• Archives of Pharmacal Research
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• 제27권9호
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• pp.885-892
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• 2004

Due to the rapidly growing number of resistant strains of bacteria, the search for antibacterial agents with new modes of action will always remain an important and challenging task. Thus, the reaction of 2-substituted or. unsubstituted-4-(4-acetylanilino)-5,6,7,8-terahydrobenzo［b］ thieno［2,3-d］pyrimidine derivatives 1-3 with the hydrazine derivatives, semi and / or thiosemi-carbazides, provided the corresponding hydrazones 4-6 and semi and/or thiosemicarbazones 7-9. Claisen-Schmidt condensation of compounds 1 or 2 with the appropriate aldehyde yielded the chalcones 10, 11 which, when treated with hydroxylamine hydrochloride gave rise to the isoxazoline-containing compounds 12, 13. Furthermore, reacting the respective chalcones 10, 11 with different hydrazines, urea and/or thiourea, furnished compounds 14, 15, 16, and 17 respectively. Representative compounds were tested for their antimicrobial activity against Candida Albicans and certain gram-positive and gram-negative bacteria. Their MICs were then determined. Compound 15e, showed a broad spectrum of activity while most of the other com-pounds showed varying antimicrobial activity.

• BMB Reports
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• 제30권3호
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• pp.229-233
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• 1997

Indolicidin has been known to have a broad spectrum of antimicrobial activities against Gram negative and positive bacteria. Its eight analogues were chemically synthesized. The analogue design was based on the analysis of sequence to elucidate the role of some residues in the antibacterial mechanism of indolicidin. Bactericidal activities were assayed against Escherichia coli and Proteus vulgaris, and the membrane perturbing abilities of the peptides were assayed using a dye containing liposome. Among the eight analogues, $[Gly^4, Gly^6]-Indo,\;[Ile^6,Ile^8]-Indo,\;[Lys^{12}]-Indo$ and $[Thr^2,Tyr^9]-Indo$ showed enhanced antibacterial activities. These results suggest that proline and cationic residues are important in the bactericidal activity of indolicidin. We tried to describe the antimicrobial mechanism of indolicidin with these results.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3684-3692
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• 2010

A series of azole-containing piperazine derivatives have been designed and synthesized. The obtained compounds were investigated in vitro for their antibacterial, antifungal and cytotoxic activities. The preliminary results showed that most compounds exhibited moderate to significant antibacterial and antifungal activities in vitro. 1-(4-((4-chlorophenyl) (phenyl)methyl)piperazin-1-yl)-2-(1H-imidazol-1-yl)ethanone and 1-(4-((4-Chlorophenyl)(phenyl)methyl)piperazin-1-yl)-2-(2-phenyl-1H-imidazol-1-yl)ethanone gave remarkable and broad-spectrum antimicrobial efficacy against all tested strains with MIC values ranging from 3.1 to $25\;{\mu}g/mL$, and exhibited comparable activities to the standard drugs chloramphenicol and fluconazole in clinic. Moreover, 2-((4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)methyl)-1H-benzo[d]imidazole was found to be the most effective in vitro against the PC-3 cell line, reaching growth inhibition values (36.4, 60.1 and 76.5%) for each tested concentration: $25\;{\mu}g/mL$, $50\;{\mu}g/mL$ and $100\;{\mu}g/mL$ in dose-dependent manner. The results also showed that the azole ring had noticeable effect on their antimicrobial and cytotoxic activities, and imidazole and benzimidazole moiety were much more favourable to biological activity than 1,2,4-triazole.

• Biomolecules & Therapeutics
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• 제13권4호
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• pp.240-245
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• 2005

An antimicrobial molecule was purified from centipede, Scolopendra subspinipes mutilans L. Koch, by reverse phase-HPLC. Its molecular weight was determined to be 1208.5493 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Total amino acid composition analysis revealed that it consists of E, G, P, V, L, F, and W. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram-positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin resistant enterococci (VRE). It may be a useful molecule for a new antibiotic development, especially against drug-resistant bacteria. We suggest that it may playa role in the defense system of this animal. This is the first report of a peptidic antimicrobial substance from centipede.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.61-74
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• 2023

The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 ㎍/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC₅₀ values of 47.15 ± 13.10 and 122.69 ± 9.12 ㎍/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.

• 생명과학회지
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• 제31권1호
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• pp.83-89
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• 2021

개불 라이소자임(Uu-ilys)은 개불(Urechis unicinctus)로부터 정제된 무척추형 라이소자임으로 병원균에 대한 방어에 주요하게 작용하는 선천성 면역 물질이며, 비효소적 항균 활성을 가지고 있어 항균 활성을 지닌 유도체의 개발 가능성을 가지고 있다. 본 논문은 개불 라이소자임에서 유래된 항균 활성을 가지는 유도체의 디자인과 생산을 기술하고 있다. 여러 항균성 펩타이드(antimicrobial peptide, AMP) 데이터베이스에서 제공하는 항균성 펩타이드 예측 도구를 사용하여 개불 라이소자임에서 항균 활성을 가지는 부위를 예측하였다. 개불 라이소자임 C-말단의 절편이 항균 활성을 나타낼 것으로 예측되었으며, 이 펩타이드는 C-말단 절편, Uu-ilys-CF라 명명하였다. Uu-ilys-CF은 이형 발현 시스템인 TrxA-Uu-ilys-CF 퓨전 단백질을 사용하여 생산하였다. 만들어진 퓨전 단백질은 브롬화시안을 사용하여 메티오닌 잔기를 절단하였으며, 절단된 Uu-ilys-CF은 고성능액체크로마토그래피와 역상 컬럼인 CapCell-Pak C18을 사용하여 분리되었다. Uu-ilys-CF의 항균 활성을 조사하기 위해서 여러 균주(그람양성균 4개, 그람음성균7개, 진균 1개)를 사용하였다. Uu-ilys-CF의 항균 활성은 살모넬라에서 가장 높은 반응을 보였다. 비록 Uu-ilys-CF는 진균에 활성을 나타내지 않았지만, 사용한 균주들에서 넓은 범위의 항균 활성을 나타내었다.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.610-614
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• 1998

DW-116, [1-(5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-1-piperazinyl)-1,4-dihydro-4-oxoquino-line-3-carboxylic acid hydrochloride}, is a new quinolone antibiotic with a broad antibacterial spectrum against G(+) and G(-) bacteria. DW-116 was evaluated for the immunomodulating activities, which is one of the efforts to investigate the mechanism of action related to the good in vivo antibacterial efficacy. The results of in vitro studies revealed there was no statistically significant increase in B and T lymphocyte proliferation. But the results of in vivo studies showed that the number of plaque forming cells (PFC), the amount of polyclonal antibodies and delayed-type hypersensitivity (DTH) were significantly increased after the repeat administration with 12 and 60 mg/kg of DW-116. Taken together, these results proposed that immunostimulting effect of DW-116 could be one of the action mechanisms for demonstrating in vivo antibacterial activities under these experimental conditions.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.669-671
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• 2000

Antimicrobial cationic peptides have attracted increasing research and clinical interest as a natural antibiotics due to their broad spectrum of antimicrobial activites and the rapid development of multidrug-resistant pathogenic microorganisms. In this study, first, we synthesized artificial fusion partner and cationic peptide genes (lactoferricin, magainin, protegrin-1, and indolicidin). Second, we constructed recombinant expression vectors and then transformed Pichia pastoris. Finally, expressed cationic peptides were purified and tested for their antimicrobial activites. Antimicrobial activity has been tested upon the appearance of clearing zone on the plate with the lawn of gram negative E.coli XL- I blue and garm positive Staphylococcus aureus. Protegrin-1 and Indolicidin have apparant activity of cationic peotides. This fusion technique may lead to a general and suitable tool for production of pure antimicrobial cationic peptides in Pichia pastoris.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.79-79
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• 2001

Genotoxic chemotherapeutics are irreversible DNA targeting agents, which can act as anticancer and antiviral drugs. Natural antibacterial and anticancer enediynes function through the formation of free radicals formed by Bergman-type cycloaromatization and being capable of cleavage of DNA strand. They have been focused primarily on the design and syntheses of simple enediyne structures, which can be mimic their mechanistic feature. Recently. I have been reported the possible application of 4'-bromoacetophenone as a simple photoactivatable DNA cleaving agent, which could be readily prepared and exhibit potent and selective DNA cleaving activity. Herein, we further investigated the activity of 4'-bromoacetophenone-pyrrolecarboxamides, which consist of both DNA cleaving element and recognition unit under various conditions in order to get more understanding of the mechanism of the action and find a broad spectrum of application.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.349-350
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• 2002

햄은 부패에 의한 폐기율이 높은 식품으로서 본 연구에서 개발한 식물유래 천연방부제들 즉 향나무, 대나무, 소목, 쑥 등의 알콜추출물의 첨가에 의한 실용화 가능성이 높았다.