Phenolic Compounds from Whole Plants

The effectiveness of phytofactors influencing bacteria specialized in ammonia production depends also on their chemical structure, which was proved by Flythe and Kagan (39). They investigated red clover Triforium pratense), rich in soluble phenols, and for direct experiments they used extracted pure phenolic compounds, such as biochanin A, and also the extract from the whole plant The anti-effect of Clostridium sticklandii, one of the bacteria from the HAP group, was observed in the case of the extract from the whole plant and biochanin A, while no effect was found for other phenolic compounds. The results of research indicate that some... 

The previous chapters have demonstrated that liquid-liquid extraction is a mass transfer unit operation involving two liquid phases, the raffinate and the extract phase, which have very small mutual solubihty. Let us assume that the raffinate phase is wastewater from a coke plant polluted with phenol. To separate the phenol from the water, there must be close contact with the extract phase, toluene in this case. Water and toluene are not mutually soluble, but toluene is a better solvent for phenol and can extract it from water. Thus, toluene and phenol together are the extract phase. If the solvent reacts with the extracted substance during the extraction, the whole process is called reactive extraction. The reaction is usually used to alter the properties of inorganic cations and anions so they can be extracted from an aqueous solution into the nonpolar organic phase. The mechanisms for these reactions involve ion pah-formation, solvation of an ionic compound, or formation of covalent metal-extractant complexes (see Chapters 3 and 4). Often formation of these new species is a slow process and, in many cases, it is not possible to use columns for this type of extraction mixer-settlers are used instead (Chapter 8). 

The objectives of the studies reported herein were to (a) compare the effects of a series of phenolic acids, coumarins, and flavonoids on whole chain electron transport and phosphorylation in Isolated plant chloroplasts and mitochondria and (b) identify specific sites of inhibition with polarographic and enzymatic techniques. Exploratory studies were conducted with the 20 compounds listed in Table I. The three glycosides are shown indented below the corresponding aglycones. Detailed studies were conducted with the six compounds, one representative member from each chemical family, designated with an asterisk. 

Herbicides may be selective, as for broad-leaved weeds in cereal crops, or unselective, essentially for land clearance. 2,4-Dichlorophenoxyacetic acid (2,4-D), 24.6, was commercialized in the 1940s it is inexpensive, is easy to make, and kills broad-leaved weeds in cereal crops. Worldwide, it is the most widely used herbicide. It is a synthetic auxin, or plant hormone, acting only on dicots and not monocots. There is a whole family of related compounds, prepared from chloroacetic acid (or other halo acids) and various chlorinated phenols. Agent Orange, used as a defoliant in Vietnam in the 1970s, was a 1 1 mixture of 2,4-D and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). The main concerns about its use relate to the possibility that dioxins are formed as contaminants in its manufacture. A few countries ban its use for control of weeds in domestic lawns. 

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