• Applied Biological Chemistry
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• v.48 no.4
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• pp.345-351
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• 2005

To access the natural products of uncultured microorganisms, we constructed and screened the metagenomic DNA libraries by using a cosmid vector and DNA inserts isolated directly from soil. Initial screening of the libraries in Escherichia coli resulted in the isolation of several clones that produce a dark brown color when grown in LB medium. One of the positive clones, designed pYS85C, was transposon mutagenized and the DNA surrounding the transposon insertions in cosmids that no longer conferred the production of brown pigment to E. coli was sequenced. Annotation of the pYS85C sequence obtained from the transposon mutagenesis experiment indicated a single 393 amino acid open reading frame (ORF) with a molecular mass of about 44.5 kDa, predicted to be a 4-hydroxyphenylpyruvate dioxygenases (HPPDs), was responsible for the observed brown pigment. In a BLAST search against deposited sequence, the translated protein from this ORF showed moderate-level identity (>60%) to the other known HPPDs and was most conserved in the C-terminal region of the protein. These results show that genes involved in natural product synthesis can be cloned directly from soil DNA and expressed in a heterologous host, supporting the idea that this technology has the potential to provide novel natural products from the wealth of environmental microbial diversity and is a potentially important new tool for drug discovery.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.236-244
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• 2024

Background: Fusarium oxysporum (F. oxysporum) is the primary pathogenic fungus that causes Panax notoginseng (P. notoginseng) root rot disease. To control the disease, safe and efficient antifungal pesticides must currently be developed. Methods: In this study, we prepared and characterized a nanoemulsion of Foeniculum vulgare essential oil (Ne-FvEO) using ultrasonic technology and evaluated its stability. Traditional Foeniculum vulgare essential oil (T-FvEO) was prepared simultaneously with 1/1000 Tween-80 and 20/1000 dimethyl sulfoxide (DMSO). The effects and inhibitory mechanism of Ne-FvEO and T-FvEO in F. oxysporum were investigated through combined transcriptome and metabolome analyses. Results: Results showed that the minimum inhibitory concentration (MIC) of Ne-FvEO decreased from 3.65 mg/mL to 0.35 mg/mL, and its bioavailability increased by 10-fold. The results of gas chromatography/mass spectrometry (GC/MS) showed that T-FvEO did not contain a high content of estragole compared to Foeniculum vulgare essential oil (FvEO) and Ne-FvEO. Combined metabolome and transcriptome analysis showed that both emulsions inhibited the growth and development of F. oxysporum through the synthesis of the cell wall and cell membrane, energy metabolism, and genetic information of F. oxysporum mycelium. Ne-FvEO also inhibited the expression of 2-oxoglutarate dehydrogenase and isocitrate dehydrogenase and reduced the content of 2-oxoglutarate, which inhibited the germination of spores. Conclusion: Our findings suggest that Ne-FvEO effectively inhibited the growth of F. oxysporum in P. notoginseng in vivo. The findings contribute to our comprehension of the antifungal mechanism of essential oils (EOs) and lay the groundwork for the creation of plant-derived antifungal medicines.

• Natural Product Sciences
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• v.11 no.1
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• pp.16-21
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• 2005

Nitric Oxide (NO), derived from L-arginine, is produced by two types (constitutive and inducible) of nitric oxide synthase (NOS: cNOS and iNOS). The NO produced in large amounts by the iNOS is known to be responsible for the vasodilation and hypotension observed in septic shock, cancer metastasis and inflammation. The inhibitors of iNOS, thus, may be useful candidates for the treatment of inflammatory diseases accompanied by the overproduction of NO. We prepared alcoholic extracts of herbal drugs which have been used for the treatment of inflammation in oriental medicine. We have screened the inhibitory activity of NO production in lipopolysaccharide (LPS)-activated macrophages after the treatment of these extracts. Among 82 kinds of extracts of herbal drugs, 35 extracts showed the potent inhibitory activity of NO production above 50% at the concentration of $50\;{\mu}g/mL$. The inhibitory activities of NO production were also evaluated for several solvent fractions at two different concentrations. Especially, hexane and EtOAc fractions of Alpinia officinarum, Angelica gigas, Ostericum koreanum, Saussurea lappa, Torilis japonica, and hexane fractions of Agrimonia pilosa, Machilus thunbergii, Hydrangea serrata, Magnolia obovata, Prunella vulgaris, Tussilago farfara, and EtOAC fractions of Perilla frutescence showed a significant activity at 10 and/or $25\;{\mu}g/mL$. In Western blot analysis, the hexane fractions ($5\;{\mu}g/mL$) of Magnolia obovata and Saussurea lappa, and EtOAc fractions ($20\;{\mu}g/mL$) of Hydrangea Serrata, Perilla frutescence and Torilis japonica inhibited the expression of iNOS protein in LPS-activated macrophages. These plants may be promising candidates for the study of the activity-guided purification of active compounds and might be useful for the treatment of inflammatory diseases and endotoxemia accompanying overproduction of NO.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.193-200
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• 2019

Ceramide metabolism is known to be an essential etiology for various diseases, such as atopic dermatitis and Gaucher disease. Glucosylceramide synthase (GCS) is a key enzyme for the synthesis of glucosylceramide (GlcCer), which is a main ceramide metabolism pathway in mammalian cells. In this article, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine GCS activity using synthetic non-natural sphingolipid C8-ceramide as a substrate. The reaction products, C8-GlcCer for GCS, could be separated on a C18 column by reverse-phase high-performance liquid chromatography (HPLC). Quantification was conducted using the multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z $588.6{\rightarrow}264.4$ for C8-GlcCer at positive ionization mode. The calibration curve was established over the range of 0.625-160 ng/mL, and the correlation coefficient was larger than 0.999. This method was successfully applied to detect GCS in the human hepatocellular carcinoma cell line (HepG2 cells) and mouse peripheral blood mononuclear cells. We also evaluated the inhibition degree of a known GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) on GCS enzymatic activity and proved that this method could be successfully applied to GCS inhibitor screening of preventive and therapeutic drugs for ceramide metabolism diseases, such as atopic dermatitis and Gaucher disease.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.29-38
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• 2023

Recent studies have highlighted the link between diseases and inflammation across our lifespan. Our sedentary lifestyle, high-calorie diet, chronic stress, chronic infections, and exposure to pollutants and xenobiotics, collectively intensify the course and recurrence of infections and inflammation in our bodies, promoting the prevalence of chronic diseases and aging. Given such phenomena and considering additional factors such as the frequency of prescription, and easy access to over-the-counter drugs, the need for anti-inflammatory therapeutics is ever-increasing. However, the readily available anti-inflammatory treatment option comes with a greater risk of side effects or high cost (biologics). Therefore in this growing competition of discovering and developing new potent anti-inflammatory drugs, we focused on utilizing the established knowledge of traditional medicine to find lead compounds. Since lead optimization is an indispensable step toward drug development, we applied this concept for the production of potent anti-inflammatory compounds achieved by structural modification of flavonoids. The derivative obtained through acetylation of myricetin, 3,3',4',5,5',7-hexaacetate myricetin, showed a greater inhibitory effect in the production of pro-inflammatory mediators such as nitric oxide, Prostaglandin E₂, and pro-inflammatory cytokines like interleukin-6, interleukin1β, in lipopolysaccharide-stimulated RAW264.7 mouse macrophage cells compared to myricetin. The increased potency of inhibition was in conjunction with an increased inhibitory effect on inducible nitric oxide synthase and cyclooxygenase-2 proteins. Through such measures, this study supports lead optimization for well-established lead compounds from traditional medicine using a simpler and greener chemistry approach for the purpose of designing and developing potent anti-inflammatory therapeutics with possibly fewer side effects and increased bioavailability.

• Natural Product Sciences
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• v.26 no.3
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• pp.200-206
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• 2020

The ability of the total extract from Physalis angulata; three fractions after partitioning with n-hexane, ethyl acetate (TBE), and water; and four withanolides (compounds 1 - 4) to phosphorylate 5'-adenosine monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) in HepG2 cells was evaluated. The TBE fraction (50 ㎍/mL) activated p-ACC and p-AMPK expression most strongly. Compounds 1 - 4 (10 μM) upregulated p-ACC expression at different levels. Compound 4 induced the most significant changes in p-AMPK expression, followed by 1 and 2. Sterol regulatory element-binding proteins (SREBPs) play a functional role in the transcriptional regulation of the lipogenic pathway, including fatty acid synthase (FAS) and ACC. The effects of compounds 2 and 4 (10 μM) on FAS and SREBP-1c expression under high glucose conditions (30 mM) in HepG2 cells were evaluated further. Both dose-dependently inhibited FAS and SREBP-1c expression as well as lipid accumulation (1 - 10 μM) were compared to high-concentration glucose control, which upregulated FAS and SREBP-1c. These results suggest that compounds 2 and 4 upregulate AMPK, suppress FAS and SREBP-1c, and have potential effects on glucose and lipid metabolism.

• Journal of radiological science and technology
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• v.33 no.4
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• pp.321-326
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• 2010

To examine the radioprotective effect of algin-oligosaccharide(AOS), radiation-induced IL(interleukin)-6 in mice treated with 3 Gy whole body irradiation once were examined. In the measurement of irradiation-induced IL-6, in comparison with the irradiation control group, in both small intestine and liver tissues of the group treated with algin-oligosaccharide for 7 days prior to irradiation, was suppressed IL-6 synthesis(p < 0.001). It is considered that the protection against radiation hazard by antioxydative reaction of algin-oligosaccharide results in down control of IL-6 value in experimental groups treated with algin-oligosaccharide. In conclusion, through our study, the fact that algin-oligosaccharide has irradiation protection effects was elucidated, and simultaneously, the possibility of the use of a natural product without chemical toxicity as an irradiation protection agent was confirmed.

• 한국유가공학회:학술대회논문집
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• 2005.06a
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• pp.13-35
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• 2005

The trend towards ageing populations has been observed over many years in Europe and the US but has accelerated significantly in developed countries in Asia including Japan and South Korea. In the latter country the elderly population (65+) has increased 5-fold between 1960 and 2000 and this group will comprise 40% of the population by 2050. This creates a new socio-economic group with specific demands and considerable spending power. As ageing occurs a range of changes occur in the body that can be moderated by adjustments in nutrition. A significant body of evidence points to changes in the balance of glutathione synthesis and utilisation as people age. Glutathione is the most important natural anti-oxidant of the body and the amounts present can become limited by available cysteine in the diet. A cysteine-enriched peptide product, Cysteine Peption$^{TM}$ has been developed by DMV International for dietary supplement and food applications. A qualitative consumer trial has indicated benefits including improved sleep and more energy. Animal and clinical trials will be described that provide indications on bioavailability and possible mechanisms of action of Cysteine Peption$^{TM}$ with particular focus on the ageing population.

• Journal of the Korean Chemical Society
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• v.46 no.3
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• pp.213-218
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• 2002

(${\eta}$5-Cyclopentadienyl)(${\eta}$6-1,2,3,4-tetramethyl-1,4-dibora-2,5-cyclohexadiene)Ni (5) was synthe-sizedas a main product by the reaction of cyclopentadienyl(carbonyl)nickel dimer and 1,2,3,4-tetramethyl-1,4-di-bora-2-cyclohexene (1). Di-allyl nickel reacted with 2,3-diethyl-1,4-di-methyl-1,4-dibora-2-cyclohexene (2) at -20$^{\circ}C$ to give bis(${\eta}$6-2,3-diethyl- 1,4-dimethyl-1,4-dibora-2,5-cyclohexadiene)nickel (6) in the yield of 15%. By the reaction of di-allyl nickel and 2,3-dimethyl-1,4-diethoxy-1,4-di- bora-2-cyclohexene (3) at -20$^{\circ}C$ bis[${\eta}$6-2,3-dim-ethyl-1,4-diethoxy-1,4-di- bora-2,5-cyclohexadiene]nickel (7) was obtained in 22% yield. These double-decker complexes were difficult to separate because of their unstabilities and were identified by ESR, NMR, MS and ele-mental analysis, etc.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.764-769
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• 1992

Strigol, a natural product isolated from root exudates of cotton, was found to be an extremely potent seed germination stimulant for the parasitic plant, witchweed. Witchweed seeds can remain dormant in the soil for several years until favorable conditions prevail including exposure to some type of chemical germination stimulant. Several strigol analogues, 3-methyl-4-(2-oxo-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-3-ylidenemethoxy)-but-2-en-4-olide(21), 4-(2-oxo-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-3-ylidenemethoxy)but-2-en-4-oilde(22), 3-methyl-4-(2-oxotetrahydrofuran-3-ylidenemethoxy)-but-2-en-4-olide(23), and 4-(2-oxotetrahydrofuran-3-ylidenemethoxy)-but-2-en-4-olide(24), were synthesized.