• Title/Summary/Keyword: Antagonistic Activity

Search Result 434, Processing Time 0.028 seconds

Purification and characterization of antifungal compounds produced by Bacillus subtilis KS1 (Bacillus subtilis KS1이 생산하는 항진균물질의 정제 및 특성)

  • Ryoo, Sung-Woo;Maeng, Hack-Young;Maeng, Pil-Jae
    • The Korean Journal of Mycology
    • /
    • v.24 no.4 s.79
    • /
    • pp.293-304
    • /
    • 1996
  • A bacterial strain, KSl, possessing strong antifungal activity was isolated from soil samples of ginseng fields and identified as Bacillus subtilis. In greenhouse test, the culture filtrate of B. subtilis KS1 showed strong protective effect against several fungal diseases of agricultural plants such as cucumber gray mold and wheat leaf rust. In addition, the crude butanol fraction of the culture filtrate exhibited antagonistic effect against several fungi including plant or human pathogens, such as Botrytis maydis, Chytridium lagenarium and Candida albicans. The antifungal compound, SW1, produced by B. subtilis KS1 was purified through consecutive chromatographic separations on a pep-RPC column and a ${\mu}$ Bondapak $C_{18}$ reverse phase column. Temperature and pH showed little effect on the stability of the compound in the ranges $-20-121^{\circ}C$ and pH 4.0-10.0, respectively. The composition and structural characteristics of SW1 were analysed by HPLC and by $^1H-,\;^1H-^1H-COSY$, NOESY, COSY-NOESY and HOHAHA NMR spectroscopy, respectively, which revealed that the compound belongs to iturin A, a typical cyclic antifungal compound produced by B. subtilis. In contrast to the previously reported iturin A compounds which have one or no $-CH_3$ side chain in the hydrophobic hydrocarbon chain of ${\beta}-amino$ acids, SW1 was shown to have a ${\beta}-amino$ acid containing 12-carbon skeleton with two $-CH_3$ side chains.

  • PDF

Selection of Acid-tolerant and Hetero-fermentative Lactic Acid Bacteria Producing Non-proteinaceous Anti-bacterial Substances for Kimchi Fermentation (비단백질성 항균물질을 생산하는 김치발효용 내산성 Hetero 발효형 유산균주 선발)

  • Kim, Hye-Rim;Lee, Jong-Hoon
    • Microbiology and Biotechnology Letters
    • /
    • v.41 no.1
    • /
    • pp.119-127
    • /
    • 2013
  • Twenty-three strains of Leuconostoc species and 45 strains of Weissella species inhibiting the growth of Lactobacillus sakei, one of the most populous lactic acid bacteria in over-ripened kimchi, were isolated from kimchi in our previous study. Among these hetero-fermentative 68 strains, Leuconostoc mesenteroides CK0128, Weissella cibaria CK0633, and W. cibaria KK0797 exhibited a relatively high survival rate in MRS medium, which was adjusted to pH 4.3 using an acid mixture consisting of acetic and lactic acids, and produced a large amount of exopolysaccharides. The culture supernatants of 3 strains were fractionated by a molecular weight cutter and lyophilized. The fractions with a molecular weight smaller than 3,000 Da showed antagonistic activity against Staphylococcus aureus and Lb. sakei. The anti-bacterial substances were very stable to heat treatments ($121^{\circ}C$, 15 min) and active at acidic conditions below pH 5. ${\alpha}$-Amylase, lipase, and proteolytic enzymes (proteinase K and pepsin) did not affect their activities. These non-proteinaceous anti-bacterial substances inhibited the growth of several food pathogens.

Suppression Effect of Gray Mold and Late Blight on Tomato Plants by Rhamnolipid B (Rhamnolipid B에 의한 토마토 잿빛곰팡이병과 역병의 억제효과)

  • Ahn, Ji-Ye;Park, Myung-Soo;Kim, Seul-Ki;Choi, Gyung-Ja;Jang, Kyoung-Soo;Choi, Yong-Ho;Choi, Jae-Eul;Kim, In-Seon;Kim, Jin-Cheol
    • Research in Plant Disease
    • /
    • v.15 no.3
    • /
    • pp.222-229
    • /
    • 2009
  • A Pseudomonas strain SG3 producing biosurfactant and showing antifungal and insecticidal activities was isolated from agricultural soil severely contaminated with machine oils. The antagonistic bacterium inhibited mycelial growth of all of the tested fungal pathogens. The fermentation broth of SG3 also effectively suppressed the development of various plant diseases including rice blast, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose. An antifungal substance was isolated from the fermentation broth of SG3 by ethyl acetate partitioning, silica gel column chromatography and preparative HPLC under the guide of bioassay. The chemical structure of the antifungal substance was determined to be rhamnolipid B by mass and NMR spectral analyses. The antifungal biosurfactant showed a potent in vivo antifungal activity against gray mold and late blight on tomato plants. In addition, rhamnolipid B inhibited mycelial growth of B. cinerea causing tomato gray mold and zoospore germination and mycelial growth of P. infestans causing tomato late blight. Pseudomonas sp. SG3 producing rhamnolipid B could be used as a new biocontrol agent for the control of plant diseases occurring on tomato plants.

Development of Biofungicide Using Bacillus sp. KBC1004 for the Control of Anthracnose of Red Pepper (길항세균 Bacillus sp. KBC1004를 이용한 고추탄저병의 생물학적 방제제 개발)

  • Kang, Hoon-Serg;Kang, Jae-Gon;Park, Jeong-Chan;Lee, Young-Ui;Jeong, Yoon-Woo;Kim, Jeong-Jun;Park, Chang-Seuk
    • Research in Plant Disease
    • /
    • v.21 no.3
    • /
    • pp.208-214
    • /
    • 2015
  • To develop an effective biopesticide to control pepper anthracnose disease, an isolate which showed strong inhibitory effect on the mycelial growth and conidial germination of Colletotrichum acutatum was selected among the antagonistic bacterial isolates collected from pepper grown soil. The bacterial isolate was identified as Bacillus sp. KBC1004 using 16S rRNA sequence analysis. The liquid culture of KBC1004 was freeze-dried and formulated as a wettable powder(WP). The wettable powder form of KBC1004 required at least 24 hours to activate and to inhibit the conidial germination of C. acutatum. In vitro bioassay using the detached green pepper fruits, biocontrol activity of the WP was not recognizable in simultaneous inoculation, but significant disease suppression was observed pre-treatment (24 hr) of the WP before pathogen inoculation. In field experiment, 4 times foliar applications of the 1/500 diluted wettable powder from the end of June showed great control efficacy similar to that of the chemical fungicide application. These results suggest that the formulated WP product could be an alternative mean to control of pepper anthracnose disease in environmentally friendly farming practices.

The Effect of female Hormone on Knee Joint Laxity (여성 호르몬이 무릎의 느슨함(laxity)에 미치는 영향)

  • Park, Sang-Kyoon
    • Korean Journal of Applied Biomechanics
    • /
    • v.19 no.1
    • /
    • pp.99-106
    • /
    • 2009
  • The purpose of this study was to determine whether hormone levels change knee laxity in healthy females. Twenty three healthy females were recruited for the study. Serum estradiol and progesterone levels were recorded three times during the subjects' menstrual cycles. The first measurements were taken between day 3 and 7 of the follicular phase and the second data collection coincided with ovulation, 24 to 48 hours after the estrogen surge detected by an ovulation predictor kits. Based on a 28 day cycle, the third data collection occurred approximately 7 days later during the luteal phase. Knee joint laxity was recorded at the same intervals with a KT 2000 arthometer. Hormone levels and phases were compared to passive knee joint laxity with multiple regression analysis. Estradiol and progesterone levels differed significantly across the three tests. Knee joint laxity increased during ovulation. Based on a multiple regression analysis, estradiol and progesterone levels predicts 77.9% to 80.9% of the laxity at 20lb and 30lb loads. An antagonistic relationship between estradiol and progesterone was found when testing for knee laxity. Serum hormone levels have moderate power in predicting knee joint laxity. Individual hormonal profiling in female athletes would allow researchers to access the structural properties of the ACL, such as the laxity which may provide beneficial information to understand female ACL injury mechanism in sports activity.

Medetomidine Sedation and Its Antagonism by Yohimbine in Dogs (개에서 Medetomidine 진정에 대한 Yohimbine의 길항작용)

  • Heo, Keong-Hee;Lee, Jae-Yeon;Choi, Kyeong-Ha;Cho, Jin-Haeng;Park, Chang-Sik;Kim, Myung-Cheol
    • Journal of Veterinary Clinics
    • /
    • v.27 no.4
    • /
    • pp.343-347
    • /
    • 2010
  • The purpose of this study was to determine the antagonistic effects of yohimbine on sedation induced in dogs with medetomidine. Six mixed breed dogs were repeatedly used at a 2 weeks withdrawal time in this study. The dogs received $40\;{\mu}g/kg$ of medetomidine followed 15 minutes later by 0.2 ml/kg saline solution (group M) or 0.11 mg/kg yohimbine (group MY). All the dogs were examined before and 5, 15, 30, 45, 60, 75, 90, 120 and 150 minutes after the injection of medetomidine, and the induction and recovery times, vital signs, blood biochemistry and anesthetic quality were recorded. There were significant differences in the recovery of anesthesia between the groups. In both groups the heart rate decreased rapidly down to five minutes after the administration of medetomidine. The activity of ALT, AST and the protein concentration did not change significantly in either group and there was no significant difference between them at any time. Response to noise, muscle tone and analgesic score in the MY group at 30 minutes were significantly lower than those of the M group. When recovering from anesthesia, the dogs treated with yohimbine took less time to achieve sternal recumbency and less time to be able to stand and walk. It was concluded that yohimbine reversed effectively medetomidine sedation in dogs.

Anti-thrombic Properties of the Oriental Herbal Medicine, Daejowhan

  • Chang Gyu-Tae;Kim Jang-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.19 no.5
    • /
    • pp.1391-1398
    • /
    • 2005
  • The anti-thrombic properties of the oriental herbal medicine Daejowhan(DJW, 大造丸) which consists of 11 kinds of herbs (indicated as ratio) of Rehmanniae Radix 24%, Hominis Placenta 5%, Testudinis Carapax 9%, Eucommiae Cortex 9%, Asparagi Radix 9%, Phellodendri Cortex 9%, Achyranthis Radix 7%, Liriopis Tuber 7%, Angelicae Sinensis Radix 7%, Ginseng Radix 5% and Schizandrae Fructus 3% were investigated. The water extracts from DJW inhibited Platelet-activating factor(PAF) induced platelet aggregation. DJW was extracted with methanol and further fractionated by ethylacetate. A 70% methanol extract showed a strong inhibition against PAF-induced aggregation in vitro and in vivo assays. The ethylacetate soluble fraction was shown to have inhibitory effect on PAF-induced platelet aggregation in vitro assay. The ethylacetate soluble fraction specially protected against the lethality of PAF, while verapamil did not afford any protection. These results indicate that the water extracts and alcoholic-fractions inhibit the action of PAF in vivo by an antagonistic effect on PAF, so that it may be useful in treating disorders caused by PAF, such as acute allergy, inflammation, asthma, gastrointestinal ulceration, toxic shock and so forth. DJW was investigated regarding its assumed anti-thrombic action on human platelets which was deduced from its ability to suppress Arachidonic acid(AA)-induced aggregation, exocytosis of ATP, and inhibition of Cyclooxygenase(COX) and Thromboxane synthase(TXS) activity. The latter two effects were estimated from the generation of Prostaglandin $E_2(PGE_2)$ and Thromboxane $A_2(TXA_2)$ respectively. Exogenously applied AA ($100{\mu}mol/{\ell}$) provoked a $89\%$ aggregation of platelets, the release of 14 pmol ATP, and the formation of either 225 pg $TXA_2$ or 45 pg $PGE_2$, each parameter being related to 106 platelets. An application of DJW 5 min before AA dose-dependently diminished aggregation, ATP-release and the synthesis of $TXA_2$ and $PGE_2$ with $IC_{50}$ values of 74, 108, 65, $72{\mu}g/m{\ell}$, respectively. The similarity of the $IC_{50}$ values suggest an inhibition of COX by DJW as primary target, thus suppressing the generation of $TXA_2$ which induces aggregation of platelets and exocytosis of ATP by its binding on $TXA_2$-receptors.

Schedule-Dependent Effect of Epigallocatechin-3-Gallate (EGCG) with Paclitaxel on H460 Cells

  • Park, Sunghoon;Kim, Joo-Hee;Hwang, Yong Il;Jung, Ki-Suck;Jang, Young Sook;Jang, Seung Hun
    • Tuberculosis and Respiratory Diseases
    • /
    • v.76 no.3
    • /
    • pp.114-119
    • /
    • 2014
  • Background: Epigallocatechin-3-gallate (EGCG), a major biologically active component of green tea, has anti-cancer activity in human and animal models. We investigated the schedule-dependent effect of EGCG and paclitaxel on growth of NCI-H460 non-small cell lung cancer cells. Methods: To investigate the combined effect of EGCG (E) and paclitaxel (P), combination indices (CIs) were calculated, and cell cycle analysis was performed. For the effect on cell apoptosis, western blot analysis was also performed. Results: CI analysis demonstrated that both concurrent and sequential E ${\rightarrow}$ P treatments had antagonistic effects (CIs >1.0), but sequential P ${\rightarrow}$ E had synergistic effects (CIs <1.0), on the growth inhibition of NCI-H460 cells. In the cell cycle analysis, although paclitaxel induced $G_2/M$ cell cycle arrest and increased the sub-G1 fraction, concurrent EGCG and paclitaxel treatments did not have any additive or synergistic effects compared with the paclitaxel treatment alone. However, western blot analysis demonstrated that sequential P ${\rightarrow}$ E treatment decreased the expression of Bcl-2 and procaspase-3 and increased poly(ADP-ribose) polymerase (PARP) cleavage; while minimal effects were seen with concurrent or sequential E ${\rightarrow}$ P treatments. Conclusion: Concurrent or sequential E ${\rightarrow}$ P treatment had opposite effects to P ${\rightarrow}$ E treatment, where P ${\rightarrow}$ E treatment showed a synergistic effect on growth inhibition of NCI-H460 cells by inducing apoptosis. Thus, the efficacy of EGCG and paclitaxel combination treatment seems to be schedule-dependent.

Purification and Characterization of an Antimicrobial Substance from Bacillus subtilis HH28 Antagonistic to Bacillus cereus (Bacillus cereus를 억제하는 Bacillus subtilis HH28의 항균물질 정제와 특성규명)

  • Cha, Hyun A;Chung, Dawn;Hong, Sung Wook;Chung, Kun Sub
    • Microbiology and Biotechnology Letters
    • /
    • v.42 no.4
    • /
    • pp.393-401
    • /
    • 2014
  • A bacterium producing antimicrobial substance was isolated from cheonggukjang. The bacterium was identified as a strain of Bacillus subtilis by 16S rDNA sequencing and designated as Bacillus subtilis HH28. The antimicrobial substance produced from Bacillus subtilis HH28 was purified by 0-80% ammonium sulfate precipitation, DEAE-sepharose FF column chromatography, and Sephacryl S-200 HR gel chromatography. The molecular weight of the purified antimicrobial substance was estimated to be approximately 3,500 Da using Tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis and direct detection analysis. Antimicrobial substance from B. subtilis HH28 not only inhibited B. cereus, but also Listeria monocytogenes and Vibrio parahaemolyticus. The purified antimicrobial substance was stable at $40-80^{\circ}C$, and between pH 2 and 8. Antimicrobial activity of the purified substance was completely destroyed by treatment of protease, proteinase K, and pronase E, indicating that it is proteinaceous.

Pharmacological Characterization of (10bS)-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline Oxalate (YSL-3S) as a New ${\alpha}_2$-Adrenoceptor Antagonist

  • Chung, Sung-Hyun;Yook, Ju-Won;Min, Byung-Jun;Lee, Jae-Yeol;Lee, Yong-Sup;Jin, Chang-Bae
    • Archives of Pharmacal Research
    • /
    • v.23 no.4
    • /
    • pp.353-359
    • /
    • 2000
  • ${\alpha}_2$-Adrenoceptor antagonists, which can enhance synaptic norepinephrine levels by blocking feedback inhibition processes, are potentially useful in the treatment of disease states such. as depression, memory impairment, impotence and sexual dysfunction. (10bS)-1,2,3,5,6,10b-Hexahydropyrrolo[2,1-a]isoquinoline oxalate (YSL-3S) was evaluated in several in vitro biological tests to establish its pharmacological profile of activities as an ${\alpha}_2$-adrenoceptor antagonist. Saturation binding assay revealed that$^{3}[H]$rauwolscine bound to the $\alpha$$_2$-adrenoceptors with a Kd value of 6.3$\pm$0.5 nM and a Bmax value of 25l$\pm$39 fmol/mg protein in rat cortical synaptic membranes. Competitive binding assay showed that YSL-3S inhibited the binding of$^3[H]$rauwolscine (1 nM) in a concentration-dependent manner with a Ki value of 98.2$\pm$12.1 nM while it did not inhibit the binding of [$^3$H]cytisine (1.25 nM) to neuronal nicotinic cholinergic receptors. The Ki values of yohimbine, clonidine and norepinephrine for $^3[H]$rauwolscine binding were 15.8$\pm$1.0, 40.1$\pm$5.9 and 40.0$\pm$11.5 nM, respectively. In addition, the binding affinity of YSL-3S for ${\alpha}_2$-adrenoceptors was higher than that of its antipode and the racemic mixture. The functional activity of YSL-3S at the presynaptic ${\alpha}_2$-adrenoceptors was assessed using the prostatic portion of the rat vas deferens. Clonidine inhibited field-stimulated contractions of the vas deference in a dose-dependent manner. The presence of YSL-3S or yohimbine caused a parallel, rightward the dose-response curve of clonidine in a dose-dependent manner, indicating an antagonistic action at the presynaptic ${\alpha}_2$-adrenoceptors. The $pA_2$values of yohimbine and YSL-3S were 7.66$\pm$0.13 and 6.64$\pm$0.18, respectively. The results indicate that YSL-3S acts as a competitive antagonist at presynaptic ${\alpha}_2$ -adrenoceptors with a potency approximately ten times lower than yohimbine, but is devoid of binding affinity for neuronal nicotinic cholinergic receptors.

  • PDF