• Journal of Ginseng Research
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• v.33 no.4
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• pp.311-315
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• 2009

Potassium phosphonate inhibited less mycelial growth of Phytophthora cactorum in vitro than metalaxyl-M. But the net protection rate in leaflet test and whole plant pot test was greater in potassium phosphonate than metalaxyl-M. P. ginseng appeared to have an induced resistance against P. cactorum with phosphonate around 50~100 ppm.

• Journal of the Korean Chemical Society
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• v.20 no.4
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• pp.295-298
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• 1976

The fact that a reaction between organothioenamine phosphonate and styrene oxide produces a derivative of cyclopropane has been proved by structural identification. This suggests that an anionic oxygen atom from the ring opening of the styrene oxide by nucleophilic attack of thioenamine phosphonate links to the phosphorous atom to from a betaine as an intermediate which is followed by cleavage of the weak P-C bond. The dextrorotatory optical activity of the product showed that the reaction was under the control of steric stability of the benzyl carbon in styrene which leads to the product through a sterically stable pathway.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.142-146
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• 2002

The effect of potassium phosphonate ($KH_2PO_3 or $K_2 HPO_3$) on the control of Phytophthora root rot of lettuce was evaluated in a liquid hydroponic culture. Phosphonate 100 ppm strongly inhibited mycelial growth of Phytophthora species in vitro but did not affect normal growth of lettuce in a greenhouse test. Application of the chemical before infection showed over 94% control value, while it was less than 35% when applied after infection. In a field trial, phosphonate 100 ppm, which was directly supplemented into the nutrient solution, satisfactorily controlled the disease as it did not develop until 28 days after transplanting and remained at less than 2% infection rate at the end of cultivation. Meanwhile, in the control plot, the disease initiated at 7 days after transplanting and developed rapidly reaching over 70% infection rate at 28 days. Population density of the causal pathogen, R drechsleri, in a heavily infested farm was 22.0-25.0 cfu/100 ml of nutrient solution. However, it decreased to 1.3-2.0 cfu/100 ml at 7 days after treatment with phosphonate 200 ppm.

• Research in Plant Disease
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• v.10 no.2
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• pp.142-144
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• 2004

Effect of potassium phosphonate on control of potato basal stem rot caused by Pythium myriotylum in hydroponics system was evaluated at spring and fall cultivation in Jeju island in 2001. Potassium phosphonate 200 ppm treatment, which was directly supplemented into the nutrient solution, showed 90.5%, and 100 ppm treatment showed 50.5% control value in spring cultivation. Fall cultivation, potassium phosphonate 200 ppm treatment showed 100%, and 100 ppm treatment showed 69.9% control value. Potassium phosphonate 200 ppm treatment, basal stem rot of potato started to develop 10 days ofter inoculation into the hydroponics system showed 8.0% in infection rate. Potassium phosphonate 100 ppm treatment, after 5 days showed 10.0%, and after 10 days showed 20.0% infection rate, but the non-treated was after 5 days showed 56.7%, and after 10 days showed 96.9% infection rate.

• Research in Plant Disease
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• v.9 no.3
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• pp.179-182
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• 2003

Effect of potassium phosphonate on control of potato late blight was evaluated at two fields in Jeju island. The chemical showed 82.5% control value in field located at low seacoast with 100 m elevation, while dimethomorph copper oxychloride showed 75.9 % control value. However, its control value was only 40% in another field located at mid-hilly area with 300 m elevation, in which environmental conditions of high hummudity and often rainfall were favorable to the disease development. Application intervals of the phosphonate from 7 to 15 effectively suppressed the disease and did not show statistically different control values among the spraying intervals. Results indicated that phosphonate similarly or more effectively controls potato late blight than fungicide, however, its control value could be vared according to enviromental conditions for the disease development and 15-d spraying intervals ware sufficient to suppress ther disease.

• Tribology and Lubricants
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• v.7 no.1
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• pp.40-45
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• 1991

Wear performances for dibutyl 3,5-di-t-butyl 4-hydroxy benzyl phosphonate (DBP) were invesitigated using the four ball test machine under sliding and also rolling contact conditions, and compared with ZDDP. DBP showed excellent antiwear performace compared with ZDDP under severe sliding contact. Also, DBP achieved a longer fatigue life than ZDDP under rolling contact conditions. The surface of the worn balls was observed using an optical microscope, and the wear derbis generated was measured using the Particle Quantifier (PQ).

• Archives of Pharmacal Research
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• v.23 no.3
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• pp.206-210
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• 2000

A new series of phosphonate side chain analogues of 1$\alpha$,25-dihydroxyvitamin $D_3$ (1) have been synthesized. Antiproliferative activities of theses analogues (8a,b and 9a,b) using human keratinocyte cell shows that analogues which have natural A-ring show higher activity than unnatural A-ring series and almost equally active to 1 $\alpha$,25-Dihydroxyvitamin $D_3$(1) at 1 $\mu$M level.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1678-1686
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• 2021

In this study, we prepared phosphorous flame-retarding coating solutions by mixing triphosphate (3 phosphonate), phytic acid (6 phosphonate), or ammonium polyphosphate (10 phosphonate) with boric acid as a crosslinking agent and acryl resin binder. Prepared phosphorous flame-retarding coating solutions were coated onto non-woven fabrics, respectively, to obtain high flame-retarding effects. These prepared flame-retardant non-woven fabrics were evaluated using smoke density standard test (ASTM E662), limit oxygen index standard test (ISO E622), and vertical burning standard test (UL 94). Their flame-retarding effects were affected by the number of phosphonate groups. Regardless of natural or synthetic binder resins, their effects showed the following order: ammonium polyphosphate > phytic acid > triphosphate. Natural hydrocarbon compounds were also examined to determine the possible retardancy of binder resins. Results showed that natural hydrocarbon binder resins could be used for preparing fire-retardant nonwoven fabrics.

• YAKHAK HOEJI
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• v.34 no.1
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• pp.22-33
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• 1990

Aqueous solution of bis(2,4-diaminophenyl)phosphonate(APP) was very stable, especially below pH 2.0 and the red-color compound formed by the reaction of APP and $IO_3-$ was stable at room temperature. A simple and rapid spectrophotometric method for the determination of ascorbic acid, potassium antimonyl tartrate (PAT), and isonicotinic acid hydrazide (INAH) was established by the reaction of $IO_3-$ and these reducing drugs, and the absorbance measurements were made at 500 nm. In the reaction of $IO_3-$ and each of the reducing drugs, the conditions of pH were suitable below 2.5 for ascorbic acid, below 2.0 for PAT, and below 1.5 for INAH. Beer's law did hold in the range of $17.6{\sim}1549.9\;ug$ for ascorbic acid, $33.4{\sim}2871.8{\mu}g$ for PAT,and $6.9{\sim}548.6\;{\mu}g$ for INAH. Many common ingredients present in pharmaceutical dosage forms did not interfere. The average recoveries for ascorbic acid and INAH in pharmaceutical formulations were 99.8 $-100.3\;{\pm}\;0.2{\sim}0.4%$, $99.8\;{\pm}\;0.3%$, respectively.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.65-73
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• 1999

C-P compounds(Pn; phosphonate) such as glyphosate(GPS), aminoethylphosphonate(AEPn) and methyl-phosphonate(MPn) biodegrading genes were cloned from Pseudomonas sp. strain #A1 Which assimilated GPS as sole phosphorous source. Carrying out the in vivo molecular cloning by means of Mini-Mu plasmid, the size of clones($AEPn^+$, $MPn^+$, $GPS^+$) for the gene to degrade C=P compounds are 10-19Kb, 10Kb, and 12-18 Kb, respectively. Moreover, they expressed the phenotype for each Pn when they were transformed into $\Delta phn$ mutants. Hence, it is postulated that Pseudomonas sp.#A1 has three kind of Pn degradative pathway, separately. The phn clones($AEPn^+$, $MPn^+$, $GPS^+$) are verified as the members of PHO regulon because of their phoBR-dependent characteristics.