• Journal of Nutrition and Health
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• v.4 no.4
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• pp.39-46
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• 1971

Since ${\beta}-aminoethylphosphonic$ acid was discovered in the living organism, the biosynthesis and biological function of aminophosphonic acids have been extensively studied. The purpose of this project consists in the two parts: 1)the preparation of DL-1-amino-2-phenylethylphosphonic acid (Phenylalanine aminophosphonic acid) and DL-1-amino-3-methylbutyl-phosphonic acid (Isoleucine aminophosphonic acid) by the method of Chamber and Isbell. 2) the study of metabolism and biological functions of those synthetic materials by the animal experiment (white rats) The importance of this project proved to be the first experience fed by animals for the elucidation of biochemical and metabolic functions in the animal body. The following organic synthesis of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid are studied. 1)Synthesis of DL-1-amino-3-methylbutylphosphonic acid a) Synthesis of Iso-butylbromide b) Synthesis of Ethyl iso-butylmalonate c) Synthesis of Iso-caproic acid d) Synthesis of $Ethyl-{\alpha}-bromo$ iso-caproate e) Synthesis of $Triethyl-{\alpha}-phosphono$ iso-caproate f) Synthesis of DL-1-amino-3-methylbutylphosphonic acid 2)Synthesis of DL-1-amino-2-phenylethylphosphonic acid a) Synthesis of Diethyl phosphite b) Synthesis of Ethylchloro acetate c) Synthesis of Triethyl phospho acetate d) Synthesis of Triethyl benzyl phospho acetate e) Synthesis of DL-1-amino-2-phenylethylphosphonic acid The synthetic compounds; DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenyl ethylphosphonic acid which are essential amino acid (isoleucine, phenylalanine)analogue are supplemented to the animal diet at the level of 0.2% and 0.4% for isoleucine analogue and 0.35% and 0.7% for phenylalanine analogue. The plain isoleucine and phenylalanine at the same level in the diet are fercilitated as comparable groups in this study. Two sets of experience including 100 male rats were carried out for seven weeks each total 14 weeks. During this period, urine samples, and each big organs were collected for the analysis of total nitrogen, phosphorus, and glycogen contents in the individual samples by Micro Kjeldahl Fisk & Subbarow and Nelson Somogye, method. 1) The result of the project a) The yield of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid showed low tendency at the level of 12.5% and 20% Melting point of those two compounds were very high and the ${\alpha}-amino$ group in the synthetic compounds showed positive reaction with ninhydrin in the violet color. b) Ail the experimental groups included in this study revealed statistically no significant difference in the organ weight, total body nitrogen retention and urinary phosphorus excretion This means isoleucine aminophosphonic acid and Phenylalanine aminophosphonic acid were utilized in the body as much as the plain amino acids, isoleucine and phenylalanine did. c) The glycogen contents in the liver of the phenylalaine aminophosphonic acid gruop showed higher statistically significant(p<0.05) in the comparision with the group of the Phenylalanine and the Standard-2. It was noteworthy that the higher glycogen content in the liver might indicate the significance in the incorporation of phenylalanine aminophosphonic acid into the intermediate of tricarboxylic acid cycle as activated state.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.261-270
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• 1992

Many herbicides that are applied at the soil before weed emergence inhibit plant growth soon after weed germination occurs. Plant growth has been known as an irreversible increase in size as a result of the processes of cell divison and cell enlargement. Herbicides can influence primary growth in which most new plant tissues emerges from meristmatic region by affecting either or both of these processes. Herbicides which have sites of action during interphase($G_1$, S, $G_2$) of cell cycle and cause a subsequent reduction in the observed frequency of mitotic figures can be classified as an inhibitor of mitotic entry. Those herbicides that affect the mitotic sequence(mitosis) by influencing the development of the spindle apparatus or by influencing new cell plate formation should be classified as causing disruption of the mitotic sequence. Sulfonylureas, imidazolinones, chloroacetamides and some others inhibit plant growth by inhibiting the entry of cell into mitosis. The carbamate herbicides asulam, carbetamide, chlorpropham and propham etc. reported to disrupt the mitotic sequence, especially affecting on spindle function, and the dinitroaniline herbicides trifluralin, nitralin, pendimethalin, dinitramine and oryzalin etc. reported to disrupt the mitotic sequence, particularly causing disappearence of microtubles from treated cells due to inhibition of polymerization process. An inhibition of cell enlargement can be made by membrane demage, metabolic changes within cells, or changes in processes necessary for cell yielding. Several herbicides such as diallate, triallate, alachlor, metolachlor and EPTC etc. reported to inhibit cell enlargement, while 2, 4-D has been known to disrupt cell enlargement. One potential danger inherent in the use of soil acting herbicides is that build-up of residues could occur from year to year. In practice, the sort of build-up that would be disastrous is unikely to occur for substances applied at the correct soil concentration. Crop injury caused by soil applied herbicides can be minimized by (1) following the guidance of safe use of herbicides, particularly correct dose at correct time in right crop, (2) by use of safeners which protect crops against injury without protecting any weed ; interactions between herbicides and safeners(antagonists) at target sites do occur probably from the following mechanisms (1) competition for binding site, (2) circumvention of the target site, and (3) compensation of target site, and another mechanism of safener action can be explained by enhancement of glutathione and glutathione related enzyme activity as shown in the protection of rice from pretilachlor injury by safener fenclorim, (3) development of herbicide resistant crops ; development of herbicide-resistant weed biotypes can be explained by either gene pool theory or selection theory which are two most accepted explanations, and on this basis it is likely to develop herbicide-resistant crops of commercial use. Carry-over problems do occur following repeated use of the same herbicide in an extended period of monocropping, and by errors in initial application which lead to accidental and irregular overdosing, and by climatic influence on rates of loss. These problems are usually related to the marked sensitivity of the particular crops to the specific herbicide residues, e.g. wheat/pronamide, barley/napropamid, sugarbeet/ chlorsulfuron, quinclorac/tomato. Relatively-short-residual product, succeeding culture of insensitive crop to specific herbicide, and greater reliance on postemergence herbicide treatments should be alternatives for farmer practices to prevent these problems.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.824-835
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• 1999

Background: Sleep-related breathing disorders are commonly found in patients with chronic renal failure and particularly, sleep apnea may have an influence on the long-term mortality rates in these patients. Maintenance hemodialysis is the mainstay of medical measures for correcting the metabolic derangements of chronic renal failure but it is uncertain whether it may alleviate sleep disorders including sleep apnea. Methods: Forty seven patients on maintenance hemodialysis were surveyed with the sleep questionnaire about their clinical symptoms related to sleep disorders. Among them, 15 patients underwent the polysomnography and their blood levels of urea nitrogen, creatinine, electrolytes and the arterial blood gases in the nights before and following hemodialysis were measured. Results: Forty(85.1%) of the 47 patients complained of the symptoms associated with sleep-wake cycle disturbances, 55.3% experienced snoring and 27.7% reported witnessed apneas. The duration of REM sleep increased significantly in the nights after hemodialysis compared to the nights without hemodialysis(p<0.05) and the percentage of total sleep time comprising NREM sleep decreased significantly in the nights following hemodialysis compared to the nights before hemodialysis(p<0.05). The percentage of total sleep time consisting of the stage 1 and 2 NREM sleep showed the trend for a decrease in the nights after hemodialysis(p=0.051), while the percentage of total sleep time comprising the stage 3 and 4 NREM sleep did not change between nights. The obstructive sleep apnea was more predominant type than the central one in both nights and there were no differences in the apnea index and the apnea-hypopnea index between the nights. The decrease in the blood level of urea nitrogen, creatinine, potassium and phosphorus was observed after hemodialysis(p<0.05), but the differences of parameters measured during polysomnography between the nights did not correlate with the changes of biochemical factors obtained on the two nights. Arterial blood gas analysis showed that pH was significantly greater in the nights after hemodialysis than in the nights before hemodialysis(p<0.05), but there were no correlations between the parameters examined during polysomnography and the parameters of arterial blood gas analysis(p<0.05). Conclusion: These results suggest that chronic renal failure is an important systemic disorder which is strongly associated with sleep disorders. Maintenance hemodialysis, although it is a widely accepted measure to treat chronic renal failure, did not significantly modulate the sleep architecture and the severity of sleep apnea. Thus, taking the patients with chronic renal failure into account, it is advisable to try not only to find a substantial way for correcting metabolic derangements but also to consider the institution of more effective treatments for sleep disorders.