• The Journal of Korean Medicine
• /
• v.18 no.1
• /
• pp.169-186
• /
• 1997

Scutellariae Radix has been widely used as oriental herbal medicine for the treatment of bacterial infections in the respiratory or the gastrointestinal tract. In partition experiment for better understanding of herbal medicine with various solvents, baicalein or wogonin have more hydrophobic characteristics than baicalin or wogonoside. Unexpectedly, methylene chloride could extract more for baicalin or wogonoside over other active ingredients. New compound from baicalin is discovered casting frointier area on herbal medicine in the future. Application study with new molecule hydrolyzed from baicalin is on the way for better treatment of the patient against specific disease. The baicalin modified with reaction has been shown weak antibacterial activity against Streptococcus pyogenes 308A and Pseudomonas aeruginosa 1771. The minimum inhibitory concentration (MIC) of the baicalin modified compound against those strains were about $600\;{\mu}g/mL$, respectively. In vitro antitumor experiment, $EC_{50}$ of baicalin modified with reaction was more than $300\;{\mu}g/mL$ and $EC_{50}$ of baicalein was $100\;{\mu}g/mL$. Among these compounds, baicalin exhibited high level of antitumor activity. $EC_{50}$ of baicalin was less than $33.3\;{\mu}g/mL$.

• Microbiology and Biotechnology Letters
• /
• v.26 no.2
• /
• pp.137-142
• /
• 1998

Helicobacter pylori is a Gram-negative bacterium which causes chronic gastritis and is associated with gastric ulcer, duodenal ulcer and gastric carcinoma. In the process of screening of antibacterial activities against H. pylori from soil microorganisms, fungus No. 60686 was isolated. After fermentation of No.60686, the antibacterial compound was isolated, purified and followed by extraction of mycelium with organic solvents, acetone and ethyl acetate, through silica gel chromatography, LH-20 gel chromatography and HPLC. As a result of the structural analyses of the compound by IR, $^1$H- and $^{13}$C-NMR, FAB/Mass spectrophotometer, the compound having the antimicrobial activity was identified as chaetoglobosin A ($C_{32}H_{36}N_2O_5$), a cytochalasan derivative. The antimicrobial activity of chaetoglobosin A was tested against Gram-positive and negative bacteria by paper disk method. Among the test strains of 9 Gram-positive bacteria and 18 Gram-negative bacteria containing 4 H. pylori strains, the growth of 4 H. pylori strains and 3 S. aureus strains (SG 511, 285 and 503) was only inhibited by chaetoglobosin A. Also it was shown that its growth inhibition against H. pylori strains was stronger than that against S. aureus strains at the treatment of the same concentration. Therefore it was concluded that chaetoglobosin A has a specific growth inhibition against H. pylori of the tested bacteria.

• Journal of Marine Bioscience and Biotechnology
• /
• v.11 no.2
• /
• pp.42-51
• /
• 2019

We compared the antibacterial activities of spermidine and astaxanthin against two gram-positive bacteria such as Streptococcus parauberis and S. iniae to find new antibacterial candidates. We also evaluated the preventive effects of spermidine against oxidative stress-induced cytotoxicity in C2C12 myoblasts. Our results indicated that spermidine has more significant antibacterial activities than astaxanthin against both two fish pathogenic bacteria as well as gram-negative bacteria Escherichia coli used as a control group. Minimum inhibitory concentration and minimum bactericidal concentration of spermidine were 0.25 mM and 1 mM against S. parauberis, 1 mM and 3 mM against S. iniae, and 0.5 mM and 1.5 mM against E. coli, respectively. In addition, the postantibiotic effect lasted from 7 h, 5 h and 6 h for S. parauberis, S. iniae and E. coli, respectively. The results also showed that the decreased C2C12 cell viability by H₂O₂ could be attributed to the induction of DNA damage and apoptosis accompanied by the increased production of reactive oxygen species, which was remarkably protected by spermidine. Additionally, the antioxidant effect of spermidine was associated with the activation of Nrf2 signaling pathway. According to the data, spermidine may be a potential lead compound which can be further optimized to discover novel antibacterial and antioxidant agents.

• Journal of Food Hygiene and Safety
• /
• v.14 no.4
• /
• pp.346-351
• /
• 1999

To develop a lactic starter to produce antimicrobial substance for inhibiting the growth of a variety of foodborne spoilage bacteria in fermented foods, we investigated the anti-bacterial effect of the antibacterial substance, produced by Lactobacillus amylovorus IMC-1, against foodborne spoilage strains, and its sensitivity on the treatment of proteolytic enzymes. L. amylovorus IMC-1, which was isolated from a traditional cheese in Inner Mongolia, produced a maximum amount of antibacterial substance in the skim milk medium after 72 h incubation at 37$^{\circ}C$, and further incubation resulted in the same activity. The substance obtained from gel filtration inhibited all strains used such as Bacillus subtilis IFO 3025, Staphylococcus aureus IAM 1011, Listeria monocytogenes VTU 206, Escherichia coli RB, and Pseudomonas fragi IFO 3458 at the concentration of 20 units/ml. This substance was found to show bactericidal action against B. subtilis, E. coli, and Ps. fragi, and bacteriostatic activity against both Staph. aureus and L. monocytogenes. The bactericidal action was due to cellular Iysis. The substance is not organic acid, hydrogen peroxide and proteinaceous compound.

• Archives of Pharmacal Research
• /
• v.25 no.6
• /
• pp.807-816
• /
• 2002

Dihydrofolate reductases (DHFR) of human, Candida albicans and E. coli were docked with their original ligands of X-ray crystal complex using QXP (Quick eXPlore), a docking program. Conditions to reproduce the crystal structures within the root mean square deviation (rmsd) of 2.00 $\AA$ were established. Applying these conditions, binding modes and species-specificities of a novel antibacterial compound, $N^4-(2-acetoxyethoxymethyl)-2-acetylpyridine$ thiosemicarbazone (MTSC), were studied. As the results, the docking program reproduced the crystal structures with average rmsd of six ligands as 0.91 $\AA$ ranging from 0.49 to 1.45 $\AA$. The interactions including the numbers of hydrogen bonds and hydrophobic interactions were the same as the crystal structures and superposition of the crystal and docked structures almost coincided with each other. For AATSC, the results demonstrated that it could bind to either the substrate or coenzyme sites of DHFR in all three species with different degrees of affinity. It confirms the experimentally determined kinetic behavior of uncompetitive inhibition against either the inhibitor or the coenzyme. The docked MTSC overlapped well with the original ligands and major interactions were consistent with the ones in the crystal complexes. The information generated from this work should be useful for future development of antibacterial and antifungal agents.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.6
• /
• pp.1791-1794
• /
• 2013

Phytochemical investigation on dragon's blood of Dracaena cambodiana led to the discovery of two new flavonoid derivatives, cambodianin G (1) and cambodianin H (2). Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR techniques and chemical methods. The two compounds were observed to exhibit antibacterial activities against Staphylococcus aureus, and compound 1 showed cytotoxicities against K562 and SGC-7901 cell lines.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.2
• /
• pp.255-263
• /
• 2016

Antimicrobial properties of Licorice(Glycyrrhizae radix L.) against food spoilage microorganism, Bacillus subtilis KCTC 1021 was investigated. Antibacterial activity of the essential oil was as equivalent as Potassium metabisulfite and myconazole. The licorice extracts was fractionated to hexane, chloroform, ethyl acetate, butanol and water fraction. Chloroform fraction showed the highest inhibitory effect on the Bacillus subtilis KCTC 1021. Chloroform fraction was further fractionated by silica gel column chromatography and thin layer chromatography(TLC). The antibacterial compound was isolated from their fractions and its chemical structures was identified as (R)-glabridin by ESI-MS, $^1H$-NMR and $^{13}C$-NMR.

• Food Science and Biotechnology
• /
• v.18 no.5
• /
• pp.1301-1304
• /
• 2009

Macelignan is a bioactive compound isolated from nutmeg (Myristica fragrans Houtt.) which has been traditionally used for the food and pharmaceutical purposes. In this study, the activities of macelignan against vegetative cells and spores of Bacillus cereus were evaluated in vitro. Our results showed that the vegetative cells of B. cereus were significantly inhibited in growth by macelignan with minimum inhibitory concentration (MIC) of $4{\mu}g/mL$. The vegetative cells of B. cereus were completely killed with minimum bactericidal concentration (MBC) of $8{\mu}g/mL$ of macelignan. Killing time of macelignan against vegetative cells of B. cereus was very fast; endpoint of macelignan was reached after 4 hr of incubation at $4{\times}MIC$. Macelignan inactivated more than 3-log (99.9%) of spores/mL of B. cereus at the concentration of $100{\mu}g/mL$. Macelignan was found to be effective against vegetative cells and spores of B. cereus. These results suggest that macelignan might be good to be developed as a food preservative.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.17 no.3
• /
• pp.33-37
• /
• 2004

Objective: The aim of this work is to investigate the antibacterial activity of the Sohporaflavanone G isolated from Sophora flavescens (S. flavescens), as the development of microbial resistance to antibiotics make it essential to constantly look for new and active compounds effective against pathogenic bacteria. Method : Sophoraflavanone G was isolated from the dried roots of Sophora flavescens Aiton (Leguminosae) by bioassay?guided fractionation. We investigated the effect of sophoraflavanone G on oral bacterial at various concentrations after incubation of 24 h in strains in the dose?dependent manner. Results: The structure of active compound, Sophoraflavanone G having a lavandulyl group at C?8, was elucidated on the basis of spectral data especially 1H?NMR and I3C?NMR. The antimicrobial activity showed that Sophoraflavanone G exhibited antimicrobial activilies against all the bacteria tested (MICs, 0.39 - 6.25 ㎍／ml). Sophoraflavanone G showed the strong antimicrobial activity against all the facultative bacteria and microaerophilic bacteria (MICs, 0.78 - 1.56 ㎍／ml) and also Sophoraflavanone G showed the strong antimicrobial activity against obligate anaerobic bacteria (MICs, 0.39 - 6.25 ㎍／ml).

• Journal of Microbiology and Biotechnology
• /
• v.23 no.7
• /
• pp.932-941
• /
• 2013

This work aimed to classify Aspergillus (8 species, 28 strains) by using a secondary metabolite profile-based chemotaxonomic classification technique. Secondary metabolites were analyzed by liquid chromatography ion-trap mass spectrometry (LC-IT-MS) and multivariate statistical analysis. Most strains were generally well separated from each section. A. lentulus was discriminated from the other seven species (A. fumigatus, A. fennelliae, A. niger, A. kawachii, A. flavus, A. oryzae, and A. sojae) with partial least-squares discriminate analysis (PLS-DA) with five discriminate metabolites, including 4,6-dihydroxymellein, fumigatin, 5,8-dihydroxy-9-octadecenoic acid, cyclopiazonic acid, and neosartorin. Among them, neosartorin was identified as an A. lentulus-specific compound that showed anticancer activity, as well as antibacterial effects on Staphylococcus epidermidis. This study showed that metabolite-based chemotaxonomic classification is an effective tool for the classification of Aspergillus spp. with species-specific activity.