• YAKHAK HOEJI
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• v.43 no.1
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• pp.85-90
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• 1999

FTY720, a novel immunosuppressant, elevated the level of endogenous sphingoid bases in a dose-dependent manner within 3 hr in $LLC-PK_1$ cells. The relative molar ratio of sphingoid bases expressed as sphingosine/sphinganine (SPN/SPA), a biomarker of altered sphingolipid biosynthesis, in $10{\;}{\mu}M$ of FTY720 showed tow-fold increase as compared with the one in control culture. FTY720 under the serum-free medium condition increased only cytosolic free sphingosine concentration, not sphinganine concentration in a time-dependent manner over the 8 hr incubation under the same condition as in serum free cultures, the SPN/SPA ratio began to fluctuate and the number of floating cells as an indicator of cytotoxicity was increased 8 hr after the addition of FTY720 to cultured cells. These results suggest that the process of FTY720-induced cell death in $LLC-PK_1$ cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.177-183
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• 2002

Cerebroside fatty acids, sugars and long-chain sphingoid bases in raw soybean and soybean fermented foods (chongkukjang and deunjang) were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-pH anion exchange chromatography with pulsed amerometric detection (HPAEC-PAD). Fatty acids of acid-hydrolyzed cerebrosides were derivatized to O-TMS methylester and analysed. The major fatty acids in raw soybean and chongkukjang cerebrosides were identified as 2-hydroxyhexadecanoic acid (16 : 0h), 2-hydroxydocosanoic acid (22 : 0h) and 2-hydroxytetracosanoic acid (24 : 0h). In the case of deunjang cerebroside, 24 : 0h (40.9%) and 22 : 0h (23.4%) were major fatty acids, but 16 : 0h, 23 : 0h, 25 : 0h and 26 : 0h were also detected. Long-chain sphingoid bases of acid-hydrolyzed cerebrosides from raw soybean, chongkukjang and deunjang consisted primarily of 4-tracts, 8-tracts-sphingadienine (dihydroxy base, d18 : 2$\Delta$$^{4trans, 8trans}$) and sis-tracts isomers of 4-hydroxy-sphingenine (trihydroxy base, tl8:1$\Delta$$^{4trans or cis}$) with much less amounts of phytosphingosine (tl8: 0) and isomers of sphingenine (d18 : 1). Although deunjang is a soybean food fermented by fungi and microorganisms for a long period, 2-hydroxyoctadec-3-enoic acid (18 : 1h) and branched 9-methyl-4,8-sphingadienine known as compositional cerebroside fatty acids in Aspergillus species were not detected. Mass spectrum for sugar derivatives in cerebrosides of soybean foods including raw soybean and fermented soybean showed that C-1 of glucose moiety was linked to ceramide backbone as like a monoglucosylceramide.

• Nutrition Research and Practice
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• v.5 no.5
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• pp.396-403
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• 2011

Ceramides (Cer) comprise the major constituent of sphingolipids in the epidermis and are known to play diverse roles in the outermost layers of the skin including water retention and provision of a physical barrier. In addition, they can be hydrolyzed into free sphingoid bases such as $C_{18}$ sphingosine (SO) and $C_{18}$ sphinganine (SA) or can be further metabolized to $C_{18}$ So-1-phosphate (S1P) and $C_{18}$ Sa-1-phosphate (Sa1P) in keratinocytes. The significance of ceramide metabolites emerged from studies reporting altered levels of SO and SA in skin disorders and the role of S1P and Sa1P as signaling lipids. However, the overall metabolism of sphingoid bases and their phosphates during keratinocyte differentiation remains not fully understood. Therefore, in this study, we analyzed these Cer metabolites in the process of keratinocyte differentiation. Three distinct keratinocyte differentiation stages were prepared using 0.07 mM calcium (Ca$^{2+}$) (proliferation stage), 1.2 mM Ca$^{2+}$ (early differentiation stage) in serum-free medium, or serum-containing medium with vitamin C (50 ${\mu}L$/mL) (late differentiation stage). Serum-containing medium was also used to determine whether vitamin C increases the concentrations of sphingoid bases and their phosphates. The production of sphingoid bases and their phosphates after hydrolysis by alkaline phosphatase was determined using high-performance liquid chromatography. Compared to cells treated with 0.07 mM Ca$^{2+}$, levels of SO, SA, S1P, and SA1P were not altered after treatment with 1.2 mM Ca$^{2+}$. However, in keratinocytes cultured in serum-containing medium with vitamin C, levels of SO, SA, S1P, and SA1P were dramatically higher than those in 0.07- and l.2-mM Ca$^{2+}$-treated cells; however, compared to serum-containing medium alone, vitamin C did not significantly enhance their production. Taken together, we demonstrate that late differentiation induced by vitamin C and serum was accompanied by dramatic increases in the concentration of sphingoid bases and their phosphates, although vitamin C alone had no effect on their production.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.287.1-287.1
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• 2001

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.162.1-162.1
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• 2003

The purpose of this study was to determine the possibility of sphingolipid as a diagnostic marker for Myocardiac Infarction(MI), atherosclerosis-related cardiovascular disease. Sphingolipids are known to playa role in the occurrence of atherosclerosis in human blood vessels. Platelet-poor plasma(PPP) and washed platelets were prepared from healthy volunteers and MI patients, and sphingolipids analyzed. (omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1266-1271
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• 2001

The cytotoxic effects of lipid extracts from soybean products were studied using K562 human leukemia cell, Yac1 mouse leukemia cell and S 180 mouse sarcoma cell. Total lipids from soybean powder, soybean curd residue and doenjang were extracted with chloroform/methanol (2 : 1) and water saturated butanol, consecutively, and fractionated into acetone supernatants (AS fraction) and acetone precipitates (AP fraction) by adding excess acetone. AS fraction of doenjang lipids showed the strongest cytotoxic effects on K562, Yac1 and S180 cancer cells, whereas each lipid fraction of soybean curd residue also showed relatively weak cytotoxic effects on cancer cells but soybean powder did not. AS and AP fractions of doenjang contained more free fatty acids than those of soybean curd residue and soybean. And when lipid fractions were digested with 0.4 N KOH/methanol, doenjang lipid fractions showed to contain some alkali-stable substances which showed positive reaction with ninhydrin solution on silica TLC separation.

• Archives of Pharmacal Research
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• v.24 no.2
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• pp.144-149
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• 2001

N-acetylsphingosine (C2-ceramide) is a synthetic water-soluble ceramide mimicking the activity of natural ceramides. By fixing chiral conformation on carbon numbers 2 and 3 in the ceramide structure, four chiral C2-ceramides naming d-erythro-, I-erythro-, d-threo-and 1-three C2-ceramide were synthesized. We have investigated the chiral effects of these C2-ceramides on the sphingolipid metabolism, particularly on both the sphingolipid bio- synthetic pathway and on the degradation pathway. In both HL-60 and U937 cells, the chiral C2-ceramide ($10{\mu}\textrm{m}$) showed sphingosine accumulation monitored fluoromatrically by a high performance liquid chromatographic separation of the sphingoid bases. Most importantly, in HL-60 cells, l-erythro C2-ceramide induced a 50 fold increase in sphingosine as compared to the control, while l-threo C2-ceramide exhibited a minimal 7-fold in-crease. In contrast, sphinganine, another sphingoid base, showed less accumulation by any chiral C2-ceramide tested under the same conditions. These results suggested that chiral C2-ceramide primarilyacts on the sphingolipid degradation pathway rather than on the sphingolipid biosynthetic route. The strong $C_0/G_1$ phase arrest in the cell cycle by treatment of I-erythro C2-ceramide indicates that the blockade of the sphingolipid degradation pathway might be concomitantly involved in the dysfunction of the cell cycle. On the other hand, the fact that all chiral C2-ceramides tested failed to inhibit the activity of sphingosine kinase acting on the removal of sphingosine by producing sphingosine-1 -phosphate demonstrates that chiral C2- ceramides may increase sphingosine by activating various ceramidases by which natural ceramides are divided into sphingosine and free fatty acids. However, the precise steps involved in this interaction are still unknown.

• Analytical Science and Technology
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• v.7 no.4
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• pp.547-554
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• 1994

Ceramide components were detected from a native mushroom, "Phellinus ribis" growing in Korea. Cerebroside fractions were isolated by silica column chromatography. The ceramide fraction were purified by preparative TLC and their constituents were analyzed by using GC-MS and FAB-MS. The fatty acid components consisted of mainly hydroxy fatty acids($C_{22:0}$, $C_{25:0}$, $C_{24:0}$, $C_{23:0}$) : The major components of long-chain base were trihydroxy-bases, principally 4-hydroxy sphinganin analogues.