• KSBB Journal
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• v.17 no.4
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• pp.345-349
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• 2002

The adsorption of the antimicrobial compounds(AMCs) and their heat-resistance were investigated for the packaging film manufacture, wherein, the antimicrobial compounds were adsorbed on a silica component. The naturally source antimicrobial compounds were produced by methylotropic actinomycetes strains MO-16 and MO-17, extracted with ethylacetate. Antimicrobial compounds adsorbed on water-soluble silica had retained activity against Gram(+) and the Gram(-) bacteria after heat treatment at 150$\^{C}$ for 5min. The benzoic acid showed strong antimicrobial activity to fungi and was stable to heat treatment. The combination of antimicrobial compound plus benzoic acid was synergistic against test strains. Therefore, we estimated that the water-soluble silica is suitable for the packaging film manufacture as a adsorbent of the antimicrobial compounds.

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.391-398
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• 1999

A methylotrophic actinomycetes strain MO-16, which produce the antimicrobial compound, was isolated from soil and supposed as Amycolatopsis sp. based on taxonomic studies. The cell-free extract of methanol-grown strain MO-16 showed dehydrogenase activity for methanol and formaldehyde when various electron acceptors were added for oxidation. On the other hand, methanol did not affect the production of antimicrobial compounds, and organic nitrogen sources such as corn steep liquor and peptone were better than inorganic nitrogen sources. These compounds showed broad antimicrobial spectrum to the tested strains such as bacteria and yeast. The antimicrobial comounds were very stable under heat(121$^{\circ}C$), acid(pH2.0), alkali(pH11.0) treatments. These compounds were isolated by ethylacetate extract, silica gel column chromatography and reverse phase HPLC. Two compounds(peak 1 and 2) were detected as antimicrobial compounds through the HPLC analysis. The peak 2 was purified as a single compound and revealed a 98% purity.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.771-775
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• 2009

Antimicrobial activity of garlic (pH 6.0) heated at $120^{\circ}C$ reached its maximum at 45 min of heating and maintained the level for the rest of heating time (300 min) when tested against Candida utilis ATCC42416. The principal antimicrobial compound was allyl alcohol (AA), a highly volatile compound without sulfur in its molecule. The concentration of AA in heated garlic gradually increased to over 2,000 ppm for the first 90 min and stayed at the level without appreciable changes in spite of further heating. Other antimicrobial compounds secondary to AA were lowly volatile sulfur compounds including diallyl polysulfides (diallyl trisulfide, diallyl tetrasulfide, and diallyl pentasulfide) and heterocyclic sulfur compounds (4-methyl-1,2,3-trithiolane, 5-methyl-1,2,3,4-tetrathiane, and 6-methyl-1,2,3,4,5-pentathiepane). When the pH of the garlic extract was lowered before heating, considerably more secondary antimicrobial sulfur compounds were formed and the antimicrobial activity was stronger than the pH unadjusted garlic. Lowly volatile sulfur compounds contributed a significant part of antimicrobial activity of heated garlic only during the early period (45-120 min) of heating regardless of pH treatment.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2345-2350
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• 2010

A series of thiadiazole derivatives were synthesized with differently substituted benzoic acids which were cyclized to give differently substituted thiazolidin-4-one. Elemental analysis, IR, $^1H$ NMR, $^{13}C$ NMR and mass spectral data confirmed the structure of the newly synthesized compounds. The derivatives of these moieties were evaluated for antimicrobial activity. Most of the synthesized compounds showed good antimicrobial activity at 200 and $100\;{\mu}g/mL$. Compounds showed most significant antibacterial activity against gram negative test organism Escherichia coli and most significant antifungal activity against test organisms Aspergillus niger and Candida albicans. It was observed that compounds with $OCH_3$ at 3, 4 position of phenyl ring [5(a-l)] were more potent against microbes as compared to compounds having unsubstituted phenyl ring [4(a-l)].

• Archives of Pharmacal Research
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• v.8 no.1
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• pp.21-30
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• 1985

Examination of the constituents of a marine sponge, Aplysina fishtularis, indicated that brominated tyrosine metabolites were mainly responsible for antimicrobial and antineoplastic activities. Halogenated tyrosine metabolites, 2, 6-dibromo-(2), 2-bromo-3-chloro-(3) and 2, 6-dibromo-(5), 5-a mino-2-bromo-6-chloro-(6) and 5-amino-2, 6-dich-loro-(7) 4-hydroxy-2-cyclohexenone-4-acetic acid lactams were identified as the major antineoplastic and antimicrobial principles. Many other brominated tyrosine metabolites were also confirmed, but they did not show antimicrobial and antineoplastic activities.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.235-240
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• 2000

Various separation techniques of antimicrobial compounds from food materials have proven to be ineffective, involving liquid-liquid extraction and chromatography. We established efficient separation procedure for partially purifying antimicrobial compounds from Korean leek. Separation procedures consisted of ultrafiltration, liquid-liquid extraction, TLC and HPLC. Molecular weight of antimicrobial compounds were less than 5,000 dalton. Major compounds were propenyl methyl disulfide, S-methyl methylthiosulphonate and dimethyl disulfide.

• YAKHAK HOEJI
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• v.54 no.1
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• pp.22-26
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• 2010

We studied the antimicrobial activities of five compounds isolated from the stems of Vitis coignetiae Pulliat and the seeds of Perilla frutescens (L.) Britton. Based on spectroscopic evidence, compounds 1 to 5 were characterized as resveratrol, $\varepsilon$-viniferin, ampelopsin E, apigenin, and luteolin, respectively. The antimicrobial activities against Gram-positive (Staphylococcus aureus) and -negative (Pseudomonas aeruginosa) bacteria and a fungus (Candida albicans) were investigated using the disc diffusion and broth dilution methods. C. albicans was not inhibited by the five compounds. Compounds 2 and 5 had significant anti-microbial activity against S. aureus, and the 50% inhibitory concentration ($IC_{50}$) of compound 2 against S. aureus was 7.2 ${\mu}M$. Compounds 4 and 5 significantly inhibited P. aeruginosa and the minimum inhibitory concentration (MIC) of compounds 2 and 5 was 0.07 and 2.0 ${\mu}M$, respectively. Compounds 2, 4, and 5 had strong anti-microbial activity against S. aureus and P. aeruginosa.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.769-775
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• 2012

Among the phenolic compounds that is generally present in strawberry fruits, five simple phenolics, three flavonoids, and a stilbene were tested for their antimicrobial activity against seven fungi and one oomycete. trans-Cinnamic acid showed strong antimicrobial activity, and the antimicrobial effect of the simple phenolics decreased with an increase in the number of hydroxyl groups. Phytophthora capsici was the most susceptible to the phenolic compounds tested in this study. trans-Cinnamic acid, p-hydroxybenzoic acid, and kaempferol were mainly detected in 'Seolhyang' strawberry fruits, and the total phenolic contents of the fruits decreased during their development. Extracts of the green (1-10% red color) and red (above 90% red color) strawberry fruits reduced the mycelial growth and zoospore germination rate of P. capsici, and the extract of red strawberry fruit showed strong antimicrobial activity against the zoospore germination of P. capsici. These results indicate that strawberry fruits contain antimicrobial phenolic compounds and that strawberry fruit extract can be used as a natural fungistat.

• Food Science and Preservation
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• v.4 no.3
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• pp.295-300
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• 1997

The water extract of mustard seed was fractionated by solvents with an increase of polarity, and antimicrobial activities of each extracts were examined, and volatile compounds of each extract were identified by GC-MS. When the water extract was fractionated with solvents, the antimicrobial activities were high in the order of chloroform, ethylacetate, hexane, butanol and aqueous layer. In chloroform fraction, 16 volatile compounds, including 2 isothiocyanates such as 3-isothiocyanato- 1-propene and 4-isothiocyanato- 1-butane, 1 nitrile and 4 acids were identified, their contents were higher than other fractions. Twelve, 10, 4 and 7 volatile compounds were identified in ethylaceate, hexane, butanol and water fractions, respectively. The volatile compounds were considerably less in the fractions of butanol and water than others.

• Archives of Pharmacal Research
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• v.27 no.9
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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.