Extraction leaf extracts

Birch leaf extract Birch reduction Birch-type reactions Bird feathers Bird repellents Bireactive dyes Birkeland-Eyde process Birnessite [1244-32-5] b-Bisabolene [495-61-4]... 

Essentia.1 Oils. Essential oils (qv) are extracted from the flower, leaf, bark, fmit peel, or root of a plant to produce flavors such as mint, lemon, orange, clove, cinnamon, and ginger. These volatile oils are removed from plants either via steam distillation, or using the cold press method, which avoids heat degradation. Additional processing is sometimes employed to remove the unwanted elements from the oils, such as the terpenes in citms oils which are vulnerable to oxidation (49,50). 

Whole leaf protein concentrate, 16.5% nitrogen-free extract and 7.9% soluble soHds. 

Violet Leaf. Violet leaf absolute is produced by the usual extraction methods from Viola odorata (var. Victoria). It is grown mainly ia the south of France and Egypt. Although this material is not produced ia large amounts, it is quite valuable ia perfumery for its powerhil green leafy and doral character, an odor that belongs to many doral bouquets. The principal odorant ia violet leaf absolute is 2-/n j -6-i7j -nonadienal [55748-2]. 

A pilot plant ia India has been estabUshed to extract fiber, pulp, and juice from the leaves of sisal plants. The fiber is sold direcdy or used to manufacture rope, the cmshed pulp is used ia paper processiag, and the juice is an excellent source of hecogenin. During a three- to five-day fermentation of the juice, partial enzymatic hydrolysis causes hecogenin to precipitate as the hemisaponin ia the form of a fine sludge. This sediment is hydrolyzed with aqueous hydrochloric acid, neutralized, and filtered. This filter cake is washed with water and extracted with alcohol. The yield of hecogenin varies between 0.05 and 0.1% by the weight of the leaf (126). 

Instant tea is manufactured in the United States, Japan, Kenya, Chile, Sri Lanka, India, and China. Production and consumption in the United States is greater than in the rest of the world. World production capacity of instant teas depends on market demand but is in the range of 8,000 to 11,000 t/yr (3). The basic process for manufacture of instant tea as a soluble powder from dry tea leaf includes extraction, concentration, and drying. In practice, the process is considerably more compHcated because of the need to preserve the volatile aroma fraction, and produce a product which provides color yet is soluble in cold water, all of which are attributes important to iced tea products (88). 

Extraction. Traditionally tea leaf is extracted with hot water either in columns or ketdes (88,89), although continuous Hquid soHd-type extractors have also been employed. To maintain a relatively low water-to-leaf ratio and achieve full extraction (35—45%), a countercurrent system is commonly used. The volatile aroma components are vacuum-stripped from the extract (90) or steam-distilled from the leaf before extraction (91). The diluted aroma (volatile constituents) is typically concentrated by distillation and retained for davoring products. Technology has been developed to employ enzymatic treatments prior to extraction to increase the yield of soHds (92) and induce cold water solubiUty (93,94). 

Other Methods. Instant tea may also be prepared by directiy extracting fermented leaf before the firing stage. These processes, only suited for practice in the tea-growing countries, have been carried out on a small scale in Sri Lanka, India, and Kenya (101). 

Astringents are designed to dry the skin, denature skin proteins, and tighten or reduce the size of pore openings on the skin surface. These products can have antimicrobial effects and are frequendy buffered to lower the pH of skin. They are perfumed, hydro-alcohoHc solutions of weak acids, such as tannic acid or potassium alum, and various plant extracts, such as bitch leaf extract. The alcohol is not only a suitable solvent but also helps remove excess sebum and soil from the skin. After-shave lotions generally function as astringents. 

The best source of the alkaloids is commercial nicotine or the concentrated tobacco extracts, used as horticultural insecticides. The average alkaloidal content of tobacco leaf is about 4,- and does not as a rule exceed 6, per cent. In 1,026 parts of the total alkaloids of Kentucky tobacco, Pictet and Rotschy found nicoteine 20, nicotimine 5 and nicotelline 1, the rest being nicotine, but, as Markwood has pointed out. 

Tabak, m. tobacco, -asche, /. tobacco ashes, auszug, m. tobacco extract, -bau, m. tobacco cultivation, -beize, /. sauce (for tobacco). -blatt, n. tobacco leaf, tabakbraun, a. tobacco-brown. 

Kuwabara and Wassink (1966) extracted 15 kg of the mycelium of Omphalia flavida (a Puerto Rican coffee-leaf fungus), and isolated a luciferin in a crystalline form. The luciferin was chemiluminescent with H2O2, and produced light using Airth s luciferase (A.max 524 nm). No information was reported concerning the chemical nature of this luciferin. 

To date, 152 species of flowering plants belonging to 46 different families, as well as a few species of mushrooms, mosses, ferns, and lichens, have been screened. Extracts from 20 seed plants have shown enough inhibitory activity to warrant further study. Leaf extracts of members of three families, Liliaceae, Pinaceae, and Labiateae, show a high incidence of antiviral agents. Several members of the Capri-foliaceae, on the other hand, contain virus-stimulating agents. 

Figure 1. Effect of twinberry leaf extract infiltrated 24 hours after virus inoculation on TMV starch lesion development on cucumber cotyledons...

Abscisin II is a plant hormone which accelerates (in interaction with other factors) the abscission of young fruit of cotton. It can accelerate leaf senescence and abscission, inhibit flowering, and induce dormancy. It has no activity as an auxin or a gibberellin but counteracts the action of these hormones. Abscisin II was isolated from the acid fraction of an acetone extract by chromatographic procedures guided by an abscission bioassay. Its structure was determined from elemental analysis, mass spectrum, and infrared, ultraviolet, and nuclear magnetic resonance spectra. Comparisons of these with relevant spectra of isophorone and sorbic acid derivatives confirmed that abscisin II is 3-methyl-5-(1-hydroxy-4-oxo-2, 6, 6-trimethyl-2-cyclohexen-l-yl)-c s, trans-2, 4-pen-tadienoic acid. This carbon skeleton is shown to be unique among the known sesquiterpenes. 

Leaves of Eucalyptus rostrata were shown to contain substances that inhibited growth and germination (90). Four active fractions were obtained from the crude leaf extract. Inhibitory constituents were shown to contain a carbonyl group and a carbon-carbon double... 

An extract from the soluble stromal proteins of purified and intact spinach-leaf chloroplasts was prepared by lysis of the cells in buffer, centrifugation of the suspension of broken cells, and concentration of the supernatant with removal of insoluble material. This extract contained all of the enzymes involved in the condensation of the cyclic moieties of thiamine, thiazole, and pyramine. Thus, the synthesis of thiamine in this extract following the addition of pyramine and putative precursors was a proof that the system had the possibility of building the thiazole. It was found that L-tyrosine was the donor of the C-2 carbon atom of thiazole, as in E. coli. Also, as in E. coli cells, addition of 1 -deoxy-D-f/irco-pen-tulose permitted synthesis of the thiamine structure. The relevant enzymes were localized by gel filtration in a fraction covering the 50- to 350-kDa molecular-mass range. This fraction was able to catalyze the formation of the thiazole moiety of thiamine from 0.1 -mM 1-deoxy-D-t/ireo-pentulose at the rate of 220 pmol per mg of protein per hour, in the presence of ATP and Mg2+. 

Detection and result The chromatogram was dried in a stream of warm air. Blood-red fluorescent chlorophyll zones were visible in the region of the solvent front. In the case of Orthosiphon leaf extract there was an intense pale blue fluorescent sinensetin zone OiRf 90-95) immediately below this, followed by a series of usually weaker blue fluorescent zones extending right down to the start zone (Fig. lA). 

NBP reagent la 90, 359 Neatan perservation la 134 Neoamygdalline lb 121 Neo-kestose lb 423 Neomycin la 287,423 Neostigmine lb 290 Nephopam la 45 Nerol la 76,327 -, glucoside la 327 Netilmicin la 105,286,287 Nettle leaf extract lb 217 Neuroleptics lb 352 Nickel-DMSO complex lb 259 Nickel cations la 144,145,311 lb 259-260... 

Organotin compounds la 399 lb 21, 319 Ornithine la 235 Orthosipon leaf extract lb 216,217 Oryzalin lb 110-112 Ovalbumin lb 401 Over pressure layer chromatography (OPLC) lb4 Oxacillin lb 84,188,301 Oxaflozan lb 268,358 Oxalic acid la 45,171,426 Oxamyl lb 332... 

Takahashi, K., Nagahama, S., Nakasbima, T. and Suenaga, H. 2003. Chemotaxonomy on the leaf constituents of Thujopsis dolabrata Sieb. et Zucc.—analysis of acidic extracts. Biochem. Syst. Ecol. 31 723-738. 

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