• Journal of Microbiology and Biotechnology
• /
• v.9 no.5
• /
• pp.572-575
• /
• 1999

Miconazole was estimated to have a minimum inhibitory concentration of 0.78 ㎍/㎖ against the methicillin-resistant strains of Staphylococcus aureus (MRSA). The antibacterial activity of miconazole against MRSA was bacteriostatic in cation-adjusted Mueller-Hinton broth, but bacteriocidal in saline solution. The anti-MRSA activity of miconazole did not show a significant change under the susceptibility-testing conditions such as various inoculum sizes, pHs, or cations (Ca/sup ++/ or Mg/sup ++/) which was added to the medium. However, the anti-MRSA activity of miconazole was completely suppressed by lipophilic a-tocopherol (50 ㎍/㎖), but definitely not by water-soluble ascorbic acid.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.3
• /
• pp.484-490
• /
• 1996

Physicochemical changes were determined for the boiled-dried anchovies packaged in a laminated film(nylon 15${\mu}{\textrm}{m}$/polyethylene 100${\mu}{\textrm}{m}$) and stored for one year at ambient and cooling(5~1$0^{\circ}C$) temperatures after gamma irradiation. Lipophilic and hydrophilic browning pigments increased with storage time particularly at ambient temperature, even though initial 5 kGy irradiation did not affect the formation of pigments significantly. This results were confirmed by the instrumental color determinations, Hunter color L, a, b and ΔE. With respect to changes in relative fatty acid compositions, storage period and temperature were more influential factors than gamma irradiation. Irradiation at 5 kGy induced insignificant changes in the total flavor profiles of stored anchovies, which were mainly composed of n-dodecanal(26.7%), n-pentadecane(22.2%), n-octanal(4.9%) and 2-pentylfuran(3.4%).

• Journal of Pharmaceutical Investigation
• /
• v.19 no.1
• /
• pp.21-27
• /
• 1989

Kinetic and thermodynamic aspects of the interface transfer of cefoperazone and its pivaloyloxymethyl ester were studied in a two-phase system composed of aqueous buffers and n-octanol by using the absolute reaction rate theory. In terms of the net thermodynamic parameters for the process, ${\Delta}S$ increased and ${\Delta}F$ decreased as the lipophilicity increased. With the increased ratio of forward $(k_f)$ to backward rate constants $(k_b)$, the ester was more lipophilic than cefoperazone, but the aqueous solubility was reduced.

• KSTLE International Journal
• /
• v.9 no.1_2
• /
• pp.26-30
• /
• 2008

This study examined the surface modification characteristics of NBR using sealing in automobile. Surfaces of NBR were modified by RF power Ar plasma treatment. In experiment, pressure, flux, temperature were fixed and RF bias voltage. Treatment time was changed. In friction test, we used PTFE grease. After modification, surfaces of NBR showed many grooves, hydrophilic functional groups, and lipophilic functional groups. As increasing treating voltage and time, the amount of them was increased. And wetting angle and friction coefficient was decreased with increasing treating voltage and time. However, the pattern of changing friction coefficient was not fixed.

• Journal of Food Hygiene and Safety
• /
• v.14 no.1
• /
• pp.84-89
• /
• 1999

Octenylscuccinated corn starches prepared by reaction of corn starch with 1-octenylsuccinic anhydride(OSAn) and their degree of substitution (DS), reaction efficiency(RE), residual octenylsuccinic acid (OSA), and physicochemical properties were compared with those of the native corn starch. DS increased with increase of OSAn and RE was much nearly the same regardless of increased of OSAn. The content of residual of residual OSA was significantly lower than that of regulation of food additives. And as washing frequency of dispersion of the reactant was increased, the content of residual OSA of octenylsuccinated starch was decreased. Raid Visco-Analyzer initial pasting temperature and setback of octenylsuccinated starches decreased whereas peak viscosity and breakdown increased. When DS of octenylsuccinated starches increased, temperature of initial gelatinization of octenylscuccinated starches drastically decreased. The octenylsuccinated starches also formed clearer pastes. The solubility was much nearly the same regardless of increase of DS at 7$0^{\circ}C$ but the swelling power increased 1.2~1.7 times higher than that of native corn starch at 7$0^{\circ}C$. The water binding capacity of octenylsuccinated starches also decreased.

• Mass Spectrometry Letters
• /
• v.5 no.1
• /
• pp.30-33
• /
• 2014

A solid phase extraction (SPE) method was optimized for the quantitative analysis of perfluorooctanoic acid (PFOA) in serum using hydrophilic-lipophilic balance SPE and LC-MS/MS. Fetal bovine serums spiked with $^{13}C_8$-PFOA before or after SPE were used as test samples for evaluation of the SPE efficiency. Simultaneous evaluation of matrix effects and absolute SPE recovery for $^{13}C_8$-PFOA in serum using different sample pre-treatments and SPE conditions allowed optimization of SPE process efficiency with minimal matrix effect and decent SPE recovery. Introduction of protein precipitation as a sample pre-treatment procedure for serum samples before SPE generally decreased matrix effect in LC-MS/MS analysis and provided more stable recovery of PFOA.

• Journal of Marine Bioscience and Biotechnology
• /
• v.1 no.4
• /
• pp.225-231
• /
• 2006

The secondary metabolites from Taiwanese marine soft corals and sponges have attracted much attention because they possess considerable potential biological activities. To explore the origin of bioactivity, many cytotoxic natural products were isolated and characterized in the past few years. For examples, The lipophilic extracts from marine sponges Petrosia elastica and Ircinia formosana were found active against several human tumor cells. The investigation of the gorgonian Junceela has also resulted in the discovery of a series of new juncenolides. Bioassay-directed fractionation of Clavularia viridis yielded seven new prostanoids. These compounds have been tested and evaluated as potential antitumor agents. The soft corals of the genus Cespitularia produced novel secondary metabolites with diverse chemical structures and interesting biological activities. Four new norditerpenoids, designated cespitulactones and cespihypotins were isolated from Cespitularia hypotentaculata. Cespitulactones are novel structures having a bond cleavage between C-10 and C-11. In addition, three novel diterpenes were isolated from C. taeniata and designated cespitulactams A, B and C having a phenylethyl amino side chain.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.3
• /
• pp.361-364
• /
• 2004

The potentiometric response of electrode no. 4 based on 1,3-bisbridged cofacial-calix[6]crown-5-ether (IV) gave a sub-Nernstian (45.0 mV/decade) response and the best detection limit (-log $a_{ep}$ = 4.73) towards epinephrine. The responses are decreasing in the order of epinephrine > $K^+$, dopamine > $NH_4^+$ > norepinephrine > $Na^+$. It is remarkable that the proposed electrode shows the reasonable selectivity to epinephrine against other catecholamine neurotransmitters (dopamine and norepinephrine) as well as alkali metal ions.

• Korean Journal of Clinical Pharmacy
• /
• v.3 no.1
• /
• pp.61-70
• /
• 1993

A new cephalosporin derivate, cefazolin phthalidyl ester(CFZ-PT) was synthesized to improve oral absorption and bioavailability of parent drug by esterification of sodium cefazolin(CFZ). Partition coefficient studies showed that CFZ-PR is more lipophilic than CFZ. The pharmacokinetic characteristics of CFZ-PT and CFZ preparations were compared following oral administrations of these compounds to rabbits. The analysis of CFZ in plasma was conducted by HPLC method. The ester compound was not detected in plasma following oral administration of CFZ-PT was increased by yielding 3.5-fold bioavailability rather than CFZ. From the results of this experiment, it was concluded that CFZ-PT could be a novel prodrug of CFZ which can improve the oral bioavailability of CFZ.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.6
• /
• pp.873-877
• /
• 2004

The relationship between the behaviors of c.c.lipase back-extraction and their percolation phenomena by using AOT reverse micellar systems (RVMS) has been studied by the addition of a small amount of additives to organic phase such as thiols and nonionic-surfactants focusing on micelle-micelle interactions. The values of ${\beta}_t$ defined by the variation of percolation processes and back-extraction behaviors of c.c.lipase have a good linear correlation. The hydrophobicity of additive molecules suppressing the cluster formation of reverse micelles (high values of ${\beta}_t$) improved the back-extraction behavior of c.c.lipase. The back-extraction fraction and its rate of c.c.clipase are increased with decreasing of the value of hydrophilic lipophilic balance (HLB) and increasing of the hydrophobicity per additive molecules added to reverse micellar systems (RVSM) in the same additives concentration.