions. The genetic control of the ratio of dihydroxylated and trihydroxylated catechins is found to be based on a correlation with AFLP markers. The genetic similarity between Kangra Asha and Kangra Jat suggests that Kangra Jat must be descended from Kangra Asha. Kangra Jat is well adapted to local environmental conditions, as is evident from its high catechin content.


Asunto(s)
Camellia sinensis/genética , Variación Genética , Catequina/genética , ADN de Plantas/genética , Geografía , India , Hojas de la Planta/genética
20.
J Agric Food Chem ; 51(16): 4764-8, 2003 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-14705910

RESUMEN

Green tea manufacture was standardized with respect to the inactivation of polyphenol oxidase (PPO), rolling, and drying for quality manufacture. Inactivation of PPO by parching, steaming, microwave heating, and oven heating was monitored in tea shoots. The inactivated shoots were rolled under regimens of high and low pressures and dried by microwave heating, oven heating, or sun-drying; total phenols and catechins were estimated. Parched and sun-dried teas contained the lowest levels of total phenols and catechins, and their infusions were dull in color with a slightly burnt odor. Microwave-inactivated and-dried teas showed the highest levels of total phenols and catechins, and their infusions were bright in color and sweet in taste with a subtle pleasant odor. In steam-inactivated and oven/microwave-dried teas, total phenol and catechin contents were intermediate between parched and sun-dried teas and microwave-inactivated and microwave-dried teas, and their infusions were bright with a umami taste.


Asunto(s)
Manipulación de Alimentos/métodos , Microondas , , Catequina/análisis , Color , Humanos , Odorantes , Fenoles/análisis , Gusto , Té/química
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