• 생명과학회지
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• 제25권7호
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• pp.748-756
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• 2015

본 연구는 기존의 선행 연구된 천연물 중 항균활성이 가장 좋은 황련, 오배자, 피톤치드(Phytoncide)가 단일추출물과 추출혼합물 일 때 M. furfur의 항균활성 차이에 대한 효과를 알아보고자 하였고, 선행연구에서 비듬균에 대한 천연한방추출물의 항균활성결과와 비교하였다. 추출혼합물에서 S. aureus는 3가지 혼합한 천연물질에서 항균활성이 내성하였으며 E. coli는 황련과의 혼합물에서 내성하였고 C. albicans는 오배자와 혼합물에서 내성이있는 것으로 나타나 각 균주에 따라 항균활성이 다른 것으로 나타났다. 반면 M. furfur는 단일추출물에서 전혀 항균활성이 없었고, 혼합물에서는 황련과 피톤치드 50% 혼합물에서 3.20mm의 직경으로 미약한 항균활성을 보였다. 이는 같은 진균인 C. albicans와 비교하여 볼 때 현저한 차이가 있었다. 그 이유는 M. furfur가 C. albicans에 비하여 세포벽이 지방친화성 성분을 지니고 있고 라멜라층, 원형질내막, 중간 다층구조로 되어있기 때문이라고 사료된다.

• 한국식품위생안전성학회지
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• 제35권4호
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• pp.382-390
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• 2020

S. aureus, E. coli, C. albicans, A. niger 등 4종의 식중독균에 대해 agar diffusion법을 이용하여 홍삼(Panax ginseng C.A.Meyer)으로 부터 조제한 홍삼농축액, 조사포닌, 비수용성 분획에 대한 항균활성을 조사하였다. 그 결과, 홍삼농축액 및 비수용성분획은 E. coli, C. albicans, A. niger에 대해서는 항균활성을 나타내지 않았고 조사포닌도 고농도인 30%를 제외한 모든 농도에서 항균활성을 나타내지 않았다. S. aureus는 Gram positive 세균으로서 화농성 식중독의 원인균이면서 동시에 아토피성 피부염의 원인균으로 알려져 있는데, 홍삼농축액은 30% 농도에서 이 균에 대해 항균활성을 나타내었고 조사포닌도 7.5%에서 항균활성을 나타내었다. 홍삼으로부터 조제한 비수용성 분획도 10~200 mg/mL 농도로 실험한 결과 모든 분획에서 항균효과를 나타내었다. 조사포닌 및 홍삼농축액의 미생물 생육저해양상을 조사하기 위해 미리 S. aureus를 접종한 0.85% 생리식염수에 농축액 및 조사포닌을 농도별로 첨가하고 35℃, 12시간 배양한 후 생균수를 측정한 결과, 홍삼농축액은 10% 이상의 농도에서, 조사포닌은 2% 이상의 농도에서 각각 균의 생육을 억제하였다. 그러나 이러한 농도에서도 생균수는 완전히 사멸되지 않아서 홍삼농축액 및 조사포닌의 S. aureus에 대한 생육억제작용은 살균작용이 아닌 정균 작용으로 추정되었다. 사포닌의 항균활성 유무를 확인하기 위해 순수 분리된 ginsenoside 6종(PT saponin, PD saponin, ginsenoside-Rb₂,-Rc,-Rd,-Rf,-Rg₂)의 항균활성을 50~200 ㎍/mL의 농도에서 조사한 결과 모두 항균효과가 관찰되지 않아서 ginsenoside는 S. aureus에 대해서는 항균효과가 없는 것으로 사료된다. 한편 사포닌을 제외한 비사포닌 성분인 비수용성분획에 대해 상기의 4종 병원성미생물을 대상으로 항균활성을 조사한 결과 E. coli, C. albicans, A. niger에 대해서는 항균효과가 관찰되지 않았고 S. aureus에 대해서만 선택적인 항균활성을 나타내었다. 항균활성 발현 비수용성분획 중 15% methanol분획(MF-1)이 가장 높은 항균활성을 나타내어 이에 대한 최소생육저해농도를 조사한 결과 0.625 mg/mL 이었다. MF-1 분획을 질량분석기(HPLC-MS)로 조사한 결과 주요한 활성성분은 분자량 179.55 및 187.55를 가지는 물질로 추정되었다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.795-800
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• 2002

6,7-Bis-[S-(aryl)thio]-5,8-quinolinediones 4 and 5 were synthesized by the substitution of 6,7-dichloro-5,8-quinolinediones with appropriate arylthiols. Their antifungal activity were tested in vitro for their growth inhibitory activities against pathogenic fungi in comparison with flucytosine. The antifungal activities were significantly improved by S-(aryl)thio moieties of the compounds 4 and 5. The all tested compounds 4 and 5 showed generally good activities against C. albicans and A. niger ranging from 0.8 to 25 $\mu\textrm{g}$/ml. Among them, compounds 4d-4h and 5a-5c exhibited also good activities against C. krusei and C. tropicalis. The activities of compounds 4j and 4I were comparable to those of flucytosine against all tested fungi.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.807-816
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• 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.

• Mycobiology
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• 제36권2호
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• pp.93-98
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• 2008

Two Schiff base ligands $L_1\;and\;L_2$ were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1:1 electrolytes. The IR data demonstrate the tetradentate binding of $L_1$ and tridentate binding of $L_2$. The XRD data show that Zn(II) complexes with $L_1\;and\;L_2$ have the crystallite sizes of 53 and 61 nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.

• Mycobiology
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• 제40권1호
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• pp.8-13
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• 2012

In the present study, an attempt to evaluate the antimicrobial and antioxidant activity of fungal endophytes inhabiting $Emblica$ $officinalis$ has been made keeping in view the medicinal importance of the selected host plant in Indian traditional practices. A total of four endophytic fungi belonging to Phylum Ascomycetes were isolated from different parts of the plant which were characterized morphologically and by using rDNA-internal transcribed spacer. The most frequently isolated endophyte was $Phomopsis$ sp. The antioxidant activity by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power assay, and total phenol were evaluated using ethanolic extract of endophytic fungi. DPPH activities in all the ethanolic extract increased with the increase in concentrations. Endophytes, $Phomopsis$ sp. and $Xylaria$ sp. showed highest antioxidant activity and also had the higher levels of phenolics. Antimicrobial activity of fungal extract were tested against four bacteria namely, $Escherichia$ $coli$ MTCC730, $Enteroccocus$ $faecalis$ MTCC2729, $Salmonella$ $enterica$ ser. $paratyphi$ MTCC735 and $Streptococcus$ $pyogenes$ MTCC1925, and the fungus $Candida$ $albicans$ MTCC183. In general, the fungal extracts inhibited the growth of test organisms except $E.$ $coli$.

• 약학회지
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• 제46권6호
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• pp.416-425
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• 2002

A comparative study to validate the reliability of a fully automated docking program, FlexiDock, was carried out to predict the binding modes of DHFR-inhibitor complex. The inhibitors were extracted from the crystallographically determined DHFR-NADP$^{+}$(H)-inhibitor ternary complexes of human, Escherichia coli and Candida albicans and then docked back into the remaining DHFR-NADP$^{+}$(H) binary complexes using FlexiDock. The resulting conformations and orientations were compared to the original crystal complex structures for reproducibility. Then, folate, the substrate, and known inhibitors such as methotrexate, piritrexim and trimethoprim were docked into the wild-type human DHFR and their binding modes were compared with X-ray crystallographic or other modeling data. The root mean square deviations (RMSDs) for ligands ranged from 1.14 to 1.57$\AA$, and the protein backbone RMSDs from 0.94 to 1.26$\AA$. FlexiDock reproduced the orientations and binding modes of all seven ligands in good agreement with the crystal structures. It proved to be a reliable and efficient program in studying binding modes of DHFR-inhibitor complexes of different species, and the information obtained from this work may provide additional insight into the design of new agents with improved activity.ity.

• 대한임상검사과학회지
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• 제45권4호
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• pp.154-158
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• 2013

The unnatural dead body refers to a corpse which is suspicious of unusual death and the dead case has been occurred more than 20 thousands times every year during the recent five years and most of them are found decayed. Police Scientific Investigators investigate unnatural dead bodies and its surroundings in all-around way and determine whether the death is involved with a crime, and most of the Scientific Investigators are exposed to a danger to get infected with pathogenic bacteria which are generated during the decaying process of dead body and are mostly to cause serious injuries on human beings. In line with the fact, the present study conducted a bacterial analysis by collecting excretions from 60 dead bodies and culturing the bacteria to evaluate infection risk of the police agents. The study cultured bacteria from 60 bodies and classified pathogenic bacteria of 108 strains, and its main bacteria are found to be them (; Acinetobacter baumannii 20 strains (19%), Pseudomonas aeruginosa 19 strains (18%), E. coli 18 strains (17%), Klebsiella pneumoniae 11 strains (10%), Proteus mirabillis 10 strains (9%), Enterococcus faecium 10 strains (9%), Staphylococcus aureus 9 strains (8%), Bacillus spp. 5 strains (5%), Streptococcus pneumoniae 3 strains (3%), Candida albicans 2 strains (2%), Mycobacterium tuberculosis 1 strains (1%)). The study results are expected to be used as educational data for preventing the Police Scientific Investigator from infections with bacteria or as a minimum data for improving work environment of the agents.

• 생약학회지
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• 제42권4호
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• pp.336-340
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• 2011

The aim of this study was to investigate the possible utilization of Zanthoxylum schinifolium as a source of antimicrobial agents. The antimicrobial effects of Zanthoxylum schinifolium extracts were investigated against Acinetobacter baumannii, which is a multi-drug resistant pathogen, and 5 other pathogenic microorganisms. The hexane extract of Zanthoxylum schinifolium was more effective than the ethyl acetate, n-butanol and methanol extracts which were active against Acinetobacter baumannii 25, with minimum inhibitory concentrations(MIC) ranging from 0.8 mg/ml to 1.6 mg/ml. Tetracycline had no effect on Acinetobacter baumanniii. The hexane extract was highly active against Candida albicans IFO 6258, with an MIC of 1.5 mg/ml. In contrast, the ethyl acetate, n-butanol and methanol extracts showed no activity against the 5 pathogenic microorganisms. Furthermore, a combination of hexane extract and ethyl acetate extract was significantly more active against the 5 Acinetobacter baumannii strains than n-butanol and methanol. These results suggest that Zanthoxylum schinifolium extracts have great potential as antimicrobial compounds against multi-drug resistant pathogens, and further studies are warranted.

• The Journal of Advanced Prosthodontics
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• 제3권1호
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• pp.20-24
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• 2011

PURPOSE. The aim of this study was to identify in vitro antimicrobial activity of the tissue conditioner containing silver nanoparticles on microbial strains, Staphylococcus aureus, Streptococcus mutans and Candida albicans. MATERIALS AND METHODS. Experimental disc samples ($20.0{\times}3.0$ mm) of tissue conditioner (GC Soft-Liner, GC cooperation, Tokyo, Japan) containing 0.1 - 3.0% silver nanoparticles (0%: control) were fabricated. Samples were placed on separate culture plate dish and microbial suspensions (100 ${\mu}L$) of tested strains were inoculated then incubated at $37^{\circ}C$. Microbial growth was verified at 24 hrs and 72 hrs and the antimicrobial effects of samples were evaluated as a percentage of viable cells in withdrawn suspension (100 ${\mu}L$). Data were recorded as the mean of three colony forming unit (CFU) numerations and the borderline of the antimicrobial effect was determined at 0.1% viable cells. RESULTS. A 0.1% silver nanoparticles combined to tissue conditioner displayed minimal bactericidal effect against Staphylococcus aureus and Streptococcus mutans strains, a 0.5% for fungal strain. Control group did not show any microbial inhibitory effect and there were no statistical difference between 24 hrs and extended 72 hrs incubation time (P > .05). CONCLUSION. Within the limitation of this in vitro study, the results suggest that the tissue conditioner containing silver nanoparticles could be an antimicrobial dental material in denture plaque control. Further mechanical stability and toxicity studies are still required.