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Heesun Chung

Department of Forensic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.

3 papers in the library · 75 citations · publishing 2006-2024

Papers

Comparison of illegal drug use pattern in Taiwan and Korea from 2006 to 2014

Substance Abuse Treatment Prevention and Policy September 23, 2016 Ling‐yi Feng, Wenjing Yu, Wei-Ting Chang et al. 49 citations

Although methamphetamine remains a problem, new psychoactive substances (NPS) have become an emerging issue in both Taiwan and South Korea, though their patterns differ. Taiwan seizes much larger quantities of NPS, particularly ketamine, despite having far fewer controlled NPS items than Korea. These differences suggest the NPS come from different sources. Factors beyond geographical proximity, including drug policy and drug availability and accessibility, help explain the current status of illegal drug use in the two countries.

Quantification of MDMA and MDA in abusers' hair samples by semi‐micro column HPLC with fluorescence detection

Biomedical Chromatography June 1, 2006 Shinichi Nakamura, Mamoru Tomita, Mitsuhiro Wada et al. 24 citations

A sensitive method using high-performance liquid chromatography with fluorescence detection was developed to measure MDMA, MDA, methamphetamine, and amphetamine in human hair. Drugs were extracted from hair using trifluoroacetic acid in methanol and labeled with a fluorescent reagent. Separation was achieved on a reversed-phase column. Detection limits for MDMA, MDA, methamphetamine, and amphetamine were 0.25, 0.15, 0.25, and 0.19 ng/mg, respectively. Assay precision ranged from 1.5% to 6.8% for intra-day and 2.7% to 4.7% for inter-day measurements. The method was sensitive enough to detect these compounds in small hair samples and was applied to quantify drugs in six abusers' hair.

Crystal structure of an antibody specifically recognizing 3,4-methyl enedioxy methamphetamine through the epoxide moiety.

Biochemical and biophysical research communications November 12, 2024 Geonho Cheon, Dahyun Hwang, Truc Chi Le et al. 2 citations

Antibodies that detect MDMA (ecstasy) often also recognize its chemical analogue methamphetamine (METH), but two antibodies, 1bB11 and 1bF12, were identified that bind MDMA specifically without binding METH. The crystal structure of 1bB11 bound to MDMA, solved at 3.2 Å resolution, shows that key interactions involve the epoxide moiety of MDMA with residues S34 and Y36 of the antibody's light chain, and an additional interaction with E33 of the heavy chain. Mutagenesis confirmed these residues are important for binding. Comparing this structure to another antibody that binds both drugs revealed opposite binding orientations, providing a structural basis for developing a highly specific antibody for MDMA diagnosis.