• Journal of the Korean Magnetic Resonance Society
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• v.12 no.1
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• pp.1-13
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• 2008

Acetyl-CoA carboxylase (ACC) catalyzes the first step in fatty acid biosynthesis: the synthesis of malonyl-CoA from acetyl-CoA. As essential regulators of fatty acid biosynthesis and metabolism, ACCs are regarded as therapeutic targets for the treatment of metabolic diseases such as obesity, In ACC, the biotinoyl domain performs a critical function by transferring an activated carboxyl group from the biotin carboxylase domain to the carboxyl transferase domain, followed by carboxyl transfer to malonyl-CoA. Despite the intensive research on this enzyme, only the bacterial and yeast ACC structures are currently available, To explore the mechanism of ACC holoenzyme function, we determined the structure of the biotinoyl domain of human ACC2 and analyze its characteristics using NMR spectroscopy. The 3D structure of the hACC2 biotinoyl domain has a similar folding topology to the previously determined domains from E. coli and P. Shermanii, however, the 'thumb' structure is absent in the hACC2 biotinoyl domain. Observations of the NMR signals upon the biotinylation indicate that the biotin group of hACC2 does not affect the structure of the biotinoyl domain, while the biotin group for E. coli ACC interacts directly with the thumb residues that are not present in the hACC2 structure. These results imply that, in the E. coli ACC reaction, the biotin moiety carrying the carboxyl group from BC to CT can pause at the thumb of the BCCP domain. The human biotinoyl domain, however, lacks the thumb structure and does not have additional non-covalent interactions with the biotin moiety; thus, the flexible motion of the biotinylated lysine residue must underlie the "swinging arm" motion. This study provides insight into the mechanism of ACC holoenzyme function and supports the "swinging arm" model in human ACCs.

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.419-426
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• 2019

Background: This study aimed to identify antioxidant compounds from the seeds of Dolichos lablab L. by bioassay-guided isolation and recrystallization. Methods and Results: The water layer of D. lablab L. seed extract inhibits intracellular reactive oxygen species (ROS) expressing the 2',7'-dichlorofluorescein diacetate (DCF-DA), Cu/Zn superoxide dismutase (SOD) and catalase genes, as determined by quantitative real-time PCR (qRT-PCR). Two compounds were purified from the water layer of the seeds of D. lablab L. using column chromatography and prep-high performance liquid chromatography (HPLC). Using nuclear magnetic resonance (NMR) and electrospray Ionization mass spectrometry (ESI-MS), their chemical structures were identified as 5-[(2-acetyl-2,3-dihydro-1H-indazol-1-yl)carbonyl]-4,5-dihydro-3H-furan-2-one (C₁₄H₁₄N₂O₄) and stachyose. Conclusions: Two active antioxidant compounds were purified from the seed extract of D. lablab L. seed extract and the structures of these compounds were identified as C₁₄H₁₄O₄N₂ and stachyose.

• Molecules and Cells
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• v.24 no.3
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• pp.437-440
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• 2007

$OGL-20P^T$-358 is a novel 66 amino acid residue protein from the hyperthermophile Thermococcus thioreducens sp. nov., strain $OGL-20P^T$, which was collected from the wall of the hydrothermal black smoker in the Rainbow Vent along the mid-Atlantic ridge. This protein, which has no detectable sequence homology with proteins or domains of known function, has a calculated pI of 4.76 and a molecular mass of 8.2 kDa. We report here the backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignments of $OGL-20P^T$-358. Assignments are 97.5% (316/324) complete. Chemical shift index was used to determine the secondary structure of the protein, which appears to consist of primarily ${\alpha}$-helical regions. This work is the foundation for future studies to determine the three-dimensional solution structure of the protein.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.267-271
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• 2000

Abstract Two glucans (PONGa and PONGb) differing in their anomeric and glycosidic linkage structures were isolated from the water-insoluble materials (PON) of Pleurotus ostreatus basidiocarps, which activated the complement system and were almost soley composed of D-glucose. The isolatIon was achieved by repeated precipitations with ethanol and adsorption on concanavalin A (Con A) of paN suspension in thymol/NaCL Based on methylation analysis. IR, GLC-MS, $^1H,{\;}and{\;}^{13}C-NMR$ spectroscopies, PONGa was found to be a branched a-glucan composed of ${\alpha}-linked$ D-glucopyranose residues and ${\alpha}-linked$ units with 6-branching points, whereas PONGb was a linear ${\beta}-1,3-glucan$ composed mainly of ${\beta}-1,3-linked$ D-glucopyranose residues. The PONGb particles reacted more potently than the PONGa particles as C3 activator in alternative complement hemolysis and crossed-immunoelectrophoresis using anti-human C3, thereby suggesting that the complement activating components of PON were ${\beta}-(13)-glucans rather$ than ${\alpha}-glucan$ components.onents.

• 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.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1035-1038
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• 2009

Phytochemical investigation of the methanolic extract of Diospyros kaki leaves led to the isolation of osmanthuside H (1) and a new phenol glycoside, named gamnamoside [4-(3-hydroxypropyl)-2-methoxyphenol $\beta$-D-apiofuranosyl( 1 $\rightarrow$ 6)$\beta$-D-glucopyranoside] (2) along with (-) catechin (3) through a series of reversed phase column chromatography and preparative C18 HPLC. The structures of the isolates were determined by spectroscopic methods including IR, UV, HRTOFMS, and 2D NMR. Compounds 1, 2, and 3, showed good inhibitory activities ($IC_{50}$) of 175.4, 94.4, and 126.6 ${\mu}g/mL$ respectively, whereas a reversible ADH inhibitor, 4-methylpyrazole, showed the $IC_{50}$ of 326.6 ${\mu}g/mL$ against alcohol dehydrogenase (ADH).

• Journal of Applied Biological Chemistry
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• v.53 no.2
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• pp.77-81
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• 2010

The seed of cowpea (Vigna sinensis K.) was extracted with 80% aqueous methanol (MeOH). And the concentrated extract was partitioned with ethyl acetate (EtOAc), n-butanol (n-BuOH) and $H_2O$, successively. The repeated silica gel and octadecyl silica gel (ODS) column chromatographic separations for the EtOAc and n-BuOH fractions led to isolation of four sterols. And the chemical structures of the compounds were determined as a mixture of stigmasterol and $\beta$-sitosterol with the ratio of 4 to 3 (1), 7-ketositosterol (2), and stigmasterol 3-O-$\beta$D-glucopyranoside (3) from the interpretation of spectroscopic data including nuclear magnetic resonance (NMR) spectrum metric, mass (MS) spectrum metric and infrared (IR) spectroscope. This study reports the first isolation of $\beta$-sitosterol, 7-ketositosterol, and stigmasterol 3-O-$\beta$-D-glucopyranoside from the seed of Vigna sinensis K. In addition, compound 2, 7-ketositosterol, is rarely occurred in natural source including plant.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.237-248
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• 2006

Forty one compounds such as ester, sulfonyl ester, carbamate, ether and phosphoyl ester derivatives of thymol(I) and carvacrol(II) were synthesized. These derivatives were identified by IR, GC/MS and $^1H$-NMR spectra. Their antifungal activities were tested against various plant pathogenicfugi. Among them, several compounds were showed potent in vivo antifungal activities. The selected compounds showing in vitro antifungal activities were tested in vivo antifungal activities aganint 5 plant diseases such as rice blast, rice sheath blight, tomato late blight, cucumber anthracnose, and cucumber gray mold. As a result, 2-isopropyl-5-methylphenylacetate(I-1a) effectively suppressed the development cucumber gray mold and rice blast. Methyl(2-isopropyl-5-methylphenoxy)acetate(I-6d) and ethyl 4-(5-methyl-2-isopopylphenoxy)crotonate(I-7d) also showed potent in vivo antifungal actively againt rice sheath blight and tomato late blight, respectively.

• Korean Journal of Pharmacognosy
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• v.51 no.1
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• pp.36-40
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• 2020

The CHCl₃ fraction of the MeOH extract of Ganoderma gibbosum (Ganodermataceae) exhibited cytotoxic activity on five cancer cell lines (MDA-MB-231, SK-hep1, A549, HCT116, and SNU638). Six highly oxygenated lanostane-type triterpenoids (lanostanoids) were isolated by column chromatography to test cytotoxicity on cancer cells. The five known lanostanoids were identified as gibbosic acids A, B, D, G, and H by comparison of molecular ion peaks with the literature data. The structure of a new lanostanoid, gibbosic acids I, was identified to be 3β,8β,15β,20S-tetrahydroxy-7,12,23-trioxolanost-9(11)-en-26-oic acid on the basis of NMR and MS spectroscopy. The three lanostanoids of gibbosic acids A, H, and I of the six isolates significantly suppressed the growth of cancer cells. In particular, the IC₅₀ of gibbosic acid H was prominently low ranging from 2.64-6.56 μM.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2342-2348
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• 2014

Poly(lactic-co-glycolic acid) (PLGA) were grafted to both ends of Pluronic$^{(R)}$ F68 ($(EO)_{75}(PO)_{30}(EO)_{75}$) triblock copolymer to produce poly{(lactic acid)$_m$-co-(glycolic acid)$_n$}-b-poly(ethylene oxide)$_{75}$-b-poly(propylene oxide)$_{30}$-b-poly(ethylene oxide)$_{75}$-b-poly{(lactic acid)$_m$-co-(glycolic acid)$_n$} (PLGA-F68-PLGA) pentablock copolymers. Molecular weights of PLGA blocks were controlled and five kinds of pentablock copolymers with different PLGA block lengths were synthesized using in-situ ring-opening polymerization of D,L-lactide and glycolide with tin(II) 2-ethylhexanoate ($Sn(Oct)_2$) catalyst. PLGA-F68-PLGA pentablock copolymers were characterized by $^1H$- and $^{13}C$-NMR, GPC, and TGA. The numbers (2m, 2n) of repeating units for lactic acid and glycolic acid inside PLGA segments were obtained as (48, 17), (90, 23), (125, 40), (180, 59), and (246, 64), with $^1H$-NMR measurement. From NMR data, the resultant molecular weights were determined in the range of 12,700-29,700, which were similar to those obtained from GPC. Polydispersity index was increased in the range of 1.32-1.91 as the content of PLGA blocks increased. TG and DTG thermograms showed discrete degradation traces for PLGA and F68 blocks, which indicate the weight fractions of PLGA blocks in pentablock copolymers can be calculated by TG profile and it is possible to remove PLGA block selectively. Hydrodynamic radius and radius of gyration of pentablock copolymer micelle were obtained in the range of 46-68 nm and 31-49 nm, respectively, in very dilute (i.e. 0.005 wt %) aqueous solution of THF:$H_2O$ = 10:90 by volume at $25^{\circ}C$.