Identification of ML106 Phase 1 Metabolites in Human Liver Microsomes Using High-Resolution Quadrupole-Orbitrap Mass Spectrometry

조준현,남웅식,김선주,이두현,민경훈,이태호,이상규 사단법인 한국질량분석학회 2016 Mass spectrometry letters Vol.7 No.3

High-resolution quadrupole-Orbitrap mass spectrometry (HRMS), with high-resolution (> 10,000 at full-width at half-maximum) and accurate mass (< 5 ppm deviation) capabilities, plays an important role in the structural elucidation of drug metabolites in the pharmaceutical industry. ML106, a derivative of imidazobenzimidazole, decreased melanin content and tyrosinase activity in a dose-dependent manner. Here, we investigated the phase 1 metabolic pathway of ML106 using HRMS in human liver microsomes (HLMs) and recombinant cDNA-expressed cytochrome P450 (CYP). After the incubation of ML106 with pooled HLMs and recombinant cDNA-expressed CYP in the presence of NADPH, five phase 1 metabolites, including three mono-hydroxylated metabolites (M1-3) and two di-hydroxylated metabolites (M4 and M5), were investigated. The metabolite structures were postulated by the elucidation of protonated mass spectra using HRMS. The CYP isoforms related to the hydroxylation of ML106 were studied after incubation with recombinant cDNA-expressed CYP. Here, we identified the phase 1 metabolic pathway of ML106 induced by CYP in HLMs.

Headspace GC-MS Analysis of Spring Blossom Fragrance at Chungnam National University Daedeok Campus

Yeonwoo Choi,Sanghyun Lee,Young-Mi Kim,Huu-Quang Nguyen,김정권,이재범 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

There are many types of spring blossoms on the Daedeok campus of Chungnam National University (CNU) at the area of 1,600,000 square meters. As an assignment for the class of Analytical Chemistry I for second-year undergraduate stu- dents, 2021, flower petals collected from various floral groups (Korean azalea, Korean forsythia, Dilatata lilac, Lilytree, Lily magnolia, and Prunus yedoensis) were analyzed using headspace extraction coupled to gas chromatography-mass spectrometry (HS-GC-MS) to study the aromatic profiles and fragrance compounds of each sample group. Various types of compounds asso- ciated with the aroma profiles were detected, including saturated alcohols and aldehydes (ethanol, 1-hexanol, and nonanal), ter- penes (limonene, pinene, and ocimene), and aromatic compounds (benzyl alcohol, benzaldehyde). The different contribution of these compounds for each floral type was visualized using statistical tools and classification models based on principal compo- nent analysis with high reliability (R 2 = 0.824, Q 2 = 0.616). These results showed that HS-GC-MS with statistical analysis is a powerful method to characterize the volatile aromatic profile of biological specimens.

The Advanced Analytical Method Through the Quantitative Comparative Study of Taurine in Feed Using LC-MS/MS

Yeong Jun Seon,Hyung Ju Seo,Jiye Yoon,Hyunjeong Cho,Sunghie Hong,Seung Hwa Le,Tae Woong Na 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

Taurine is a type of sulfur-containing amino acid having a sulfate functional group, that is biosynthesized from cyste- ine. It is mainly distributed in high concentrations in animal tissues and is known to have various effects such as osmotic pres- sure control, calcium control, anti-inflammatory, antioxidant, and hepatocellular protection. Also, taurine deficiency causes a variety of symptoms, including visual impairment. In particular, in the case of cats, taurine is not biosynthesized and must be supplied through food, so it is classified as an essential amino acid. In this study, an analysis method using mass spectrometry was developed instead of the commonly used derivatization method to quickly, environmentally, and precisely analyze taurine in various animal feeds. The developed analytical method showed good linearity (R 2 > 0.99), accuracy (81.97-105.78%), and pre- cision (0.07-12.37%). In addition, the developed method was further verified through quantitative comparison with the derivat- ization method. This developed method was used in the determination of taurine in 20 animal feed samples obtained from South Korea. The levels of taurine found ranged from 81.53 to 6,743.53 mg/kg. The developed analysis method will be used for the detection and quantification of taurine in domestic feed.

Relative Quantification of Glycans by Metabolic Isotope Labeling with Isotope Glucose in Aspergillus niger

최수현,Ye-Eun Cho,Do-Hyun Kim,Jin-il Kim,Jihee Yun,Jae-Yoon Jo,Jae-Min Lim 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

Protein glycosylation is a common post-translational modification by non-template-based biosynthesis. In fungal biotechnology, which has great applications in pharmaceuticals and industries, the importance of research on fungal glycopro- teins and glycans is accelerating. In particular, the importance of quantitative analysis of fungal glycans is emerging in research on the production of filamentous fungal proteins by genetic modification. Reliable mass spectrometry-based techniques for quantitative glycomics have evolved into chemical, enzymatic, and metabolic stable isotope labeling methods. In this study, we intend to expand quantitative glycomics by metabolic isotope labeling of glycans in Aspergillus niger, a filamentous fungus model, by the MILPIG method. We demonstrate that incubation of filamentous fungi in a culture medium with carbon-13 labeled glucose (1- 13 C 1 ) efficiently incorporates carbon-13 into N-linked glycans. In addition, for quantitative validation of this method, light and heavy glycans are mixed 1:1 to show the performance of quantitative analysis of various N-linked glycans simultaneously. We have successfully quantified fungal glycans by MILPIG and expect it to be widely applicable to glycan expression levels under various biological conditions in fungi.

A Sensitive, Efficient, and Cost-Effective Method to Determine Rotigotine in Rat Plasma Using Liquid-Liquid Extraction (LLE) and LC-MRM

Ji Seong Kim,Yong Jin Jang,Jin Hee Kim,Jin Hwan Kim,Jae Hee Seo,Il-Ho Park,강명주,최용석 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

Rotigotine (RTG) is a non-ergot dopamine agonist used to manage the early stage of Parkinson’s disease (PD) as transdermal patch. However, the poor medication compliance of PD patients and skin issues related with repeated applications of RTG patches lead to the search for alternative formulations and it also requires appropriate analytical methods for their in vivo evaluation. Thus, here, a sensitive, efficient, and cost-effective method to determine RTG in rat plasma using liquid-liquid extraction (LLE) and multiple reaction monitoring was developed. The use of 20 µL of rat plasma for sample treatment, 8-OH- DPAT as the internal standard, and methyl tert-butyl ether as the LLE solvent in the present method gives it advantages over pre- vious methods for the analysis of RTG in biological samples. The good analytical performance of the developed method was confirmed in specificity, linearity (the coefficient of determination ≥0.999 within 0.1-100 ng/mL), sensitivity (the lower limit of quantitation at 0.1 ng/mL), accuracy (81.00–115.05%), precision (≤10.75%), and recovery (81.00-104.48%) by following the FDA guidelines. Finally, the applicability test of the validated method to the in vivo evaluation of a RTG formulation showed that the present method is the only method which can be accurately applied to that longer than 24 hours, critical for the develop- ment of formulations with reduced dosing frequencies. Therefore, the present method could contribute to the development of new RTG formulations helpful to people suffering from PD.

Inhibitory Effects of Dietary Schisandra Supplements on CYP3A Activity in Human Liver Microsomes

Bae-Gon Kang,Eun-Ji Park,So-Young Park,Kwang-Hyeon Liu 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

Schisandra chinensis and its fruits have been used as a traditional herbal medicine to treat liver dysfunction, fatigue, and chronic coughs. Several in vitro and in vivo studies suggested that dibenzocyclooctadiene lignans present in Schisandra fruits strongly inhibit CYP3A4 activity. However, reports on the inhibitory potential of dietary Schisandra supplements against CYP3A activity are limited despite their increasing consumption as dietary supplements. In this study, we evaluated the CYP3A-inhibitory potential of four dietary Schisandra supplements in human liver microsomes. At a concentration of 0.05 mg/mL, Schisandra sup- plements from Nature’s Way, Swanson, Planetary Herbals, and Only Natural inhibited CYP3A activity by 93.9, 70.8, 33.6, and 24.8%, respectively. Nature’s Way, which exhibited the strongest inhibition against CYP3A, had the highest contents of gomisin B and gomisin C, which potently inhibit CYP3A activity. The in vivo pharmacokinetics of this product should be examined to determine whether the clinical relevance of inhibiting CYP3A activity by dietary Schisandra supplementation.

Simultaneous Liquid Chromatography Tandem Mass Spectrometric Determination of 35 Prohibited Substances in Equine Plasma for Doping Control

Young Beom Kwak,Jundong Yu,Hye Hyun Yoo 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

Many therapeutic class drugs such as beta-blocker, corticosteroids, NSAIDs, etc are prohibited substances in the horse racing industry. Liquid chromatography-tandem mass spectrometry (LC–MS/MS) technology makes it possible to isolate drugs from interference, enables various drug analyses in complex biological samples due to its sensitive sensitivity, and has been successfully applied to doping control. In this paper, we describe a rapid and sensitive method based on solid-phase extraction (SPE) using solid phase cartridge and LC–MS/MS to screen for different class’s 35 drug targets in equine plasma. Plasma samples were pretreated by SPE with the NEXUS cartridge consisted non-polar carbon resin and minimum buffer sol- vent. Chromatographic separation of the analytes was performed on ACQUITY HSS C18 column (2.1 × 150 mm, 1.8 µm). The elution gradient was conducted with 5 mM ammonium formate (pH 3.0) in distilled water and 0.1% formic acid in acetonitrile at a flow rate of 0.25 mL/min. The selected reaction monitoring (SRM) mode was used for drug screening with multiple transitions in the positive ionization mode. The specificity, limit of detection, recovery, and stability was evaluated for validation. The method was found to be sensitive and reproducible for drug screening. The method was applied to plasma sample analysis for the proficiency test from the Association of Racing Chemist.

Comparative Analysis of the Phyto-compounds Present in the Control and Experimental Peels of Musa paradisiaca used for the Remediation of Chromium Contaminated Water

Vidhya Kaniyappan,Regina Mary Rathinasamy,Job Gopinath Manivanan 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

Banana peels are also widely used as bio-adsorbent in the removal of chemicals contaminants and heavy metals from water and soil. GC-MS plays an essential role in the phytochemical analysis and chemo taxonomic studies of medicinal plants con- taining biologically active components. Intrinsically, with the use of the flame ionization detector and the electron capture detector which have very high sensitivities, Gas chromatography can quantitatively determine materials present at very low concentrations and most important application is in pollution studies. In the present study banana peels were used as bio-adsorbent to remediate the heavy metal contaminated water taken from three different stations located around the industrial belts of Ranipet, Tamilnadu, India. The AAS analysis of the samples shows a decrement of chromium concentration of 98.93%, 96.16% and 96.5% in Station 1, 2 and 3 respectively which proves the efficiency of the powdered peels of Musa paradisiaca. The GC-MS analysis of the control and treated peels of Musa paradisiaca reveals the presence of phytochemicals like Acetic Acid, 1-Methylethyl Ester, DL-Glyceraldehyde Dimer, N-Hexadecanoic Acid, 3-Decyn-2-Ol, 26-Hydroxy, Cholesterol, Ergost-25-Ene-3,5,6,12-Tetrol, (3.Beta.,5.Alpha.,6.Beta.,12.Beta.)-, 1-Methylene-2b- Hydroxymethyl-3, and 3-Dimethyl-4b-(3-Methylbut-2-Enyl)-Cyclohexane in the control banana peels. The banana peels which were used for the treatment reveals the changes and alteration of the phytochemicals. It is concluded that the alteration in phytochemicals of the experimental banana peels were due to adsorption of chromium heavy metal from the sample.

Analysis of Amyloid Beta 1-16 (Aβ16) Monomer and Dimer Using Electrospray Ionization Mass Spectrometry with Collision-Induced Dissociation

Kyoung Min Kim,Ho-Tae Kim 사단법인 한국질량분석학회 2022 Mass spectrometry letters Vol.13 No.4

The monomer and dimer structures of the amyloid fragment Aβ(1–16) sequence formed in H 2 O were investigated using electrospray ionization mass spectrometry (MS) and tandem MS (MS/MS). Aβ16 monomers and dimers were indicated by signals representing multiple proton adduct forms, [monomer+zH] n+ (=M z+ , z = charge state) and [dimer+zH] z+ (=D z+ ), in the MS spectrum. Fragment ions of monomers and dimers were observed using collision-induced dissociation MS/MS. Peptide bond dissociation was mostly observed in the D1–D7 and V11–K16 regions of the MS/MS spectra for the monomer (or dimer), regardless of the monomer (or dimer) charge state. Both covalent and non-covalent bond dissociation processes were indicated by the MS/MS results for the dimers. During the non-covalent bond dissociation process, the D 3+ dimer complex was separated into two components: the M 1+ and M 2+ subunits. During the covalent bond dissociation of the D 3+ dimer complex, the b and y fragment ions attached to the monomer, (M+b 10-15 ) z+ and (M+y 9-15 ) z+ , were thought to originate from the dissociation of the M 2+ monomer component of the (M 1+ +M 2+ ) complex. Two different D 3+ complex geometries exist; two distinguished interaction geometries resulting from interactions between the M 1+ monomer and two different regions of M 2+ (the N-terminus and C-termi- nus) are proposed. Intricate fragmentation patterns were observed in the MS/MS spectrum of the D 5+ complex. The complicated nature of the MS/MS spectrum is attributable to the coexistence of two D 5+ configurations, (M 1+ +M 4+ ) and (M 2+ +M 3+ ), in the Aβ16 solution.

Quantification of Three Prohibited Anabolic-Androgenic Steroids in Equine Urine using Gas Chromatography-Tandem Mass Spectrometry

Young Beom Kwak,Shaheed Ur Rehman,Hye Hyun Yoo 사단법인 한국질량분석학회 2023 Mass spectrometry letters Vol.14 No.3

Anabolic-androgenic steroids (AAS) are used illegally to enhance muscle development and increase strength and power. In this study, a reliable, and sensitive quantitative method was developed and validated using heptafluorobutyric acid anhydride (HFPA) derivatives for the simultaneous detection of prohibited AAS (testosterone [TS], boldenone [BD], 5α-estrane- 3β,17α-diol [EAD]) using gas chromatography-tandem mass spectrometry (GC-MS/MS). For processing the samples, solid phase extraction, methanolic hydrolysis, and liquid-liquid extraction were used. For detection using mass spectrometry, the mul- tiple reaction monitoring (MRM) mode was used with the electron ionization (EI) positive mode. The method was evaluated for selectivity, linearity, lower limit of quantification, intra- and inter-day precision, accuracy, and stability. The results showed that the method was accurate and reproducible for the quantitation of the three steroids. The developed method was finally applied to the analysis of a suspect gelding urine sample received from the Asian Quality Assurance Program (AQAP).