• Proceedings of the PSK Conference
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• 2000.04a
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• pp.82-85
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• 2000

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.475-475
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• 2014

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.244.3-245
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• 2001

• Mass Spectrometry Letters
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• v.15 no.2
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• pp.79 -94
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• 2024

Over the past few decades, new psychoactive substances (NPS) have become prevailing. With the widespread emergence of NPS, phenethylamines (PEAs) have become one of the groups abused most which PEAs, along with other stimulants, make up the majority of stimulants. When determining the NPS, the methods for screening and confirmation are crucial which assesses the reliability of testimony. In this study, a set of GC/MS methods employing two derivatizing agents for determining 76 target PEAs in urine was established and further applied for authentic sample analysis. Five PEAs (N,N-DMA, PMMA, 4-CA, amphetamine, and methamphetamine) with contents over their LLOQs were detected in thirteen of the twenty tested samples. In order to compare the result from the GC/MS methods with the previously established LC-MS/MS method, Cohen's kappa coefficient and McNemar's test were applied for statistical analysis. Perfect agreement between GC/MS and LC-MS/MS techniques for determining target PEAs is demonstrated by the Kappa coefficient for each of the five detected targets.

• Natural Product Sciences
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• v.24 no.2
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• pp.93-98
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• 2018

Medicinal plants are potential sources of anticancer agents screening. A large number of phytochemicals, including triterpenoids, have been reported to have significant cytotoxic effects on cancer cells. From the fruits of Ligustrum japonicum Thunb., thirteen triterpenoids (1 - 13) were isolated and evaluated for their cytotoxic activity against Hela and HL-60 cells. As results, 8 (oleanolic acid) showed significant effects on Hela with $IC_{50}$ values of $5.5{\mu}M$, and moderate effects on HL-60 cells with $IC_{50}$ values of $55.9{\mu}M$. Meanwhile, 10 (oleanderic acid) and 11 ($3{\beta}$-acetoxy-urs-12-en-28-oic acid) exhibited moderate inhibitory effects on Hela with $IC_{50}$ value of 55.0 and $68.8{\mu}M$, respectively. Moreover, 10 showed cytotoxic effect on HL-60 cell line with $IC_{50}$ value of $63.9{\mu}M$. To our knowledge, this is the first report that oleanderic acid was isolated from L. japonicum and investigated in cytotoxic effects on Hela and HL-60 cells.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.345-351
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• 2012

In this study, 49 Korean herbal medicines have been investigated with an in vitro evaluation system using glycation end products (AGEs) formation inhibitory activity. Of these, 18 herbal medicines ($IC_{50}$ < $50{\mu}g/ml$) were found to have significant AGEs formation inhibitory activity. Of these, five herbal medicines ($IC_{50}$ < $50{\mu}g/ml$) were found to have significant AGEs formation inhibitory activity. Particularly, Mallotus japonicus (twigs and leaves), Rhus javanica (twigs and leaves), Boehmeria nivea (whole plants), Quercus acuta (stems), and Eurya japonica (stems) showed more potent inhibitory activity (approximately 9-37 fold) than the positive control aminoguanidine ($IC_{50}=76.47{\mu}g/ml$).

• Journal of Sensor Science and Technology
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• v.31 no.1
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• pp.6-11
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• 2022

To date, various techniques have been utilized to assess the contractility of cardiomyocytes and their response to drug-induced toxicity. However, these techniques are either invasive or involve complex fabrication methods and expertise. Here, we introduce the use of video-based analysis software to track the motion of cardiomyocytes and assess their contractility. The software, called "Tracker", is freely available and this is the first attempt at using it for cardiac contractility measurement. We used the software to measure the contractile properties of cells cultured on a rigid substrate and two flexible polydimethylsiloxane (PDMS) substrates having different elastic moduli day-wise up to eight days. Contractility was found to be highest in the most flexible substrate. Subsequently, the cardiotoxicity response of the cells on three different substrates was analyzed with verapamil. It was observed that the cells on rigid substrate were primarily affected by drug-induced toxicity, while the drug had a lesser impact on cells on the more flexible PDMS substrate. Evidently, the flexible substrate aided the maturation of cells and had lower drug toxicity, while the cells on PS could not fully mature. The assessment of cardiomyocytes using "Tracker" proved to be simple and reliable.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.168-175
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• 2013

Aldose reductase (AR) plays a central role in the development of the diabetic complications. Eighty one Korean herbal medicines have been investigated for inhibitory activities on AR. Among them, fourteen herbal medicines exhibited a significant inhibitory activity compared with 3,3-tetramethyleneglutaric acid (TMG) as positive control. Particularly, Xanthium strumarium (fruit, whole plant), Ilex cornuta (stem and leaf), Vitex rotundifolia(stem), Sophora flavescens (whole plant), Platycarya stobilacea (flower) showed two times more potent inhibitory activity than 3,3-tetramethyleneglutaric acid (TMG).

• BMB Reports
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• v.42 no.10
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• pp.623-630
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• 2009

Hsp90, an evolutionarily conserved molecular chaperone, is involved in the folding, stabilization, activation, and assembly of a wide range of 'client' proteins, thus playing a central role in many biological processes. Especially, several oncoproteins act as Hsp90 client proteins and tumor cells require higher Hsp90 activity than normal cells to maintain their malignancy. For this reason, Hsp90 has emerged as a promising target for anti-cancer drug development. It is still largely unknown how Hsp90 can recognize structurally unrelated client proteins. However, recent progress in structural studies on Hsp90 and its interaction with various co-chaperones has broadened our knowledge of how the Hsp90 ATPase activity, which is essential for its chaperone function, is regulated and coupled with the conformational changes of Hsp90 dimer. This review focuses on the roles of various Hsp90 co-chaperones in the regulation of the Hsp90 ATPase cycle, as well as in the selection of client proteins. In addition, the current development of Hsp90 inhibitors based on the structural information will be discussed.

• Korean Journal of Pharmacognosy
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• v.45 no.4
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• pp.354-358
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• 2014

Aldose reductase (AR) has been demonstrated to play important role in the development of the diabetic complications such as diabetic retinopathy, diabetic neuropathy and diabetic nephropathy. To discover novel treatments for diabetic complications from natural sources, 69 Korean herbal medicines have been investigated for inhibitory activities on AR. Among them, 7 herbal medicines, Eleutherococcus sessiliflorus (stems), Artemisia japonica (whole plants), Wisteria floribunda (leaves), Eurya japonica (stems, twigs and leaves, leaves), Ampelopsis brevipedunculata (stems) exhibited a significant inhibitory activity compared with 3,3-tetramethyleneglutaric acid as positive control.