• Journal of Integrative Natural Science
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• v.1 no.1
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• pp.47-53
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• 2008

In a previous study, we showed that Cecropin A (1-8)-Magainin 2 (1-12) hybrid peptide (CA-MA)'s analogue, Anal P5, exhibit broad-spectrum antimicrobial activity. Anal P5, designed by flexible region (positions 9, 10)-substitution, Lys- (positions 4, 8, 14, 15) and Leu- (positions 5, 6, 12, 13, 16, 17, 20) substitutions, showed an enhanced antimicrobial and antitumor activity without hemolysis. The primary objective of the present study was to gain insight into the relevant mechanisms of antimicrobial activities of Anal P5 by using flow cytometric analysis. Anal P5 exhibits strong antifungal activity in a salt concentration independent manner. In addition, Anal P5 causes significant morphological alterations of the bacterial surfaces as shown by scanning electron microscopy, supporting its antibacterial activity. Its potent antibiotic activity suggests that Anal P5 is an excellent candidate as a lead compound for the development of novel antibiotic agents.

• International Journal of Oral Biology
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• v.35 no.4
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• pp.177-184
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• 2010

In our present study, we investigated the effects of continentalic acid on Streptococcus mutans (S. mutans) biofilm. Methanol extract of Aralia continentalis (A. continentalis) was suspended in water and sequentially partitioned with CHCl3, ethyl acetate (EtOAc), and n-butanol (n-BuOH). The CHCl3 fraction showed the highest activity and an antibacterial compound against S. mutans was isolated from this preparation through various chromatography methods by bioassay guided fractionation. MS, $^1H-NMR$ and $^{13}C-NMR$ analysis showed that the active principle was continentalic acid which was confirmed to show significant inhibitory effects against S. mutans biofilm. These results may provide some scientific rationale for the traditional use these extracts for the treatment of dental diseases.

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.223-227
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• 2000

Propolis, a natural resinous compound collected from honey bees, contains many biochemical constituents and has been used for traditional medicines as early as 300 B .C. Recently, it has been reported to possess many biological activities such as antibacterial, antiviral, fungicidal, local anaesthetic, immunostimulating, antiinflammatory and free radical scavenging properties. To investigate activities of chrysin, one of propolis effective compounds for blood coagulation system was injected endotoxin (4000 EU/kg, i.v.) in rats at 1 hr after administered chrysin (20 mg/kg, p.o.). This study was resulted that chrysin has antiplatelet aggregation activity in vitro, delay of blood clotting time and prothrombin time, and reduction of fibrinogen and FDP in vivo. Chrysin has increased SOD activity, GSH content and GST activity, and decreased MDA content in liver. The result suggests that the antithrombosis effect of chrysin is suppressive activity for a blood coagulation system and antioxidative activity.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.311-314
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• 1992

A new monocyclic ${\beta}-lactam$ analogue, sodium (3R,4S)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (3) was synthesized from L-aspartic acid. Starting from L-aspartic acid, (S)-1-benzyl-4-benzyloxycarbonyl-2-azetidinone (7) was synthesized in four steps by following the established procedures and converted into (3R,4S)-3-amino-1-t-butyldimethylsilyl-4-methoxym ethyl-2-azetidinone (13) in six steps. Acylation of the amino group of 13 with $2-amino-{\alpha}$ -(methoxyimino)-4-thiazoleacetic acid, desilylation, and sulfonation with sulfur trioxide-pyridine complex followed by ion exchange afforded sodium (3R,4S)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (3). Antibacterial activities of this ${\beta}$ -lactam compound 3 were, however, found to be quite low compared to cefotaxime.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.315-316
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• 1992

Sodium (3S,4R)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (2) was synthesized in fourteen steps from D-aspartic acid. Starting from D-aspartic acid, (3S,4R)-3-amino-1-t-butyldimethylsilyl-4-methoxym ethyl-2-azetidinone (12) was synthesized in ten steps. Acylation of the amino group of 12 with $2-amino-{\alpha}-(methoxyimino)-4-thiazoleacetic$ acid, desilylation, sulfonation, and ion exchange afforded sodium (3S,4R)-3-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyi minoacetamido]-4-methoxymethyl-2-azetidinone-1- sulfonate (2). This new ${\beta}-lactam$ compound 2 showed low antibacterial activities.

• Korean Journal of Pharmacognosy
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• v.54 no.1
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• pp.16-20
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• 2023

KSM-2690 B (1), a peptide-polyketide hybrid compound, was discovered from an actinomycete strain (CJD 1) isolated from Dong-Baek hill on Jeju Island, Republic of Korea. The chemical structure of 1 was identified by using NMR, MS, and UV spectroscopic analyses. Careful analysis of 1D and 2D NMR data revealed that KSM-2690 (1) has an oxazole ring, a β-lactone-γ-lactam spirocycle ring, and both triene and diene structures. KSM-2690 B (1) showed inhibitory activities against E. coli at 200 ㎍/mL.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.694-705
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• 2017

The aim of this study was to isolate and identify marine bacterium with anti-methicillin-resistant Staphylococcus aureus (MRSA) activity, and to purify the anti-MRSA compound, as well as to determine its activity and synergistic effects. Among the marine bacteria isolated in this study, the YJ-1 isolate had the strongest anti-MRSA activity. The YJ-1 isolate was identified on the basis of its biochemical characteristics and an analysis of 16S rRNA gene sequences. The YJ-1 isolate showed over 99.2% homology with Pseudomonas stutzeri, and was designated as a Pseudomonas sp. YJ-1. The optimal culture conditions were $25^{\circ}C$ and initial pH 7.0. For the purification of the anti-MRSA compounds, the YJ-1 was cultured in Pa PES-II medium, and the culture filtrates were extracted by ethyl acetate, hexane, and 80% MeOH. The 80% MeOH fraction was separated by a $C_{18}$ ODS column, silica gel chromatography and a reverse phase HPLC, to yield three anti-MRSA agents, the MR1, MR2, and MR3 compounds. When the MR1 compound of $250{\mu}g\;mL^{-1}$ concentration was applied to the MRSA cells, over 95% of bacterial cells was killed within 48 hr. Compared with vancomycin and ampicillin, the MR1 compound showed significant anti-MRSA activity. In addition, the anti-MRSA activity was increased by dose and time dependent manners. Furthermore, the combination of an MR1 compound with vancomycin produced a more rapid decrease in the MRSA cells than did the MR1 compound alone. Taken together, our results suggest that the Pseudomonas sp. YJ-1 and its anti-MRSA compounds could be employed as a natural antibacterial agent in MRSA infections.

• Advances in Traditional Medicine
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• v.8 no.4
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• pp.339-348
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• 2008

Butea frondosa has been used traditionally as a topical formulation in the treatment of many diseases and disorders. Two compounds [BF-1 (crystalline flavonol quercetin) and BF-2 (tannin) from ethyl acetate fraction of ethanolic extract] were isolated from the bark of Butea frondosa. The stereostructures of the compounds were determined on the basis of chemical and physicochemical evidence. BF-1 and BF-2 were screened in vitro for possible antibacterial property against 112 bacteria comprising 3 genera of Gram-positive and 12 genera of Gram-negative types. It was found that both BF-1 and BF-2 exhibited inhibitory activity against several bacteria. Most of these strains were inhibited by BF-1 at $50-200\;{\mu}g/ml$, while BF-2 ($MIC_{50}$ $400\;{\mu}g/ml$) was much less active. The bacteria could be arranged in the decreasing order of sensitivity towards BF-1 in the following manner: S. aureus, Bacillus spp., Salmonella spp., Vibrio spp., Shigella spp., E. coli and Pseudomonas spp. The $MIC_{50}$ of the compound was $50\;{\mu}g/ml$ while the $MIC_{90}$ was $100\;{\mu}g/ml$. The decreasing order of sensitivity towards BF-2 was V. cholerae, Bacillus spp., S. aureus, V. parahaemolyticus, Salmonella spp. and Proteus spp. BF-1 was bactericidal in action. In vivo studies with this extract showed that it could offer statistically significant protection (p < 0.01) to mice challenged with a virulent bacterium. The inhibitory activity of Butea frondosa against Gram-positive and Gram-negative bacteria indicates its usefulness in the treatment of common bacterial infections. The potentiality of BF-1 as an antibacterial agent may be confirmed further by pharmacological studies.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2260-2266
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• 2011

4-Chlorotetrazolo[1,5-a]quinoxaline (III) was synthesized by azide (2+3) cycloaddition of 2,3-dichloroquinoxaline (II). Compound (III) on further refluxing with hydrazine hydrate furnished 4-hydrazinotetrazolo[1,5-a]quinoxaline (IV). Further refluxing of (IV) with different aromatic aldehydes in methanol yielded corresponding Schiff's bases V(a-j). Various 4-aminotetrazolo[1,5-a]quinoxaline based azetidinones VII(a-j) were synthesized by stirring the compounds V(a-j), at low temperature, with equimolar mixture of chloroacetylchloride & triethylamine in dry benzene, while 4-aminotetrazolo[1,5-a]quinoxaline based thiazolidinones VIII(a-j) were synthesized by refluxing Schiff's bases V(a-j) with thioglycolic acid in oil-bath. The structures of all the compounds were confirmed on the basis of $^1H$-NMR & FT-IR spectral data. All the newly synthesized compounds were screened for in-vitro antimicrobial activity against E. coli, S. aureus, K. pneumoniae & P. aeruginosa & antifungal activity against C. albicans. Few of them have exhibited the promising activity.

• Fashion & Textile Research Journal
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• v.18 no.6
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• pp.869-877
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• 2016

This study looks into the dyeing properties and functionality of cotton fabrics dyed in both the Spirodela polyrhiza extract and the extract resulting from the mixture of Salvia plebeia R. Br. and Spirodela polyrhiza. Since the UV-Vis Spectrum of the methanol extract of Spirodela polyrhiza shows absorption peaks at 256, 268nm, and 345nm, it can be inferred that the compound that Spirodela polyrhiza contains is a flavonoid. In addition, it can also be presumed that, by analyzing the infrared absorption spectrum of Spirodela polyrhiza, the plant contains flavonoid compounds, just like Salvia plebeia R. Br.. The UV protection factors of the cotton fabrics dyed in both the Spirodela polyrhiza extract and the extract from the mixture of Salvia plebeia R. Br. and Spirodela polyrhiza were 50+, presenting outstanding UV protection factors. The deodorization rate of the cotton dyed in the Spirodela polyrhiza extract was between 30 and 120 minutes, and the rate rose from 92% to 97% as time passed. The deodorization rate of the cotton dyed in the extract from the mixture of Salvia plebeia R. Br. and Spirodela polyrhiza increased from 88% to more than 91%. The result also revealed that overall the fastness of color, including color fastness to washing related to change in color, as well as the color fastness to light of the fabric dyed in the extract from the mixture of the two plants improved, compared to the cloth dyed only in Spirodela polyrhiza extract. Furthermore, the antibacterial activity was also strengthened.