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]... 

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. 

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...

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... 

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... 

Competitive reduction of Au(III) and Ag(I) ions occurs simultaneously in solution during exposure to neem leaf extract leads to the preparation of bimetallic Au-core/Ag-shell nanoparticles in solution. TEM revealed that the silver nanoparticles are adsorbed onto the gold nanoparticles, forming a core/sheU structure. Panigrahi et al. [121] reported that sugar-assisted stable Au-core/Ag-shell nanoparticles with particles size of ca. 10 nm were prepared by a wet chemical method. Fructose was found to be the best suited sugar for the preparation of smallest particles. 

FIGURE 7.2 Kubelka-Munk densitogram of a spinach leaf extract taken at 305 nm. The two peaks at 16-mm and 17-mm distances are due to chlorophyll b and chlorophyll a. 

Figure 8. Radish root growth bioassay of water leachate and extract of D. illinoensis. (-) leachate (-----) leaf extract.

Phytotoxicity of Root Exudates and Leaf Extracts of Nine Plant Species... 

POPE ET AL. Phytotoxicity Root Exudates and Leaf Extracts... 

Figure 1. System for collection of root exudates and leaf extracts.

Tomato root growth bloassay of leaf extracts. Three hundred mg samples of fully expanded leaves were taken from each plant studied. Each sample was ground with a Polytron1 in 30 ml of distilled water and the extract was filtered. Five ml aliquots of each extract were pipetted onto three layers of germination paper in a 10 by 10 by 1.5 cm plastic petri dish. Distilled water was used as a control treatment. Twelve tomato seeds were placed in a 3x4 array in each dish, and incubated at 20C for 168 hours, prior to root measurement. The experimental design was a completely randomized design with five replications (dishes) per treatment except the control which had 10 replications. The experiment was repeated each week for 9 weeks. 

Soybean leaf extracts have not previously been reported to be phytotoxic however many other leguminous species have been shown to be active (1,17). The possible allelopathic activity of soybean indicated by these bloassays is potentially economically important, since soybean is a major crop world wide. 

Table VII. Tomato root growth bioassay of leaf extracts...

Leaf Extracts Nine Week Mean Root Length (mm) U... 

Table VI. Percent germination of birdsfoot trefoil and red clover seeds exposed to leaf extracts of tall fescue genotypes ...

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