Flavonoids leaves

Flavonoids Leaves, stalk, buds Quercetin, hyperoside, quercitrin, isoquercitrin, 13, 118 biapigenin... 

Enzymes. The enzymes most important to the chemistry and manufacturing of tea are those responsible for the biosynthesis of tea flavonoids (Table 4) and those involved in the conversion of fresh leaf into manufactured commercial teas. 

Table 2.4 Flavonoid variation in leaf exudates of Achillea aspleniifolia (from Valant-Vetschera and Wollenweber, 1988)...

This example involves a smdy of free flavonoids (aglycones) present on the leaf surface of Mentha suaveolens Ehrh. (Lamiaceae) growing in Spain and in Algeria... 

Phlox Carolina L., a tall, perennial phlox native to southeastern United States, was shown to exhibit a substantial degree of flavonoid variation by Levy and Levin (1975). In a subsequent paper. Levy and Lujii (1978) described attempts to establish geographical patterns in the occurrence of leaf fiavonoids. Seventy-three collections were made representing populations in Georgia, Alabama (a total of 64 populations). 

Table 7.1 Flavonoid aglycones from leaf surfaces of Larrea tridentata and L. divaricata (from Mabry et al., 1977)...

Lincoln, D. E. 1980. Leaf resin flavonoids of Diplacus aurantiacus. Biochem. Syst. Ecol 8 397-400. 

Valant-Vetschera, K. M. and Wollenweber, E. 1988. Leaf flavonoids of the Achillea millefolium group. 11. Distribution patterns of free aglycones in leaf exudates. Biochem. Syst. Ecol. 16 605-614. 

Williams, C. A. and Garnock-Jones, P. J. 1986. Leaf flavonoids and other phenolic glycosides and the taxonomy and phytogeny of Fuchsia sect. Skinnera (Onagraceae). Phytochemistry 25 2547-2549. 

The initial oxidation of the flavanol components of fresh leaf to quinone structures through the mediation of tea polyphenol oxidase is the essential driving force in the production of black tea. While each of the catechins is oxidizable by this route, epigallocatechin and its galloyl ester are preferentially oxidized.68 Subsequent reactions of the flavonoid substances are largely nonenzymic. 

VOIRIN, B., BAYET, C., Developmental variations in leaf flavonoid aglycones of Mentha x piperita, Phytochemistry, 1992, 31,2299-2304. 

Selective Elution of Flavonoids from Terpenoids in Ginkgo biloba Leaf Extracts... 

The leaf flavonoids of the cruciferous species such as Camelina sativa, Crambe abyssinica, Crambe hispanica, Thlaspi arvense, Brassica napus and Sinapis alba were separated and identified with the combination of HPLC, TLC and paper chromatography. Llavonoid aglycones were extracted by cutting fresh three-week-old leaves in tiny pieces and boiled in 50 ml of 2 M HC1 for 45 min. 

J. Onyilagha, A. Bala, R. Hallett, M. Gruber, J. Soroka and N. Westcott, Leaf flavonoids of the cruciferous species, Camelina sativa, Crambe spp., Thlaspi arvense and several other genera of the family Brassicacaea. Biochem. Syst. Ecol. 31 (2003) 1309-1322. 

T.M. Upson, R.J. Grayer, J.R. Greenham, C.A. Williams, F. Al-Ghamdi and F.-H. Chen, Leaf flavonoids as systematic characters in the genera Lavandula and Sabaudia. Biochem. Syst. Ecol. 28 (2000) 991-1007. 

Manthey JA, Grohman K, Berhow MA, Usserat B (2000) Changes in citrus leaf flavonoid concentrations resulting from blight-induced zinc-defidency. Plant Physiol Biochem 38 333-343... 

Figure 6. A Photomicrograph (x 51,000) of caffeine treated leaf epidermal cell showing electron-dense deposits on cell wall and membrane vesicles fusing with the plasmalemma (arrows). B Immunofluorescence labeling of flavonoids in cell walls of leaf epidermal strips (arrows) and autofluorescent stomata (x 62.5). C Immunogold labeling of the walls of a mesophyll cell (left, x 41,000). Ch, chloroplast EC, epidermal cell G, Golgi IS, intercellular space MC, mesophyll cell (right, control x 19,500).

Analgesic activity. Ethanol (50%) extract of the entire plant, administered intraperi-toneally to mice at a dose of 250 mg/kg, was active vs tail pressure method Flavonoid fraction of the leaf, administered intraperi-toneally to mice, was active 5 The inflorescence, administered orally to male rats, produced weak activity vs paw pressure test. 

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