• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4854-4862
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• 2010

Twenty five compounds isopropylmethylphenyl benzenesulfonate derivatives of thymol (1), 4-isopropyl-3-methylphenol (2), 5-isopropyl-3-methylphenol (3), 4-isopropylphenol (4), and 2-isopropylphenol (5) derivatives were synthesized. These compounds were analyzed for their structural confirmation with IR, GC/MS, and $^1H$-NMR. Synthetic compounds were tested against phytopathogenic fungi activities such as Pyrcularia grisea, Rhizoctonia solani, Phytophthora infestans, Colletotrichum orbiculare, and Sphaerotheca fusca. 2-Isopropyl-5-methylphenyl o-toluenesulfonate (1a), 2-isopropylphenyl 2,4,5-trichloro-benzenesulfonate (5b) and 2-isopropylphenyl 2-methyl-5-nitrobenzenesulfonate (5e) showed a potent in vivo antifungal activity against Pyrcularia grisea, Phytophthora infestans and Sphaerotheca fusca.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.31-37
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• 1990

To obtain the values of linear stability derivatives, both analytical and experimental methods are now proposed and in use. The experimental method is well known as the planar motion mechanism(PMM) test. Its concept is to drive the model with a prescrived frequency and amplitude of the motion and pick up the hydrodynamic forces. But this kind of method is inconvenient in case we want to know the stability derivatives in wider range of the frequencies. So a different method is attempted that with one test run, we can get the derivatives in wider range of the frequencies. This technique forces the impulsive motion on the model, using the power of the oil pressure pump. This kind of method was originated by Scragg, C.A., Cummins, W.E, or Frank, T., This resarch is a further development of such preceding works. Todd's series 60(Cb=0.7) 2.00M model is chosen for the test and the results are compared with Van Leeuwen's famous PMM test results.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.840-847
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• 2010

In this study, we identified the volatile compounds of Artemisia princeps Pampan. cv. ssajuari (ssajuarissuk) essential oils and analyzed changes in the contents of volatile compounds under four different storage conditions, such as exposure to air at $20^{\circ}C$ and $40^{\circ}C$. Sixty-five volatile compounds consisting of 6 monoterpene hydrocarbons, 23 oxygenated monoterpenes, 16 sesquiterpene hydrocarbons, 6 oxygenated sesquiterpenes, 1 diterpene, 6 benzene derivatives, and 7 non-isoprenoid compounds were identified on the basis of their mass spectra characteristics and retention indices from original ssajuarissuk essential oils. Identified compounds constituted 90.56% of the total peak area. Borneol (10.29%) was the most abundant compound in the original ssajuarissuk essential oils, followed by 1,8-cineole (9.06%), viridiflorol (8.99%), spathulenol (8.73%), $\alpha$-thujone (5.28%), and camphor (4.39%). After six months storage at $40^{\circ}C$ with the cap opened for 3 min everyday, the total amount of volatile compounds in essential oil as determined by the percentage peak area decreased by 84.93%. The total levels of cis-sabinene hydrate, camphor, 4-terpineol, humulene oxide, $\beta$-caryophyllene oxide, and caryophyllene alcohol increased significantly. For ssajuarissuk essential oils stored under experimental conditions, changes in the contents of volatile compounds in essential oils were accelerated by temperature and contact with the atmosphere.

• Journal of ILASS-Korea
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• v.14 no.2
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• pp.49-58
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• 2009

Non-edible vegetable oils instead of edible vegetable oils as a substitute for diesel fuel are getting a renewed attention because of global reduction of green house gases and concerns for long-term food and energy security. Out of various non-edible vegetable oils, karanja, mahua, linseed, rubber seed and cotton seed oils are selected in this study. A brief review of recent works related to the application of the above five vegetable oils and its derivatives in CI engines is presented. The production technologies of biodiesel based on non-edible vegetable oils are introduced. Problems in vegetable oil or biodiesel fuelled CI engine are included. In addition, future works related to spray characteristics of non-edible vegetable oil or biodiesel from it are discussed. The biodiesel fuel, irrespective of the feedstock used, results in a decrease in the emission of hydrocardon (HC), carbon monoxide (CO), particulate matter (PM) and sulphur dioxide ($SO_2$). It is also said to be carbon neutral as it contributes no net carbon dioxide to the atmosphere. Only oxides of nitrogen (NOx) are reported to increase which is due to oxygen content in the biodiesel fuel. The systematic assessment of spray char-acteristics of neat vegetable oils and its blends, neat biodiesel and its blends f3r use as diesel engine fuels is required.

• Journal of the Korean Applied Science and Technology
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• v.19 no.3
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• pp.222-244
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• 2002

A mixture of methyl ester derivatives of fatty acids from the oils of pine nuts was well resolved to five fractions differing by degree of unsaturation by silver ion solid-phase extraction column chromatography ($Ag^{+}$-SEC). Polyunsaturated fatty acid with non-methylene interrupted conjugated double bond (NMiDB) radical held more strongly to silver ions in the column than methylene interrupted conjugated double bond (MiDB) one when they had the same number of double bonds. Although both the picolinyl ester and DMOX derivative provided clear mass ion species powerful enough to elucidate the structure of the polyunsaturated fatty acid (PUFA) with NMiDB and/or methylene interrupted conjugated double bond (MiDB) radical in the oils, the picolinyl ester of PUFA with NMiDB radical did not provide a cluster of mass ions neighboring diagnostic mass ions induced by the double bond in the proximal to the carboxyl group. However, the DMOX derivative of PUFA with NMiDB group as well as MiDB showed abundant mass ion species differing by gaps of 12 amu, which made it possible with greater ease to locate the double bonds in the molecule. The oil contained $C_{18:2{\omega}6}$ (46.2 %) and $C_{18:1{\omega}9}$ (25.4 %) as main components, and considerable amounts of PUFAs with NMiDB radical such as ${\Delta}^{5.\;9.\;12}-C_{18:3}$ (16.0 %), ${\Delta}^{5.\;9}-C_{18:2}$ (2.3 %) and ${\Delta}^{5.\;11.\;14}-C_{20:3}$ (0.8 %).

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.441-451
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• 2016

Squalene is a linear triterpene formed via the MVA or MEP biosynthetic pathway and is widely distributed in bacteria, fungi, algae, plants, and animals. Metabolically, squalene is used not only as a precursor in the synthesis of complex secondary metabolites such as sterols, hormones, and vitamins, but also as a carbon source in aerobic and anaerobic fermentation in microorganisms. Owing to the increasing roles of squalene as an antioxidant, anticancer, and anti-inflammatory agent, the demand for this chemical is highly urgent. As a result, with the exception of traditional methods of the isolation of squalene from animals (shark liver oil) and plants, biotechnological methods using microorganisms as producers have afforded increased yield and productivity, but a reduction in progress. In this paper, we first review the biosynthetic routes of squalene and its typical derivatives, particularly the squalene synthase route. Second, typical biotechnological methods for the enhanced production of squalene using microbial cell factories are summarized and classified. Finally, the outline and discussion of the novel trend in the production of squalene with several updated events to 2015 are presented.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.25-28
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• 1993

Our previous report demonstrated that certain flavonoid aglycones such as apigenin (flavone), quercetin, morin (flavonols), and biochanin A (isoflavone) showed in vivo antiinflammatory activity via topical and oral routes of adminstation. As a continual study, the various flavonoid glycosides have been evaluated in mouse ear edema assay using archidonic acid or croton-oil as a inflammagen. Flavonoids were orally administered (2 mg/mouse) and ear edema inhibition was measured. Significant antiinflammatory activities were found esepcially in flavone and flavonol glycosides (15-29% inhibition) although the flavonoid derivatives tested showed less antiinflammatory activity than hydrocortisone or indomethacin. Chalcone and flavanone derivatives were not significantly active. And in general, flavonol glycosides of kaempferol-type were found to have a higher oral antiinflammatory activity than that of flavonol glycosides of quercetin-type in mice.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.473-482
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• 2013

The desulfurization ability of Sphingomonas subarctica T7b was evaluated using resting and immobilized cells with dibenzothiophene (DBT), alkyl DBTs, and commercial light gas oil (LGO) as the substrates. The resting cells of S. subarctica T7b degraded 239.2 mg of the initial 250 mg of DBT/l (1.36 mM) within 24 h at $27^{\circ}C$, while 127.5 mg of 2-hydroxybiphenyl (2-HBP)/l (0.75 mM) was formed, representing a 55% conversion of the DBT. The DBT desulfurization activity was significantly affected by the aqueous-to-oil phase ratio. In addition, the resting cells of S. subarctica T7b were able to desulfurize alkyl DBTs with long alkyl chains, although the desulfurization rate decreased with an increase in the total carbon number of the alkylated DBTs. LGO with a total sulfur content of 280 mg/l was desulfurized to 152 mg/l after 24 h of reaction. Cells immobilized by entrapment with polyvinyl alcohol (PVA) exhibited a high DBT desulfurization activity, including repeated use for more than 8 batch cycles without loss of biodesulfurization activity. The stability of the immobilized cells was better than that of the resting cells at different initial pHs, higher temperatures, and for DBT biodesulfurization in successive degradation cycles. The immobilized cells were also easily separated from the oil and water phases, giving this method great potential for oil biodesulfurization.

• Archives of Pharmacal Research
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• v.27 no.8
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• pp.878-883
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• 2004

Tacrolimus (FK506), which is isolated from Streptomyces tsukubaensis, is a new potent immu-nosuppressant. Because of poor solubility in water, the conventional intravenous dosage forms of tacrolimus contain surfactants such as cremophor EL (BASF Wyandotte Co.) or hydroge-nated polyoxy 60 castor oil (HCO-60) which may cause adverse effects. This study relates to a polymer-tacrolimus conjugate, which can be dissolved in water, formed by chemically binding the sparingly soluble drug, tacrolimus, with the water soluble polymer, methoxypoly(ethylene glycol) (mPEG). Water soluble tacrolimus-mPEG conjugates have been synthesized and shown to be function in vitro as prodrugs. These conjugates are in the form of an ester wherein the 24-, 32- or 24,32-positions are esterified. The desired 24-, 32- or 24,32-esterified com-pounds were obtained by initially acylating of tacrolimus with iodoacetic acid at the 24-,32-, or 24,32-positions and then reacting the resulting acylated tacrolimus with a mPEG in the pres-ence of a base such as sodium bicarbonate. These conjugates were converted again into tac-rolimus by the action of enzymes in human liver homogenate, and the half-lives of the conjugates are approximately 10 min in the homogenate, indicating that the esterified tacroli-mus derivatives may be practically applicable as a prod rug for the immunosuppressant.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.730-739
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) causes severe infections and poses a global healthcare challenge. The utilization of novel molecules which confer synergistical effects to existing MRSA-directed antibiotics is one of the well-accepted strategies in lieu of de novo development of new antibiotics. Thymol is a key component of the essential oil of plants in the Thymus and Origanum genera. Despite the absence of antimicrobial potency, thymol is known to inhibit MRSA biofilm formation. However, the anti-MRSA activity of thymol analogs is not well characterized. Here, we assessed the antimicrobial activity of several thymol derivatives and found that 4-chloro-2-isopropyl-5-methylphenol (chlorothymol) has antimicrobial activity against MRSA and in addition it also prevents biofilm formation. Chlorothymol inhibited staphyloxanthin production, slowed MRSA motility, and altered bacterial cell density and size. This compound also showed a synergistic antimicrobial activity with oxacillin against highly resistant S. aureus clinical isolates and biofilms associated with these isolates. Our results demonstrate that chlorinated thymol derivatives should be considered as a new lead compound in anti-MRSA therapeutics.