• Korean Journal of Pharmacognosy
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• v.7 no.1
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• pp.3-13
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• 1976

The hitherto existing gap in the field of chromatographic methods has been filled by the direct coupling of a suitable oven (TAS-oven) with TLC. The sample to be examined is heated either isothermally or linearly within the temperature gradient of $50{\sim}450^{\circ}C$. The volatile and/or thermolytically evolved substances are fractionated on the TLC-layer and subsequently chromatographed under standard conditions. Transport mechanisms from the sample to the TLC-layer, applications of the TAS-procedure and further developments are discussed. Thermofractography, developed from the TAS-procedure, is demonstrated on different groups of natural substances such as alkaloids, amino acids, nucleic acids. nucleosides, nucleotides, triglycerides and other lipids, pyrone glycosides and aglycon. Experimental work and results on the thermolysis of macromolecular natural and synthetic substances, natural polyphenols, tanning agents and leather and the possibilities of differentiating various lignins, carbohydrate and synthetic polymers are reported. Further, it is shown that classical reactions in the microgram range, e.g. zinc dust distillation, sulphur-and selenium dehydrogenation and catalytic dehydrogenation, can be coupled directly with TLC. Also described is a method which allows to investigate the gaseous compounds evolved during thermofractography in the range of up to $450^{\circ}C$. Thermal procedures coupled with TLC open up the following new possibilities for chemical microanalysis: fractionated separation of distillable and sublimable components, fractionated thermolysis and carrying out of thermal reactions in the ultra micro range.

• Natural Product Sciences
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• v.17 no.3
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• pp.175-180
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• 2011

Eleven compounds were isolated from fresh leaves of Abies koreana (Pinaceae), and structures of these compounds were determined to be 3-hydroxy-2-methyl-4-pyrone (1), maltol-3-O-${\beta}$-D-glucoside (2), (-)-epicatechin (3), naringenin 7-O-${\beta}$-D-glucopyranoside (4), naringenin-7-O-rhamnoglucoside (5), kaempferol 3-O-${\beta}$-D-glucopyranoside (6), (+)-isolariciresinol (7), secoisolariciresinol (8), rhododendrol (9), ferulic acid (10) and 4-(4-hydroxyphenyl)butan-2-one (rheosmin) (11) by comparing $^1H$-, $^{13}C$-NMR and MS spectroscopic data with reference values. Compounds 3, 5, 7, 8, 9, 10, 11 were isolated for the first time from A. koreana. Among eleven isolates, compounds 1, 7 and 11 showed inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglia in a concentration dependent manner.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.320-327
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• 1999

The flavonoids are one of the most numberous and widespread groups of natural consituents. The low molecular weight of benzo-${\gamma}$-pyrone derivative are ubiquitous in plants and are vegetables nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds ubiquitous in plants containing a number of phenolic hydroxyl groups attached to ring structures conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vasclar disease indicating that oxidation may be important in the pathogenesis of human athero-sclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. How-ever hydroxylation of the flavone uncleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process the leading cause of death and disability in industrialized societies.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.184-191
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• 2003

New pyranone derivative, 2-((3E)-4(2H, 3H, -benzo[3, 4-d] 1, 3-dioxolan-5-yl)-2-oxo-but-3-enyloxy)-5-hydroxy-4H-pyran-4-one (Seletinoid $G^{TM}$), was designed as a novel retinoid on the assumption that the pyranone ring may mimic the carboxylic acid moiety in retinoid structure. The enolic hydroxy of pyranone at five position was easily deprotonated to form an enolate. The role of enolate was similar to that of carboxylic acid. To evaluate the value of Seletinoid G as an anti-aging ingredient, various tests were performed for example inhibitory effect for MMP-l expression, anti-oxidative activity, procollagen synthesis in hairless mouse and primary skin irritation. The result of this study suggested that our new synthetic retinoid could be used as a safe material for anti-aging cosmetics.

• Journal of Integrative Natural Science
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• v.7 no.3
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• pp.149-158
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• 2014

The crystal structure of the title compounds with both coumarin and sulfonamide moieties were examined. These two groups have very special for their pharmaceutical and medicinal properties have been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=$8.5775(4){{\AA}$, b=$24.9943(13){\AA}$ and c=$13.7319(7){\AA}$ [alpha & gamma=$90^{\circ}$ beta=$103.558(2)^{\circ}$]. In the structure The S1 atom shows a distorted tetrahedral geometry, with O1-S1-O2 [$121.08(1)^{\circ}$] and N1-S1-C5 [$105.85(1)^{\circ}$] angles deviating from ideal tetrahedral values are attributed to the Thrope-Ingold effect. The sum of bond angles around N1 ($354.9^{\circ}$) indicates that N1 is in $sp^2$ hybridization. The Pyridine ring adopts boat conformation and pyran rings adopt a sofa conformation. Crystal structure is stabilized by C-H...O intra molecular hydrogen bond interactions.

• Journal of Preventive Medicine and Public Health
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• v.26 no.4 s.44
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• pp.551-564
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• 1993

Since the widespread application of hyperbaric oxygenation in clinical medicine, the problems of oxygen toxicity have been attracting a deep interest from the researchers on hyperbaric medicine as a practical issue. Among extensive research trials, the study on the protective agents oxygen toxicity occupied one of the most challenging field. As the mechanisms of oxygen toxicity, the role of the oxygen free radicals produced by peroxidation process are strongly accepted by the leading researchers on oxygen toxicity, the probable protective effects of antioxidant against oxygen toxicity are sustaining a sufficient rational. Maltol ($2-methyl-3-hydroxy-{\gamma}-pyrone$) which is known to be a component of Korean red ginseng has been reporting to have an antioxidant action. But, further study is needed to provide definite evidence for this compound to be an antioxidant, since the action was based on the results which were obtained under in vitro experiment. In this study, the author attempted to evaluate the effect of maltol as protective agent against oxygen toxicity through the observation of death rate, convulsion rate, time to convulsion and microscopic pathological changes in some organs of experimental rats exposed to various conditions. The findings observed are as follows : 1) The death rate, convulsion rate, time to convulsion, lung/weight ratio and microscopic pathological finding of lung were identified as reliable objective and quantitative indices for oxygen toxicity. 2) Maltol showed excellent protective effect against pulmonary oxygen toxicity as an antioxidant.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.172-178
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• 1982

A psoralen-DNA monoadduct analogue, 4',5'-dihydropsoralen (DHP) is synthesized and its photophysical properties such as fluorescence quantum yield (0.08), phosphorescence quantum yield (0.013), fluorescence lifetime (0.95ns), and phosphorescence lifetime(0.039s) were measured in ether solution and in frozen matrix state at 77K. The photocycloaddition reaction of DHP with tetramethylethylene(TME) was carried out in solution and in the frozen state. The major photoadduct was isolated and characterized by elemental analysis and physical methods such as UV, IR, NMR, and mass spectrometry. The major DHP-TME photoadduct was proved to be an 1 : 1 $C_4$-cycloadduct formed through 2 + 2 cycloaddition of the pyrone double bond of DHP to TME.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.5
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• pp.373-377
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• 1990

Volatile components of whole sardine sauce which was prepared with $7\%$ of complex enzyme-2000($2.18{\cdot}10^4\;U/g solid$), mixed with $6\%$ of invert sugar and heated at $90^{\circ}C$ for 2 hours were compared with those of without invert sugar. Thirty seven kinds were identified from the whole volatile components of hydrolysate heated without invert sugar and fourty three kinds were identified from the hydrolysate heated with $6\%$ of invert sugar. Amines were not detected from the whole volatile components of the chopped whole sardine hydrolysate. Considerable amount of 2,3-dihydrobenzofuran and 2-acetylpyrrole, a little amount of 2,5-hydrofuran, 2-ethylbutanol, 2-pyrone, 2-acetylfuran, 2,6-dimethylpyrazine, 2-acetylpyrazine, 5-methyl-2-furfural, furfuryl acetate, butylpyrrole and 2-methyl-3-hydroxypyrone were detected in the hydrolysate thermally treated with $6\%$ of invert sugar while these were not found in the hydrolysate heated without invert sugar. But the amount of 2-methyt-1-propa-not, hexane, butyl acetate and butyl alcohol were decreased, and acetic acid and butanoic acid were detected as volatile fatty acids.

• Journal of Integrative Natural Science
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• v.7 no.2
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• pp.92-102
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• 2014

The crystal structure of the title compounds with both coumarin and sulfonamide moieties were examined. These two groups have very special for their pharmaceutical and medicinal properties have been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group C2/c with unit cell dimension a = 28.633(3) ${\AA}$, b= 9.3215(7) ${\AA}$ and c= 24.590(2) ${\AA}$ [alpha & gamma=$90^{\circ}$ beta= $115.976(3)^{\circ}$]. In the structure The S1 atom shows a distorted tetrahedral geometry, with O1-S1-O2 [119.74 $(2)^{\circ}$] and N1-S1-C5 [$105.57(1)^{\circ}$] angles deviating from ideal tetrahedral values are attributed to the Thrope-Ingold effect. The sum of bond angles around N1 ($316.2(1)^{\circ}$) indicates that N1 is in sp2 hybridization. The Pyridine ring adopts boat conformation and pyran rings adopt a sofa conformation. The carboxylate group of atoms were disordered over two positions with site occupancy factors 0.598 (9):0.402 (9). Crystal structure and packing is stabilized by $C-H{\ldots}O$ intra and inter molecular hydrogen bond interactions.

• Mycobiology
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• v.49 no.5
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• pp.491-497
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• 2021

An endolichenic fungus Xylaria grammica EL000614 produces grammicin, a potent nematicidal pyrone derivative that can serve as a new control option for root-knot nematodes. We optimized an Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for X. grammica to support genetic studies. Transformants were successfully generated after co-cultivation of homogenized young mycelia of X. grammica with A. tumefaciens strain AGL-1 carrying a binary vector that contains the bacterial hygromycin B phosphotransferase (hph) gene and the eGFP gene in T-DNA. The resulting transformants were mitotically stable, and PCR analysis showed the integratin of both genes in the genome of transformants. Expression of eGFP was confirmed via fluorescence microscopy. Southern analysis showed that 131 (78.9%) out of 166 transformants contained a single T-DNA insertion. Crucial factors for producing predominantly single T-DNA transformants include 48 h of co-cultivation, pretreatment of A. tumefaciens cells with acetosyringone before co-cultivation, and using freshly prepared mycelia. The established ATMT protocol offers an efficient tool for random insertional mutagenesis and gene transfer in studying the biology and ecology of X. grammica.