Biological organophosphorus acids

Selective Bond Formation of Organophosphorus Acids with Functional Groups of Biological Importance... 

Parsa, R., Green, H. (2001). Destruction of DFP by organophosphorus acid anhydrase covalently coupled to the comified layer of human epidermis. In Proceedings of the Internal Symposium on Applications of Enzymes in Chemical and Biological Defense. Orlando, FL. 

Broomfield, C. A. (1993). A purified recombinant organophosphorus acid anhydrase protects mice against soman. Chemico-Biological Interactions, 87, 279-284. 

The reagent sequence is specific for endosulfan and phosphamidon. Other insecticides, e.g. organochlorine insecticides, such as endrin, aldrin, dieldrin, DDT and BHC, organophosphorus insecticides, such as malathion, parathion, dimethoate, quinalphos, phorate and fenitrothion, or carbamate insecticides, such as baygon, car-baryl and carbofuran do not react. Neither is there interference from amino acids, peptides or proteins which might be extracted from the biological material together with the pesticides. 

A plefhora of methods developed for the determination of triazine compounds in water, soil, crops, biological fluids, etc., have been reported in the literature, and several excellent reviews are available for the interested reader. " More method papers are published on the determination of triazines in water than for all other sample matrices combined (water > soil > crop). The majority of the water method reports relate to the determination of parent triazine compounds plus compounds from one or more other chemical classes of pesticides (e.g., phenoxy acids, carbamates, pheny-lureas, acetanilides, acetamides, organophosphorus compounds, etc.) for generalized multi-residue screening or monitoring purposes. Addressed in other more selective... 

Diazinon (phosphorothioic acid 0,0-diethyl 0-(6-mcthyl-2-(l-mcthylcthyl)-4-pyrimidinyl) ester) is an organophosphorus compound with an anticholinesterase mode of action. It is used extensively to control hies, lice, insect pests of ornamental plants and food crops, as well as nematodes and soil insects in lawns and croplands. Diazinon degrades rapidly in the environment, with half-time persistence usually less than 14 days. But under conditions of low temperature, low moisture, high alkalinity, and lack of suitable microbial degraders, diazinon may remain biologically active in soils for 6 months or longer. 

The study of organophosphorus chemistry began more than 130 years ago. However, these substances found practical application only after World War II. At present the most widespread application for organophosphorus compounds is pest control in agriculture. Biological activity is characteristic of the following derivatives of phosphorus organic acids ... 

General catalytic hydrophosphinylation reaction of alkenes and alkynes with hypophosphorous compounds (385) to give H-phosphinic acid derivatives (386) has been described. Compounds (386) are important biologically active compounds as well as being synthetic intermediates which can be converted into a variety of other organophosphorus compounds using well-established procedures. ... 

One very promising organophosphorus compound is the abundant, phosphate rich, natural product myo-inositol(hexakisphosphoric acid), or phytic acid. Literature reports on the chemical, environmental, and biological behavior of phytic acid abound 13), Phytic acid is isolated from beans and leafy vegetables and is used as the starting... 

Malathion is an example of an organophosphorus insecticide, which works by inhibition of the enzyme acetylcholinesterase, responsible for the hydrolysis of the neurotransmitter acetylcholine. Inhibition of the enzyme allows the build-up of lethal concentrations of acetylcholine, convulsions and death. Malathion is a weak inhibitor of the enzyme and in humans is hydrolysed to the corresponding acid, which also has a low biological activity. In insects, malathion is oxidised to malaoxon which is 10 000 times more active than the parent compound. This causes an increase in levels of acetylcholine, which kills the insect (see Figure 5.10). 

Khomutov, R.M., Osipova, T.L, Zhukov, Y.N., and Gandurina, I.A., Organophosphorus analogs of biologically active substances. Part 5. Synthesis of a-aminophosphonic acids and some of their derivatives, Izv. Akad. Nauk SSSR, Ser. Khim., 2118, 1979 Bull. Acad. Sci. USSR, Div. Chem. Sci. (Engl. Transl.), 1949, 1979. 

Functionalized phosphonic and phosphinic acids and their derivatives are obviously of interest to the organophosphorus chemist, but the importance, both actual and potential, in other areas, particularly in the biological sphere, cannot be overemphasized. Prominent amongst the many important compounds are, for example,the insecticide dipterex (1) and the herbicide glyphosate (2), both synthetic compounds. Several phosphonic acid antibiotics have been isolated from Streptomyces species. (2 S)-2-Amino-4-(hydroxymethyl-phosphinoyl)butanoic acid (3), otherwise known as phosphinothricin, and a substance which also possesses herbicidal activity, is a component of the peptide y-(hydrox-ymethylphosphinoyl)-L-a-aminobutanoyl-L-alanyl-L-alanine, also present in the same organism. (1,2-Epoxypropyl)phosphonic acid, [(3-methyloxiranyl)phosphonic acid] as the (2R,3S)-diastereoisomer (4), also known as phosphonomycin, is important from the pharmaceutical standpoint as a broad spectrum bactericide, and it is produced commercially. 

The LbL technique is undoubtedly one of the best methods to incorporate biological components into man-made devices. Therefore, sensor applications must be one of the most promising subjects for LbL assemblies of biomaterials. For example, Leblanc and coworkers used several bilayers of chitosan and poly(thiophene-3-acetic acid) as cushion layers for stable enzyme films [187]. The first five bilayers of the cushion layer allowed for better adsorption of organophosphorus hydrolase than the corresponding adsorption on a quartz slide. The immobilized enzyme becomes more stable and can be used under harsher conditions. The assembled LbL films can be used for spectroscopic detection of paraoxon, an organophosphorus compound. This cushion layer strategy provides a well-defined substrate-independent interface for enzyme immobilization, in which the bioactivity of the enzyme is not compromised. This leads to fast detection of paraoxon and quick recovery times. 

Biological methods of detection have included enzyme inhibition for organophosphorus (OP) pesticides. After mobile-phase development, the layer is sprayed with esterase-1 Bacillus subtilis), followed by 1-thionaphthyl acetate substrate, and finally [2,2 -azo(l-naphthol-8-chloro-3,6-disulfonic acid) 4,4 -diphenyl disulfide] indicator to produce pink zones on a blue background with 0.05-5 ng minimum detection limits. Herbicides have been detected by inhibition of the Hill photosynthesis reaction. 

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