• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.690-696
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• 2015

We micropropagated pear (Pyrus species) using shoot tips and nodal explants from three pear genotypes. The ability to establish shoot tip cultures, proliferate shoots, induce rooting, and acclimatize the resulting plantlets are all elements of in vitro micropropagation. Shoots were induced from shoot tips on Murashige and Skoog medium (MS) with five different plant growth regulator combinations. The highest shoot formation rates were achieved for the three genotypes using MS supplemented with 1.0 mg/L N⁶-benzyladenine (BA) and 0.1 mg/L gibberellic acid (GA₃). The maximum shoot number and shoot length for the three cultivars were recorded with 2.0 mg/L BA and 0.2 mg/L indole-3-butyric acid (IBA) in multiplication medium using nodal explants produced from microshoots. Nodal explants with one or two axillary buds cultured for three weeks initiated roots on medium supplemented with various concentrations of 1-naphthaleneacetic acid (NAA) or/and IBA in half-strength MS medium for adventitious rooting. The highest rooting response was with the combination of 0.2 mg/L NAA and 0.2 mg/L IBA. A combination of NAA and IBA resulted in a significant increase in the rooting ratio over NAA or IBA alone. In this medium, the root formation rate according to ranged from 68.9% for the BaeYun No. 3 genotype to 51.8% for the Hwanggeum genotype. We also investigated the influence of the concentration the polyamine phloroglucinol in rooting medium. For all three genotypes, the highest rooting ratio, longest root length, and greatest root number were observed in the treatments with 75-150 mg/L phloroglucinol. Most rooted plants were acclimatized successfully.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.1
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• pp.25-30
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• 2019

This study was aimed to examine the synergetic effects of photochemopreventive external agents composed of inorganic ZnO and esculetin. Zinc oxide (ZnO) is widely used in sunblocks because of its excellent biostability and little toxicity. Esculetin derived from Citrus Peel has an anti-oxidative effect. We made the hollow-shaped ZnO microsphere (MS), soaked it with esculetin (EZnO). We used SKH-1 mice to measure the photodamaging effects of UVB. The mice were divided into five groups as follows; UVB nontreated group (N), vehicle (C), esculetin (E), ZnO MS (ZnO), esculetin + ZnO MS(EZno) group. Each group of samples was topically applied to the dorsal skins before the UVB irradiation. The changes of collagen fibers in the skin tissues were observed by H & E staining and Van Gieson staining. The expression of mast cells in skin tissue was observed by immunohistochemical staining of tryptase present in the mast cell granules. Expression of inflammatory cytokines such as TNF-${\alpha}$, IL-$1{\beta}$, and MMP-9, which plays an essential role in wrinkle formation, was measured by RT-PCR. Interestingly, the composition of collagen fibers was better in the EZnO applied group than in the E or ZnO group. Moreover, mast cell expression and the expression of TNF-${\alpha}$, IL-$1{\beta}$, and MMP-9 mRNA were markedly suppressed in the EZnO group, indicating that the synergetic effects of esculetin and ZnO were excellent.

• Analytical Science and Technology
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• v.37 no.1
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• pp.25-38
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• 2024

The study aimed to investigate a novel approach by utilizing liquid chromatography (LC) and liquid chromatography-mass spectrometry (LC-MS) to separate, identify and characterize very nominal quantities of degradation products (DPs) of balsalazide along with its process related impurities without isolation from their reaction mixtures. The impurities along with balsalazide were resolved on spherisorb ODS2 (250×4.6 mm, 5.0 ㎛) column at room temperature using 0.2 M sodium acetate solution at pH 4.5 and methanol in the ratio of 55:45 (v/v) as mobile phase pumped isocratically at 1.0 mL/min as mobile phase and UV detection at 255 nm. The method shows sensitive detection limit of 0.003 ㎍/mL, 0.015 ㎍/mL and 0.009 ㎍/mL respectively for impurity 1, 2 and 3 with calibration curve liner in the range of 50-300 ㎍/mL for balsalazide and 0.05-0.30 for its impurities. The balsalazide pure compound was subjected to stress studies and a total of four degradation products (DPs) were formed during the stress study and all the DPs were characterized with the help of their fragmentation pattern and the masses obtained upon LC-MS/MS. The DPs were identified as 3-({4-[(E)-(4-hydroxyphenyl) diazenyl]benzoyl}amino)propanoic acid (DP 1), 4-[(E)-(4-hydroxyphenyl)diazenyl] benzamide (DP 2), 5-[(E)-(4-carbamoylphenyl)diazenyl]-2-hydroxybenzoic acid (DP 3) and 3-({4-[(E)-phenyldiazenyl]benzoyl}amino)propanoic acid (DP 4). Based on findings, it was concluded that, the proposed method was successfully applicable for routine analysis of balsalazide and its process related impurities in pure drug and formulations and also applicable for identification of known and unknown impurities of balsalazide.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.725-734
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• 2024

CYP102A1 from Bacillus megaterium is an important enzyme in biotechnology, because engineered CYP102A1 enzymes can react with diverse substrates and produce human cytochrome P450-like metabolites. Therefore, CYP102A1 can be applied to drug metabolite production. Terpinen-4-ol is a cyclic monoterpene and the primary component of essential tea tree oil. Terpinen-4-ol was known for therapeutic effects, including antibacterial, antifungal, antiviral, and anti-inflammatory. Because terpenes are natural compounds, examining novel terpenes and investigating the therapeutic effects of terpenes represent responses to social demands for eco-friendly compounds. In this study, we investigated the catalytic activity of engineered CYP102A1 on terpinen-4-ol. Among CYP102A1 mutants tested here, the R47L/F81I/F87V/E143G/L188Q/N213S/E267V mutant showed the highest activity to terpinen-4-ol. Two major metabolites of terpinen-4-ol were generated by engineered CYP102A1. Characterization of major metabolites was confirmed by liquid chromatography-mass spectrometry (LC-MS), gas chromatography-MS, and nuclear magnetic resonance spectroscopy (NMR). Based on the LC-MS results, the difference in mass-to-charge ratio of an ion (m/z) between terpinen-4-ol and its major metabolites was 16. One major metabolite was defined as 1,4-dihydroxyp-menth-2-ene by NMR. Given these results, we speculate that another major metabolite is also a mono-hydroxylated product. Taken together, we suggest that CYP102A1 can be applied to make novel terpene derivatives.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.35 no.1
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• pp.90-97
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• 2024

Objectives: This study aimed to explore the influence of depression severity, disease course, treatment status, and other factors on cognitive function in adolescents with depressive disorders. Methods: Participants who met the inclusion criteria were enrolled in the study. Sociodemographic data of each participant were recorded, including age, sex, and family history of mental disorders. Zung's Self-Rating Depression Scale was used to assess depression status in adolescents. Moreover, P300 and mismatch negativity (MMN) were used to objectively evaluate the participants' cognitive function. Results: Only 26.8% of the adolescents with depression received standard antidepressant treatment. The latencies of N2 (267.80±23.34 ms), P3 (357.71±32.09 ms), and MMN (212.10±15.61 ms) in the adolescent depression group were longer than those in the healthy control group (p<0.01). Further analysis revealed that the latency of MMN was extended with increased levels of depression in adolescents. The MMN latency was short in participants with depression receiving standardized treatment. Furthermore, the latency of MMN was positively correlated with the severity and duration of depression (correlation coefficients were 0.465 and 0.479, respectively) (p<0.01). Conclusion: Receiving standardized treatment and shortening the course of depression can reduce cognitive impairment in adolescents with depression.

• Natural Product Sciences
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• v.6 no.4
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• pp.189-192
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• 2000

A new isoflavone, $(+)-4'-O-methyl-8-C-{\beta}-D-glucopyranosylgenistein$, was isolated from the aerial parts of Spartidium saharae together with the known isoflavone, $(+)-8-C-{\beta}-D-glucopyranosylgenistein$ as well as dipiperidine alkaloids, (+)-ammodendrine and (+)-N-acetyl hystrine. Details of their structure elucidation are based on chemical and spectroscopic methods. N-formyl ammodendrine was detected by GC-MS. The potential chemotaxonomic value of the alkaloid content is explored. Cytotoxic activity has been determined for both alcoholic extract and isolated compounds.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1527-1535
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• 2012

Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms.

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.143-150
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• 1993

The metabolic profile of triprolidine, 2-[(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined. Urinary extracts obtained with enzyme hydrolysis were derivatized with MSTFA/TMSCl (N-methyl-N-trimethylsilyl trifluoroacetamide/trimethylchlorosilane) and analyzed by GC/MSD. In human urine, which were obtained after the oral administration with triprolidine, hydroxymethyltriprolidine, triprolidine carboxylic acid, oxotriprolidine carboxylic acid and unchanged triprolidine were detected. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from human urine was at 2 to 4 hours after the drug administration. Triprolidine and hydroxymethyl triprolidine were identified by comparison with authentic standards In chromatographic and mass spectral properties. Triprolidine carboxylic acid was detected as a major metabolite of its metabolites in the urine. Oxotriprolidine carboxylic acid and triprolidine carboxylic acid were tentatively identified by the interpretation of its mass spectral patterns. These data suggest that in human, hydroxylation of either the benzyl or pyrrolidine ring can occur during triprolidine elimination.

• Natural Product Sciences
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• v.10 no.3
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• pp.104-108
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• 2004

Five lignans including gomisin N (1), wuweizisu C (2), gomisin L1 (3), (+)-deoxyschizandrin (4), and gomisin J (5) have been isolated from the fruits of Schizandra chinensis. The structures of the isolated compounds were elucidated by analyzing MS and NMR spectra. Effects of the compounds isolated in this study on the dopamine content in PC12 cells were investigated to evaluate their inhibitory effectiveness. The gomisin N, wuweizisu C, and gomisin J showed 25.4%, 39.8%, and 35.1 %, respectively, inhibition effect on dopamine content in PC12 cells at the concentration of $50\;{\mu}g/ml$.

• Korean Journal of Materials Research
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• v.6 no.10
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• pp.1043.2-1048
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• 1996

자기기록의 고밀도화로 인해 보자력(Hc)이 큰 자기기록매체가 필요하게 되었다. 고보자력매체에 신호를 충분히 기록하기 위해서는 보다 강한 자장이 필요하다. 이 때문에 포화자화(Ms)가 큰 재료가 필요하며 고주파 영역에서 실효투자율($\mu$eff)이 높아야 한다. Fe계 합금박막은 이에 적합한 재료이다. 본 연구에서는 Fe의 결정자기이방성에 영향을 미치는 Si과 Fe의 격자 변형을 유도할 수 있는 B를 첨가하였다. Fe-B-Si 계 박막을 질소분위기 중에서 RF Matnetron Sputter로 제작하여 연자기적 특성에 관하여 고찰하였다. Fe91.49B4.01Si4.50at% 박막은 35$0^{\circ}C$에서 1시간 열처리를 행함으로써 약 900(10MHz) 정도의 투자율과 7.6Oe의 보자력을 나타냈으며 포화자화는 1300emu/㎤를 얻었다.