• Archives of Pharmacal Research
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• v.26 no.9
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• pp.716-718
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• 2003

In the course of our search for Acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors from natural sources, a new type of ACAT inhibitor was isolated from a methanol extract of Diospyros kaki. On the basis of spectral and structural evidence, the compound was identified as pheophorbide A-methyl ester. Pheophorbide A-methyl ester inhibited ACAT activity in a dose dependent manner with an $IC_{50}$ value of 1.85 $\mu$ g/mL.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.220-227
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• 2010

Fatty acids in seed oil from plants are essential for human nutrients and have been used for industrial purpose. The growing demands of seed oil as food resources and feedstocks for industrial uses have attempted to modify fatty acid composition and to increase oil content in transgenic plants. However, production of unusual fatty acids in transgenic plants are limited, which is not synthesized the level same as original plants. This bottleneck was common for production of several unusual fatty acids in transgenic plants and suggests that there is different for substrate preference in oil metabolic pathway enzymes between host oil plants and original wild plants. Review of acyltransferases involved in acyl-editing and seed oil accumulation of oil plant and wild-plant producing unusual fatty acids will design strategies to maximize the production of unusual fatty acids in transgenic plants. In here, we identified eleven acyltransferase genes in castor based on sequence homology, which will be useful to increase hydroxy unusual fatty acids in transgenic plants.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.112-116
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• 1997

The enzymatic properties as well as its distribution in the cerebral region and subcellular organells were investigated for the neurosteroid acyltransferase from the bovine brain, which synthesize the fatty acid esters of the neurosteroids. The cerebellum region was the highest in NSAT activity while the cerebrum was the lowest with 50% of the cerebellar activity. The NSAT was found to be mainly localized in the microsomal fraction. The optimal temperature and pH were $40^{\circ}C$ and 4.9, respectively. When $^3H-DHEA$ was utilized as substrate, the $K_m$ and $V_{max}$ was $32.6\;{\mu}M$ and 4.86 nmole/mg protein/h, respectively. Under the same condition pregnenolone$({\Delta}^5P)$ was a competitive inhibitor with $K_i=22.8\;{\mu}M$ and testosterone was a uncompetitive inhibitor with $K_i=22.8\;{\mu}M$. This may suggest that the NSAT has a different conformation in the acylation of the ${\beta}-hydroxyl$ group at C-3 and C-17.

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.265-266
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• 2008

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.600-608
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• 1993

About 1, 300 strains isolated from soil were evaluated for acyl-CoA:cholesterol acyltransferase (ACAT) inhibition activity. About 4.0% of actinomycetes and 3.6% of fungi showed greater than 50% inhibition activity, respectively. However, none of the isolated bacteria exhibited inhibition activity more than 50%. Among them, one Streptomyces sp. A-3 showed a higher ACAT inhibition activity in culture broth. Isolation of the ACAT inhibitor (AI-3) was achieved by Amberlite XAD-7 column, silica-gel column, Sephadex LH-20 gel-filtration and reverse phase HPLC.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.375.4-376
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• 2002

Acyl CoA:diacylglycerol acyltransferase (DGAT) is a key enzyme involved in triacylglycerol synthesis. Too much accumulation of triacylglycerol in certain organs and tissues of the body causes high risk conditions of fatty liver. obesity and hypertriglyceridemia. leading to serious diseases of atherosclerosis. Therefore, DGAT inhibition may be worthwhile strategy for the treatment of triglyceride metabolism disorders. such as obesity or hypertriglyceridemia. (omitted)

• Natural Product Sciences
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• v.15 no.2
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• pp.110-113
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• 2009

Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes cholesterol esterification and plays important roles in intestinal absorption of cholesterol, hepatic production of lipoproteins and accumulation of cholesteryl ester within macrophages and smooth muscle cells. In our study, eight polyacetylenes (1 - 8), were isolated from the roots of Gymnaster koraiensis, and their chemical structures were identified on the basis of spectroscopic analysis and mass. Compound 2 with the (10S)-15,16-epoxy group in skeleton strongly inhibited ACAT enzyme with $IC_{50}$ value of 35.8 ${\mu}g$/mL, meanwhile the other compounds displayed significant inhibition of ACAT enzyme with the $IC_{50}$ values from 45.5 to 55.1 ${\mu}g$/mL.

• BMB Reports
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• v.50 no.7
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• pp.367-372
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• 2017

Monoacylglycerol acyltransferase 1 (MGAT) is a microsomal enzyme that catalyzes the synthesis of diacylglycerol (DAG) and triacylglycerol (TAG). However, the subcellular localization and catalytic function domain of this enzyme is poorly understood. In this report, we identified that murine MGAT1 localizes to the endoplasmic reticulum (ER) under normal conditions, whereas MGAT1 co-localize to the lipid droplets (LD) under conditions of enriching fatty acids, contributing to TAG synthesis and LD expansion. For the enzyme activity, both the N-terminal transmembrane domain and catalytic HPHG motif are required. We also show that the transmembrane domain of MGAT1 consists of two hydrophobic regions in the N-terminus, and the consensus sequence FLXLXXXn, a putative neutral lipid-binding domain, exists in the first transmembrane domain. Finally, MGAT1 interacts with DGAT2, which serves to synergistically increase the TAG biosynthesis and LD expansion, leading to enhancement of lipid accumulation in the liver and fat.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.61-67
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• 1999

Geranyllinalool, a polyisoprenoid compound, was found to block the early biosynthetic pathway of sphingolipids in LLC-PKl cells. Sphinganine, an intermediate in sphingolipid biosynthetic pathway, was abruptly accumulated in LLC-PKl cells at $2{\;}{\mu}M$ of fumonisin B1(FB1), a specific inhibitor of sphinganine N-acyltransferase, for 24 hr. Geranyllinalool lowered the $B_1(FB_1)$, a specific inhibitor of sphinganine N-acyltransferase, for 24 hr. Geranyllinalool lowered th FB1 and $50{\;}\mu$M geranyllinalool. l-Cy-closerine, an inhibitor of serine-palmitoyl transferase, was used as a positive control to evaluate the inhibitory effect of geranyllinalool. These results suggest that geranyllinalool may inhibit the serine-palmitoyl transferase, the first enzyme in de novo sphingolipid biosynthesis, resulting in the altered regulation of sphingolipid metabolism.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.267.1-267.1
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• 2003

Diacylglycerol acyltransferase (DGAT) is a microsomal enzyme that plays a central role in the metabolism of cellular glycerolipid. Recently, the generation of DGA T-deficient mice has provided a better understanding of triglyceride synthesis and its relationship to obesity. Therefore DGAT is an attractive target for treatments of triglyceride metabolism disorders, such as obesity or hypertriglyceridemia. (omitted)