• Bulletin of the Korean Chemical Society
• /
• v.22 no.11
• /
• pp.1236-1242
• /
• 2001

(3S,1'S)-3-(1'-Carboxy-2'-phenyl)ethylamino-2-oxetanone (1a) and (3R,1'S)-3-(1'-carboxy-2'-phenyl)ethylamino-2-oxetanone (1b) were designed, synthesized, and evaluated as inhibitors for carboxypeptidase A, a prototypical zinc protease that removes the C-terminal amino acid having an aromatic side chain from oligopeptide substrate. It was concluded from the analysis of inhibition kinetics that while 1a inactivates CPA irreversibly, its diastereoisomer, 1b is a weak competitive inhibitor for CPA. A possible explanation for the observed difference in inhibition mode that is dependent on the inhibitor stereochemistry is offered.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.4
• /
• pp.596-606
• /
• 2019

N-acyl-homoserine lactone quorum sensing (AHL-QS) has been shown to regulate many physiological behaviors in Serratia marcescens MG1. In the current study, the effects of AHL-QS on the biosynthesis of acid and neutral products by S. marcescens MG1 and its isogenic ${\Delta}swrI$ with or without supplementing exogenous N-hexanoyl-L-homoserine lactone ($C_6-HSL$) were systematically investigated. The results showed that swrI disruption resulted in rapid pH drops from 7.0 to 4.8, which could be restored to wild type by supplementing $C_6-HSL$. Furthermore, fermentation product analysis indicated that ${\Delta}swrI$ could lead to obvious accumulation for acidogenesis products such as lactic acid and succinic acid, especially excess acetic acid (2.27 g/l) produced at the early stage of fermentation, whereas solventogenesis products by ${\Delta}swrI$ appeared to noticeably decrease by an approximate 30% for acetoin during 32-48 h and by an approximate 20% for 2,3-butanediol during 24-40 h, when compared to those by wild type. Interestingly, the excess acetic acid produced could be removed in an AHL-QS-independent manner. Subsequently, quantitative real-time PCR was used to determine the mRNA expression levels of genes responsible for acidogenesis and solventogenesis and showed consistent results with those of product synthesis. Finally, by close examination of promoter regions of the analyzed genes, four putative luxI box-like motifs were found upstream of genes encoding acetyl-CoA synthase, lactate dehydrogenase, ${\alpha}$-acetolactate decarboxylase, and Lys-like regulator. The information from this study provides a novel insight into the roles played by AHL-QS in switching from acidogenesis to solventogenesis in S. marcescens MG1.

• Biomolecules & Therapeutics
• /
• v.7 no.4
• /
• pp.371-376
• /
• 1999

By cytotoxicity screening of the 65 Korean medicinal plants against leukemia L1210 and P388D$_{1}$ cell line using the MTT assay in vitro, Albizzia julibrissin was studied. This plant was extracted with MeOH and MeOH extract was solvent-fractionated with CHCl$_{3}$, EtOAc and n-BuOH in sequence. Each fraction by various solvents system was purified by column chromatography and preparative TLC, and four compounds were isolated. The structure of each compound was deduced from UV, IR, $^{1}$H-HMR, $^{13}$ C-NMR and CI-MS spectral data. The cytotoxic activity ($IC_{50}$/_ of the compounds, quercetin-3-rhamnoside, 4',5,7-trihydroxyfla-van-3-glucoside, spinasterol-3-glucoside and acacic acid lactone, were evaluated as 5 $\mu\textrm{g}$/ml, 2$\mu\textrm{g}$/ml, 1 $\mu\textrm{g}$/ml against L1210 and as 9$\mu\textrm{g}$/ml, 10$\mu\textrm{g}$/ml, 1.5 $\mu\textrm{g}$/ml, 1.5 $\mu\textrm{g}$/ml and 0.9 $\mu\textrm{g}$/ml against P388D$_{1}$, respectively.

• Korean Journal of Pharmacognosy
• /
• v.43 no.1
• /
• pp.6-9
• /
• 2012

The $CH_2Cl_2$ soluble part of the leaves of Helianthus tuberosus L. (Compositae) exhibited a potent cytotoxic activity against the cultured human tumor cell lines including A-549, SK-OV-3, SK-MEL-2, XF498 and HCT-15 in vitro. Bioassaydirected fractionation of the $CH_2Cl_2$ soluble part of this plant led to the isolation of four cytotoxic sesquiterpene lactones having ${\alpha}$-methylene-${\gamma}$-lactone ring in the molecule. On the basis of physical and spectral evidences, their structures were characterized as ${\Delta}^{4,15}$-isoatripliciolide tiglate (1), ${\Delta}^{4,15}$-isoatripliciolide methacrylate (2), budlein A isobutylate (3) and budlein A tiglate (4). The ${\Delta}^{4,15}$-isoatripliciolide tiglate (1) showed the most potent cytotoxic activity ($0.26{\mu}M<ED_{50}<2.16{\mu}M$) against all of the cell lines tested.

• the MEAT Journal
• /
• s.34 winter
• /
• pp.26-39
• /
• 2007

This study investigated the effect of salt and glucono-$\delta$-lactone (GdL) on the cold-set binding of restructured pork washed and pressurized at 200 MPa. Binding strength, pH, water holding capacity (WHC) and color were determined. NaCl improved pH, WHC and binding strength. GdL also increased binding strength while decreased WHC and pH significantly (p<0.05). However, low GdL level combined with NaCl showed high pH and WHC, compared to control. In color, NaCl decreased L*-value with increasing a*-value significantly (p<0.05). In contrast to NaCl, GdL increased L*-value and decreased a*-value. GdL tended to decrease b*-value and significant differences were found when GdL was added above 1%. Pearson’s correlation coefficients presented that NaCl had a significant effect on binding strength (0.6632) and lightness (?0.7330) while GdL had a significant correlation with all parameters barring binding strength. The results indicated that under washing and pressure treatments, GdL had a potential effect on cold-set binding with reducing NaCl concentration, especially when low GdL concentration combined with NaCl was added.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.11
• /
• pp.1806-1813
• /
• 2018

A new sesquiterpene lactone dimer [1], together with five known compounds (2-6), was isolated from the flowers of Inula britannica. The structures of these compounds were established by extensive spectroscopic studies and chemical evidence. The inhibitory activities of these isolated compounds (1-6) against human neutrophil elastase (HNE) were also evaluated in vitro; compounds 1 and 6 exhibited significant inhibitory effects against HNE activity, with $IC_{50}$ values of 8.2 and $10.4{\mu}m$, respectively, comparable to that of epigallocatechin gallate (EGCG; $IC_{50}=10.9{\mu}M$). In addition, compounds 3 and 5 exhibited moderate HNE inhibitory effects, with $IC_{50}$ values of 21.9 and $42.5{\mu}M$, respectively. In contrast, compounds 2 and 4 exhibited no such activity ($IC_{50}$ > $100{\mu}M$). The mechanism by which 1 and 3 inhibited HNE was noncompetitive inhibition, with inhibition constant ($K_i$) values of 8.0 and $22.8{\mu}M$, respectively.

• Journal of Environmental Science International
• /
• v.26 no.11
• /
• pp.1285-1295
• /
• 2017

Chrysanthemum boreale Makino is widely distributed in Korea, China, Japan and Southeast Asian countries. C. boreale is one of the herbs used for treating various inflammatory diseases in oriental medicine. The present study was conducted to identify biologically active compounds from the leaves and stems of C. boreale. We isolated two sesquiterpene sactones from the leaves and stems of C. boreale using silica gel column chromatography and recyclic high perfomance liquid chromatography. The lactones were characterized by their spectroscopic data (NMR, IR, MASS). These compounds were subjected to Farnesyl Protein Transferase (FPTase) inhibition, Nitric Oxide (NO) release inhibition and apoptosis inhibition. The structur of the following isolated compound were elucidated 8,10-${\small{O}$-Acetyl-2-methoxy-10-hydroxy-3,11(13)-guaiadiene-12,6-olide and 4,10-dihydroxy-8-${\small{O}$-Acetyl-2,11(13)-guaiadiene-12,6-olide. In the NO release inhibition assay, compound 2 showed strong activities, with an $IC_{50}$ value of $7{\mu}g/mL$, whereas compound 1 did not exhibit significant activity with an $IC_{50}$ value of over $14{\mu}g/mL$ against murine macrophage.

• Archives of Pharmacal Research
• /
• v.4 no.2
• /
• pp.133-135
• /
• 1981

Reaction of unsaturated acids with 3-bromo-5, 5-dimenthylhydantoin in dry DMF at room temperature gives bromolactones in 58-91 % yields.

• YAKHAK HOEJI
• /
• v.37 no.1
• /
• pp.100-106
• /
• 1993

Designed system, in which the $\beta$-hydroxy-$\delta$-lactone moiety is connected to benzimdazole ring by ethylene bridge, was propared from 2-sustd. benzimidazole as a potential HMG-CoA reductase inhibitor.

• Polymer(Korea)
• /
• v.26 no.2
• /
• pp.200-208
• /
• 2002

Two-component polyurethane flame-retardant coatings were prepared by blending trichloro lactone modified polyesters (TAPTS) and isocyanate, Desmodur IL. Polycondensation reaction of trichlorobenzoic acid (TBA) as a flame-retardant component, and adipic acid with trimethylolpropane, polycaprolactone 0201, and 1,4-butanediol gave the corresponding TAPTs. The content of TBA was adjusted from 10 to 30 wt% in our experiment. It was found that various properties of these new flame-retardant coatings were comparable to other non-flame-retardant coatings. We also carried out three different tests for the measurement of flammability of flame -retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TBA were determined as 'no burn'. The results of flammability test for the coatings with 20 and 30 wt% of TBA contents indicated the limiting oxygen index (LOI) values of 25% and 27% respectively, which implied relatively good flame retardancy. They also showed the char length of 3.6-5.2 cm according to $45^{\circ}$ Meckel burner test, which can be classified as the first grade flame-retardant coatings.