• Journal of the Korean Chemical Society
• /
• v.55 no.4
• /
• pp.638-643
• /
• 2011

The synthesis of biologically active 1H-1,4-diazepines 4a-d and 3H-1,5-benzodiazepines 5a-d in good yields, from the heterocyclization reaction of 2-(4-methylthio benzenesulfonyl)-1,3-dimethyl/1-methyl-3-phenyl/1,3-diphenyl/1-methyl-3-ethoxy propane-1,3-dione 3a-d with ethylenediamine (EDA) and o-phenylenediamine (o-PDA), respectively, in the presence of silica sulfuric acid (SSA) is described. The novel ${\beta}$-diketones/${\beta}$-ketoesters 3a-d were synthesized by the condensation reaction of 4-methylthiobenzenesulfonyl chloride 1 with various ${\beta}$-diketones/${\beta}$-ketoesters 2a-d. All structures of the newly synthesized compounds were elucidated by elemental analysis and spectral studies. The compounds 4a-d and 5a-d have been screened for antimicrobial, antifungal and anthelmintic activity.

• Mycobiology
• /
• v.43 no.3
• /
• pp.333-338
• /
• 2015

In a previous study, we identified a Streptomyces sp., A3265, as exhibiting potent antifungal activity against various plant pathogenic fungi, including Botrytis cinerea, Colletotrichum gloeosporioides, and Rhizoctonia solani. This strain also exhibited a biocontrolling effect against ginseng root rot and damping-off disease, common diseases of ginseng and other crops. In this study, we isolated two antifungal substances responsible for this biocontrolling effect via Diaion HP-20 and Sephadex LH-20 column chromatography, medium pressure liquid chromatography, and high-performance liquid chromatography. These compounds were identified as guanidylfungin A and methyl guanidylfungin A by spectroscopic methods. These compounds exhibited potent antimicrobial activity against various plant pathogenic fungi as well as against bacteria.

• Mycobiology
• /
• v.46 no.1
• /
• pp.52-63
• /
• 2018

In our previous studies, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15 have been shown to be antagonistic to Aspergillus flavus in stored rice grains. In this study, the biocontrol activities of these strains were evaluated against Aspergillus candidus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum, which are predominant in stored rice grains. In vitro and in vivo antifungal activities of the bacterial strains were evaluated against the fungi on media and rice grains, respectively. The antifungal activities of the volatiles produced by the strains against fungal development and population were also tested using I-plates. In in vitro tests, the strains produced secondary metabolites capable of reducing conidial germination, germ-tube elongation, and mycelial growth of all the tested fungi. In in vivo tests, the strains significantly inhibited the fungal growth in rice grains. Additionally, in I-plate tests, strains KU143 and AS15 produced volatiles that significantly inhibited not only mycelial growth, sporulation, and conidial germination of the fungi on media but also fungal populations on rice grains. GC-MS analysis of the volatiles by strains KU143 and AS15 identified 12 and 17 compounds, respectively. Among these, the antifungal compound, 5-methyl-2-phenyl-1H-indole, was produced by strain KU143 and the antimicrobial compounds, 2-butyl 1-octanal, dimethyl disulfide, 2-isopropyl-5-methyl-1-heptanol, and 4-trifluoroacetoxyhexadecane, were produced by strain AS15. These results suggest that the tested strains producing extracellular metabolites and/or volatiles may have a broad spectrum of antifungal activities against the grain fungi. In particular, B. megaterium KU143 and P. protegens AS15 may be potential biocontrol agents against Aspergillus and Penicillium spp. during rice grain storage.

• Journal of Pharmacopuncture
• /
• v.19 no.3
• /
• pp.246-252
• /
• 2016

Objectives: The purpose of this study was to obtain a natural antibiotic from Phenol-rich compounds; for the dressing and the treatment of chronic wounds. Methods: The Phenol-rich compound sweet gel was prepared by blending four natural herbal extracts, Acacia catechu (L.F.), Momia (Shilajit), Castanea sativa, and Ephedra sinica stapf, with combination of a sweet gel medium, including honey, maple saps, Phoenix dactylifera L. (date), pomegranate extract and Azadirachta indica gum as a stabilizer. The combinations were screened by using a well-diffusion assay with cloxacillin as a control. Pseudomonas spp. was tested with our novel antimicrobial compound. The zones of inhibition in agar culture were measured for each individual component and for the compound, and the results were compared with those of the control group which had been treated with cloxacillin. Data were expressed as means ${\pm}$ standard deviations. Quantitative analyses were performed using the paired t-test. Results: The antibiotic effect of the Phenol-rich compound sweet gel was statistically shown to be more significant than that of cloxacillin against Pseudomonas aeruginosa (P < 0.05). Conclusion: Our novel approach to fighting the antibiotic resistance of Pseudomonas proved to be successful. The Phenol-rich compound sweet gel was found to be suitable for use as an alternative medicine and bioactive dressing material, for the treatment of patients with various types of wounds, including burns, venous leg ulcers, ulcers of various etiologies, leg ulcers on the feet of diabetic, unhealed graft sampling sites, abscesses, boils, surgical wounds, necrotic process, post-operative and neonatal wound infection, and should be considered as an alternative to the usual methods of cure.

• Applied Biological Chemistry
• /
• v.39 no.5
• /
• pp.409-413
• /
• 1996

To search for bioactive compounds from plant resources, 80% methanol extracts of 46 species of weeds were screened for their activities of antimicrobial, antioxidative, antiblebing, antitumor and herbicidal. Among extracts tested, some showed activities at the concentration of $50\;to\;100\;{\mu}g/ml$. Phryma leptostachya var. asiatica, Aster ageratoides, Centipeda minima, Cirsium pendulum, Lythrum anceps showed antibacterial activity. Penthorum chinense, Lindernia procumbens, Aster ageratoides, Dianthus superbus var. longicalycinus showed antiblebing activity. Phyma leptostachya var. asiatica, Juncus effusus var. decipiens, Lindernia procumbens, Aster ageratoides, Dianthus superbus var. longicalycinus, Viscum album var. coloratum showed antitumor activity. Juncus effusus var. decipiens, Hypericum ascyron, Juncus papillosus, Inula britannicar var. chinensis, Scirpus wichurae, Hypericum laxum showed antioxidant activity.

• The Plant Pathology Journal
• /
• v.36 no.6
• /
• pp.515-535
• /
• 2020

Essential oils (EOs) have gained a renewed interest in many disciplines such as plant disease control and medicine. This review discusses the components of ginger EOs, their mode of action, and their potential nanotechnology applications in controlling tropical plant diseases. Gas chromatography-mass spectroscopy (GC-MS), high-performance liquid chromatography, and headspace procedures are commonly used to detect and profile their chemical compositions EOs in ginger. The ginger EOs are composed of monoterpenes (transcaryophyllene, camphene, geranial, eucalyptol, and neral) and sesquiterpene hydrocarbons (α-zingiberene, ar-curcumene, β-bisabolene, and β-sesquiphellandrene). GC-MS analysis of the EOs revealed many compounds but few compounds were revealed using the headspace approach. The EOs have a wide range of activities against many phytopathogens. EOs mode of action affects both the pathogen cell's external envelope and internal structures. The problems associated with solubility and stability of EOs had prompted the use nanotechnology such as nanoemulsions. The use of nanoemulsion to increase efficiency and supply of EOs to control plant diseases control was discussed in this present paper. The findings of this review paper may accelerate the effective use of ginger EOs in controlling tropical plant diseases.

• Korean Journal of Food Science and Technology
• /
• v.38 no.5
• /
• pp.699-706
• /
• 2006

The antioxidative and antimicrobial activities of Euphorbia jolkini extracts were investigated. Total polyphenohc compounds extracted were approximately as follows: 162.08 mg/g from ethanol, 12.64 mg/g from n-hexane, 48.11 mg/g from dichloromethane, 544.08 mg/g from ethyl acetate, 176.42 mg/g from butanol, and 30.00 mg/g from water. The ethylacetate fraction of this extraction showed the highest antioxidative activity $(IC_{50})$: DPPH radical scavenging capacity was measured at $8.38\;{\mu}g/mL$, xanthine oxidase inhibitory activity was $466.01\;{\mu}g/mL$, superoxide radical scavenging capacity was $11.39\;{\mu}g/mL$, and nitric oxide scavenging capacity was $332.11\;{\mu}g/mL$. Antimicrobial activities were determined by paper disc method and minimum inhibitory concentration of E. jolkini extracts against food-borne pathogens and spoilage bacteria. The growth inhibition curves of E. jolkini extracts against Bacillus cereus, Listeria monocytogenes, and Escherichia coli were also determined. These results suggest that the ethylacetate fraction of E. jolkini has strong antimicrobial activity against the all species of microorganisms as well as strong antioxidant activity.

• Archives of Pharmacal Research
• /
• v.16 no.1
• /
• pp.6-12
• /
• 1993

To evaluate KR-10876, a new fluoroquinolone antibacterial agent, its effects on the central nervous system(CNS) were investigated in mmice as part of phamacological study, and the results were compared with those for ciprofloxacin and ofloxacin, two prototypes of quinolone antiabctrial agents. All the parameters indicative of CNS function and acute toxicity were measured by close observation of the animals at regular time intervals after oral treatment of test compounds. KR-10876 did not have any effect on the parameters measured at lower does (100, 300 mg/kg, p.o.), it caused ptosis, suppressed spontaneous locomotor activity, hypothemia, and prolonged hexobarbital-induced sleeping time. KR-10876 also had a slight effect on motor coordination only at high dose. Simialr to ciprofloxacin, KR-10876 did not protect mice from pentylenetetrazol-strychnine-, and electroshock-inducedl convulsions at doses tested. These findings demonstrate that KR-10876 affects CNS functions only at high doses. The rank order for effects is ofloxacin$\le$KR-10876>ciprofloxacin.

• Mycobiology
• /
• v.36 no.2
• /
• pp.93-98
• /
• 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.

• The Journal of Korean Medicine
• /
• v.25 no.4
• /
• pp.121-128
• /
• 2004

Objective : The aim of this work is to investigate the antibacterial activity of the essential oil obtained from Artemisia capillaris (A. capillaris), as the development of microbial resistance to antibiotics make it necessary to constantly look for new and active compounds effective against pathogenic bacteria. Methods : The crushed materials of A. capillaris (1 kg) were subjected to steam distillation for 3 h, using a modified Clevenger type apparatus in order to obtain essential oil. Diethyl ether was the extracting solvent kept at 25°.... The essential oil was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The essential oil and the composition were tested for antimicrobial activities against 15 different genera of oral bacteria. Results and Conclusion : The components of the essential oil identified were: β-pinene (9.36%), camphor (3.32%), 1,8­cineole (4.38%), artemisia alcohol (3.32%), β-caryophyllene (11.08%), γ-cadinene (4.23%), and capillene (32.74%). The essential oil of A. capillaris exhibited considerable inhibitory effects against all oral bacteria tested, while their major components demonstrated various degrees of growth inhibition.