• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.219-227
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• 2015

This study was conducted to determine 10 preservatives (benzyl alcohol (BAl), phenoxyethanol (PE), benzoic acid (BA), sorbic acid (SA), methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP), isopropyl paraben (IPP), butyl paraben (BP), isobutyl paraben (IBP)) levels in 125 cosmetics (n = 125) for children by the simultaneous analysis of HPLC. The detection ranges were as follows; 0.01 ~ 0.91% (n = 35) for PE, 0.01 ~ 0.48% (n = 28) for BA, 0.01 ~ 0.78% (n = 9) for BAl, 0.01 ~ 0.11% (n = 3) for SA, 0.04 ~ 0.21% (n = 8) for MP, 0.02 ~ 0.09% (n = 8) for PP, and 0.04% (n = 1) for EP. The order of detection rates was cleanser (63%) > cream (48%) > sunscreen (46%) > lotion (38%) > oil (13%). At least one of target preservatives was contained in 50% (63/125) of samples and the content of the detected preservatives was within maximum allowed amount established by KFDA. Phenoxyethanol and benzoic acid were used more frequently than paraoxybenzoate esters (parabens) in cosmetics for children and the detected parabens was mainly the mixture of methyl paraben and propyl paraben.

• Food Science and Preservation
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• v.21 no.4
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• pp.529-535
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• 2014

To examine the levels of preservatives that occur naturally in food, wild plants used as commercial teas, rice cakes, or spices were studied according to the method of the Korean Food Code and analyzed with a gas chromatograph and HPLC. The levels of the natural preservatives (sodium dehydroacetate, sorbic acid, benzoic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, isopropyl p-hydroxybenzoate, propyl p-hydroxybenzoate, isobutyl p-hydroxybenzoate, butyl p-hydroxybenzoate, and propionic acid) in 21 cases were investigated against 15 kinds of wild plants. Six of 15 kinds of wild plants, such as pine needles, bamboo leaf, kudzu leaf, ramie leaf, mugwort, and nut pine leaf, were confirmed to have had sorbic acid, benzoic acid, and propionic acid. 8.201-21.839 mg/kg of benzoic acid was detected in the bamboo leaf, ramie leaf, pine needles, mugwort, kudzu leaf, and nut pine leaf. The sorbic acid contents of the bamboo leaf and the kudzu leaf were 5.630-24.995 mg/kg, respectively. The propionic acid content of the ramie leaf was 61.324-62.726 mg/kg. Nine kinds of wild plants, such as the Korean berchimia leaf, taro leaf, sasa borealis, lotus leaf, kuansh, chrysanthemum zawadskii, oak tree leaf, Chinese pepper leaf, and persimmon leaf, were not detected at the levels of the natural preservatives.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.297-305
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• 2022

Antioxidants are food additives that extend the shelf life of food products by preventing lipid rancidity caused by active oxygen. They can either be naturally-derived or manufactured synthetically via chemical synthesis. In this study, method validation of five synthetic antioxidants, namely butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhydroquinone, propyl gallate, and disodium ethylenediaminetetraacetic acid, was performed using a high performance liquid chromatography-ultraviolet visible detector, and the method applicability was evaluated by analyzing foods containing antioxidants. The coefficient of determination (R²) average was 0.9997, while the limit of detection and limit of quantification were 0.02-0.53 and 0.07-1.61 mg/kg, respectively. The intra and inter-day accuracies and precisions were 83.2±0.7%-98.7±2.1% and 0.1%-5.7% RSD, respectively. Inter-laboratory validation for accuracy and precision was conducted using the Food Analysis Performance Assessment Scheme quality control material. The results satisfied the guidelines presented by the AOAC International. In addition, the expanded uncertainty was less than 16%, as recommended by CODEX. Consequently, to enhance public health safety, the results of this study can be used as basis data for evaluating the intake of synthetic antioxidants and assessing their risks in Korea.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.928-941
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• 2022

This study aimed to analyze the microbiological composition and sensory characterization of fermented sausage using strains isolated from Kimchi (GK1, Pediococcus pentosaceus SMFM2016-GK1; NK3, P. pentosaceus SMFM2016-NK3), Doenjang (D1, Debaryomyces hansenii SMFM2021-D1), and spontaneously fermented sausage (S8, D. hansenii SMFM2021-S8; S6, Penicillium nalgiovense SMFM2021-S6). The control was commercial starter culture. Nine treatments were applied [GD (GK1+D1), GS (GK1+S8), GDS (GK1+D1+S8), ND (NK3+D1), NS (NK3+S8), NDS (NK3+D1+S8), GND (GK1+NK3+D1), GNS (GK1+NK3+S8), and GNDS (GK1+NK3+D1+S8)] by mixing lactic acid bacteria and yeast, and S6 was sprayed. The microbial composition of fermented sausage was analyzed [aerobic bacteria (AC), Lactobacillus spp. (LABC), Staphylococcus spp. (STPC), and yeast and mold (YMC)], and pH and electronic nose and tongue measurements were taken. The AC, LABC, STPC, and YMC values of the control and treatment groups tended to increase during fermentation (p>0.05). The STPC values of the GD, GS, ND, and GDS groups were similar to that of the control on day 3. The pH of the control on day 3 was significantly lower than that of the GD, ND, and GND groups (p<0.05). Higher levels of 4-methylpentanol, 2-furanmethanol, and propyl nonanoate, which provide a "fermented" flavor, were detected in the GD group compared to in the control and other treatment groups. GD and ND groups showed higher umami values than the control and other treatment groups. Therefore, it is expected that GD can be valuable as a starter culture unique to Korea when manufacturing fermented sausage.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1315-1322
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• 2006

The following study describes the gas chromatography-mass spectrometry (GC-MS) based screening and confirmation analysis of urinary androgenic steroids. Four commercially available solid-phase extraction (SPE) cartridges, Serdolit PAD-1, Sep-pak $C_{18}$, amino-propyl, and Oasis HLB, and three different extractive organic solvents, diethyl ether, methyl tert-butyl ether (MTBE), and n-pentane, were tested for sample preparation. Overall, Oasis HLB combined with MTBE extraction provided the highest recoveries in 39 of 46 total androgenic steroids examined and it showed a good extraction yield (>82.1%) for polar steroids, such as metabolites of fluoxymesterone, oxandrolone, and stanozolol, which gave a poor recovery in both n-pentane (9.2-64.3%) and diethyl ether (22.2-73.6%) extractions. All SPE sorbents tested showed potential, because they were efficient in extraction for most or selective steroids. When applied to positive urine samples based on the results obtained, the present method allowed selective and sensitive analysis for detection of urinary androgenic steroids. The experiments showed that the high-resolution MS method is clearly more efficient than the low-resolution MS technique for the detection of many urinary steroids. However, comprehensive sample clean-up procedures also might be needed especially in confirmation analysis to increase detectability.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.636-642
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• 1994

Essential amino acids involving in the catalytic mechanism of the $\beta$-D-xylosidase of Bacillus stearothermophilus were determined by chemical modification studies. Among various che- mical modifiers tested N-bromosuccinimide (NBS), $\rho$-hydroxymercurybenzoate (PHMB), N-ethylma- leimide, 1-[3-(di-ethylamino)-propyl]$-3-ethylcarbodi-imide (EDC), and Woodward's Reagent K(WRK)inactivated the enzyme, resulting in the residual activity of less than 20%. WRK reduced the enzyme activity by modifying carboxylic amino acids, and the inactivation reacion proceeded in the form of pseudo-first-order kinetics. The double-lagarithmic plot of the observed pseudo-first- order rate constant against the modifier concentration yielded a reaction order of 2, indicating that two carboxylic amino acids were essential for the enzyme activity. The $\beta$-D-xylosidase was also inactivated by N-ethylmaleimide which specifically modified a cysteine residue with a reaction order of 1, implying that one cysteine residue was important for the enzyme activity. Xylobiose protected the enzyme against inactivation by WRK and N-ethylmaleimide, revealing that carboxylic amino acids and a cysteine residue were present at the substrate-binding site of the enzyme molecule.

• Membrane Journal
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• v.6 no.4
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• pp.284-288
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• 1996

The crosslinked PVA/PAA membranes developed in our laboratory have been characterized for water-isopropyl alcohol mixture in terms of permeabilities and separation factor. When the feed mixture was 12wt% water, the permeability and the separation factor for PVA/PAA=75/25 membrane show $63g/m^{2}h$ and 1520 at $80^{\circ}C$, respectively. In case of 5wt% water in feed mixture, the permeability for PVA/PAA=75/25 membrane is $56g/m^{2}h$ at 8$0^{\circ}C$ while the separation factor is 1563.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.391-395
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• 1995

Several lines of evidence indicate that physiological activity of N-methyl-D-aspartate (NMDA) receptor was blocked by physiological concentration of $Mg^{2+}$ (1.2 mM). However, the activity of NMDA receptor may not be blocked totally with this concentration of $Mg^{2+}$ under elevated membrane potential by kainate. Here, we described the effect of $Mg^{2+}$ on NMDA receptor and how much of NMDA receptor functions could be activated by kainate. Effects of NMDA receptor antagonist on kainate-induced elevation of intracellualr $Ca^{2+}$ levels $([Ca^{2+}]_i)$ and extracellular glutamate level were examined in cultured rat cerebellar granule neurons. kainate-induced elevation of $([Ca^{2+}]_i)$ was not affected by physiological concentration of $Mg^{2+}$. Kainate-induced NMDA-induced elevation was blocked by the same concentration of $MG^{2+}$Kainate-induced elevation of [$([Ca^{2+}]_i)$ was decreased by 32% in the presence of NMDA antagonists, MK-801 and CPP (3-[2-carboxypiperazine-4-yl]propyl-1-phosphonic acid), in $Mg^{2+}$ free buffer. Kainate receptor-activated gluamate release was also decreased (30%) by MK-801 or CPP. These resuts show that certain extent of elevations of intracellular $Ca^{2+}$ and extracellular glutamate by kainate is due to coativation of NMDA receptors.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.232-237
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• 2003

The present study examined functional effects of a new selective phosphodiesterase type 5 inhibitor, 1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-thioxo-3-propyl-1H-pyrazolo[ 4,3]pyrimidin-5-yl)phenylsulphonyl]-4-methyl piperazine (KJH-1002), in the isolated rabbit corpus cavernosum (RCC). Relaxing effects of KJH-1002 were also compared with those of sildenafil, which is currently used as an oral therapy for penile erectile dysfunction. In the isolated RCC precontracted with phenylephrine, both KJH-1002 and sildenafil in the concentration range of 1 to 1000 nM, produced a comparable potentiation of the electical field stimulation-induced relaxation in a concentration-dependent manner. In the sodium nitroprusside (SNP)-induced relaxation, the $IC_{50}$/ values, concentrations of SNP required to produce a 50％ relaxation of the phenylephrine-induced contraction, were significantly decreased to the similar extent by treatments with KJH-1002 and sildenafil. The results suggest that a new selective phosphodiesterase type 5 inhibitor, KJH-1002, has an augmentative effect on penile erection comparable to that of sildenafil and can be useful for the treatment of erectile dysfunction.

• Journal of Medicine and Life Science
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• v.16 no.1
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• pp.34-38
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• 2019

Hypogonadism is a clinical syndrome that results in hormone deficiency and can be classified as 1) primary caused by the gonadal failure and 2) secondary by the hypothalamus-pituitary gland dysfunction and/or cardiometabolic complications. Recently the presence of thyroid hormone receptors in different testicular cell types was demonstrated, and thus thyroid dysfunctions would be another cause of secondary hypogonadism. Thus, we investigated the effects of perinatal hypothyroidism on hypogonadism in male Sprague-Dawley rats. Perinatal hypothyroidism was induced by daily administration of 0.05% 6-propyl-2-thiouracil (PTU) by tap water from gestation day 15, which were compared with negative control (PTU (-)) group. At postnatal day 28, hypothyroid pups were divided into 2 groups: PTU (+) group - continued PTU treatment and PTU (+/-) group - stopped PTU until postnatal day 49. Body weights, dehydrotesosterone (DHT), and testosterone levels were checked 2 and 3 weeks after grouping. Body weights were significantly decreased in PTU(+) and PTU(+/-) groups compared with PTU (-) group at postnatal day 28. 3 weeks later, PTU (+/-) group significantly gained weight compared with PTU (+) group. DHT and testosterone levels significantly decreased with PTU treatment, but increased 3 weeks after stopping PTU administration. Perinatal PTU-induced hypothyroid hypogonadism was sustained for 2 weeks after stopping PTU administration, but restored gonadal hormone levels 3 weeks after stopping PTU. These results suggest that researchers should design an experiment on hypothyroid hypogonadism based on the estimated period.