17 results on '"Shihoko Nakano"'
Search Results
2. Application of probe electrospray ionization mass spectrometry to the analysis of poisons and drugs in adulterated foods and beverages
- Author
-
Akihiro Miki, Ryutaro Asai, Hiroe Kamata, Munehiro Katagi, Atsushi Nitta, Misato Wada, Keiko Sasaki, Tasuku Murata, Shuntaro Matsuta, Koretsugu Ogata, Tooru Kamata, Shihoko Nakano-Fujii, Akari Ishikawa, Hidenao Kakehashi, Hiroshi Nishioka, Noriaki Shima, and Hitoshi Tsuchihashi
- Subjects
Chromatography ,Chemistry ,Electrospray ionization - Published
- 2021
3. Development of a new method for cyanide determination using dimethoxytriazinyl (DMT) derivatization
- Author
-
Tooru Kamata, Misato Wada, Noriaki Shima, Shihoko Nakano, Keiko Sasaki, Hiroe Kamata, Akari Ishikawa, Hiroshi Nishioka, Munehiro Katagi, Atsushi Nitta, Hidenao Kakehashi, Ryutaro Asai, Akihiro Miki, and Shuntaro Matsuta
- Subjects
chemistry.chemical_compound ,Chromatography ,chemistry ,Cyanide ,Gas chromatography–mass spectrometry ,Derivatization - Published
- 2020
4. Discrimination between internal and external uses by analysis of urine and blood from diphenhydramine users
- Author
-
Akari Ishikawa, Hiroshi Nishioka, Misato Wada, Atsushi Nitta, Shihoko Nakano, Hiroe Kamata, Shuntaro Matsuta, Ryutaro Asai, Tooru Kamata, Akihiro Miki, Noriaki Shima, Munehiro Katagi, Keiko Sasaki, and Hidenao Kakehashi
- Subjects
business.industry ,Anesthesia ,Diphenhydramine ,medicine ,Urine ,business ,medicine.drug - Published
- 2020
5. Development of the Exact Mass Database of Surfactants and Its Forensic Application
- Author
-
Shihoko Nakano, Noriaki Shima, Toru Kamata, Hitoshi Tsuchihashi, Akihiro Miki, Hiroshi Nishioka, Keiko Sasaki, Shuntaro Matsuta, Munehiro Katagi, Hidenao Kakehashi, and Hiroe Kamata
- Subjects
Mass ,Information retrieval ,Development (topology) ,Computer science - Published
- 2019
6. Intracellular accumulation-independent cytotoxicity of pentavalent organoantimony compounds in cultured vascular endothelial cells
- Author
-
Shuji Yasuike, Chika Yamamoto, Shihoko Nakano, Toshiyuki Kaji, Yuki Kitamura, and Takato Hara
- Subjects
Antimony ,Cell Survival ,Cell Culture Techniques ,Intracellular Space ,010501 environmental sciences ,Toxicology ,030226 pharmacology & pharmacy ,01 natural sciences ,Metal ,Structure-Activity Relationship ,03 medical and health sciences ,0302 clinical medicine ,Organometallic Compounds ,Animals ,Molecule ,Cytotoxicity ,Cells, Cultured ,0105 earth and related environmental sciences ,Molecular Structure ,Chemistry ,Endothelial Cells ,visual_art ,visual_art.visual_art_medium ,Biophysics ,Cattle ,Intracellular - Abstract
As the field of utilization of organic-inorganic hybrid molecules expands, the toxicology of these compounds is becoming more important. We have shown previously that there is a strong correlation between cytotoxicity and intracellular accumulation detected as metal content, which is modulated by the substituents, of organic-inorganic hybrid molecules. In this study, we investigated the cytotoxicity of pentavalent organoantimony compounds with three phenyl groups on cultured vascular endothelial cells. The results indicated that the cytotoxicity of pentavalent organoantimony compounds was not correlated with the hydrophobicity and intracellular accumulation of these compounds. Therefore, we suggest that hydrophobicity and intracellular accumulation are not necessarily predictive of cytotoxicity in organic-inorganic hybrid molecules.
- Published
- 2019
7. Dehydration-fragmentation mechanism of cathinones and their metabolites in ESI-CID
- Author
-
Atsushi Nitta, Yoshio Nishiyama, Ryutaro Asai, Hirohisa Nagatani, Hiroe Kamata, Akari Ishikawa, Shuntaro Matsuta, Misato Wada, Munehiro Katagi, Shihoko Nakano, Hidenao Kakehashi, Hisanori Imura, and Noriaki Shima
- Subjects
Reaction mechanism ,Cathinone ,Tertiary amine ,Electrospray ionization ,Metabolite ,medicine.disease ,Medicinal chemistry ,chemistry.chemical_compound ,chemistry ,medicine ,Amine gas treating ,Rearrangement reaction ,Dehydration ,Spectroscopy ,medicine.drug - Abstract
Various cathinone-derived designer drugs (CATs) have recently appeared on the drug market. This study examined the mechanism for the generation of dehydrated ions for CATs during electrospray ionization collision-induced dissociation (ESI-CID). The generation mechanism of dehydrated ions is dependent on the amine classification in the cathinone skeleton, which is used in the identification of CATs. The two hydrogen atoms eliminated during the dehydration of cathinone (primary amine) and methcathinone (secondary amine) were determined, and the reaction mechanism was elucidated through the deuterium labeling experiments. The hydrogen atom bonded to the amine nitrogen was eliminated with the proton added during ESI, in both of the tested compounds. This provided evidence that CATs with tertiary amine structures (such as dimethylcathinone and α-pyrrolidinophenones [α-PPs]) do not undergo dehydration. However, it was shown that the two major tertiary amine metabolites (1-OH and 2″-oxo) of CATs generate dehydrated ions in ESI-CID. The dehydration mechanisms of the metabolites of α-pyrrolidinobutiophenone (α-PBP) belongs to α-PPs were also investigated. Stable-isotope labeling showed the dehydration of the 1-OH metabolite following a simple mechanism where the hydroxy group was eliminated together with the proton added during ESI. In contrast, the dehydration mechanism of the 2″-oxo metabolite involved hydrogen atoms in three or more locations along with the carbonyl group oxygen, indicating that dehydration occurred via multiple mechanisms likely including the rearrangement reaction of hydrogen atoms. These findings presented herein indicate that the dehydrated ions in ESI-CID can be used for the structural identification of CATs.
- Published
- 2020
8. A new method for detection of nitrous oxide using azo coupling reaction
- Author
-
Hiroshi Nishioka, Ryutaro Asai, Shihoko Nakano, Hidenao Kakehashi, Tooru Kamata, Shuntaro Matsuta, Misato Wada, Akihiro Miki, Noriaki Shima, Munehiro Katagi, and Atsushi Nitta
- Subjects
chemistry.chemical_compound ,Chemistry ,010401 analytical chemistry ,Inorganic chemistry ,Nitrous oxide ,Azo coupling ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences - Published
- 2018
9. Effects of lipophilicity and functional groups of synthetic cannabinoids on their blood concentrations and urinary excretion
- Author
-
Keiko Sasaki, Misato Wada, Shuntaro Matsuta, Atsushi Nitta, Akihiro Miki, Ryutaro Asai, Hiroe Kamata, Hiroshi Nishioka, Munehiro Katagi, Noriaki Shima, Tooru Kamata, Shihoko Nakano, Hidenao Kakehashi, and Akari Ishikawa
- Subjects
Octanol ,Octanols ,Chromatography ,medicine.drug_class ,Cannabinoids ,Water ,Carboxamide ,Urine ,Pathology and Forensic Medicine ,Partition coefficient ,chemistry.chemical_compound ,Pharmacokinetics ,chemistry ,Valine ,Tandem Mass Spectrometry ,Lipophilicity ,Synthetic cannabinoids ,medicine ,Humans ,Law ,medicine.drug ,Chromatography, Liquid - Abstract
The influence of lipophilicity and functional groups of synthetic cannabinoids (SCs) on their blood concentrations and urinary excretion has been studied by analyzing blood and urine specimens sampled from drivers who were involved in a car crashes under the influence of SCs. A total of 58 specimens (26 urine and 31 blood specimens), sampled within 13h of the occurrence, were analyzed by liquid chromatography-tandem mass spectrometry. Fifteen SCs were detected in those specimens; the SCs detected were categorized as follows: Class 1, Naphthoyl/Benzoyl indole (EAM2201 and three other analogs); Class 2, Indole-3-carboxylate/carboxamide containing naphthol/quinol (5F-PB-22 and four other analogs); and Class 3, Indazole-3-carboxamide containing valine/tert-leucine derivative (5F-AMB and five other analogs). The calculated lipophilicity index log P, the octanol/water participation coefficient, of those SCs in Classes 1, 2, and 3 ranged between 5.01-8.14, 5.80-6.74 and 2.29-3.81, respectively. Class 3 SCs were detectable in 12 out of 13 urine specimens, but those in Classes 1 and 2 were not detected in urine. Our analytical results indicated that the boundary line for their detectability in urine lies between log P 4 and 5. The blood concentrations of Class 3 SCs varied widely (0.0036-31ng/ml) depending on their log P, while much smaller variation was observed among those in Class 2 (0.10-5.0ng/ml).
- Published
- 2019
10. Incorporation of zolpidem and methoxyphenamine into white hair strands after single administrations: Influence of hair pigmentation on drug incorporation
- Author
-
Shuntaro Matsuta, Ryutaro Asai, Shihoko Nakano, Noriaki Shima, Tooru Kamata, Hiroe Kamata, Akihiro Miki, Atsushi Nitta, Hitoshi Tsuchihashi, Akari Ishikawa, Hidenao Kakehashi, Misato Wada, Takako Sato, Munehiro Katagi, and Keiko Sasaki
- Subjects
Drug ,Male ,Narcotics ,medicine.medical_specialty ,Zolpidem ,Time Factors ,media_common.quotation_subject ,01 natural sciences ,Pathology and Forensic Medicine ,Methamphetamine ,03 medical and health sciences ,chemistry.chemical_compound ,Forensic Toxicology ,0302 clinical medicine ,Dermis ,Tandem Mass Spectrometry ,Internal medicine ,otorhinolaryngologic diseases ,medicine ,Humans ,Hypnotics and Sedatives ,030216 legal & forensic medicine ,Hair Color ,media_common ,integumentary system ,Methoxyphenamine ,Chemistry ,010401 analytical chemistry ,Hair analysis ,Middle Aged ,Mass spectrometric ,0104 chemical sciences ,White (mutation) ,Substance Abuse Detection ,Endocrinology ,medicine.anatomical_structure ,Hair root ,sense organs ,Law ,medicine.drug ,Chromatography, Liquid ,Hair - Abstract
In order to investigate the influence of pigmentation on the incorporation of drugs into hair, time-course changes in drug distribution along non-pigmented (white) hairs as well as pigmented (black) hairs plucked from the same subject was observed following single administrations of two basic drugs with different properties, zolpidem and methoxyphenamine. These drugs in 1-mm sections of single hair specimens were each determined by a liquid chromatography–tandem mass spectrometric procedure. During the early stage (12–36 h) after intake, for black hairs, both drugs were detected over the entire area of hair root (4–5 mm in length), in which notable concentration of these drugs in the hair bulb (0–1-mm segment from the bottom of hair root, Region 1) and lower concentrations in the upper dermis zone (1–2-mm to 3–4-mm or to 4–5-mm segments, Region 2) were commonly observed. Meanwhile, for white hairs, high drug concentrations in Region 1 as detected in black hairs were not observed although only small amounts of these drugs were detected over Region 2. Subsequent time-course changes in the concentration of drugs in hair demonstrated that the drugs once incorporated into white hair via Region 2 decreased gradually over the period from 24 h to 35 days after intake, but those of black hairs remained almost unchanged. These findings revealed here suggest that hair pigments have two important roles in the distribution of drugs: (1) incorporation of drugs into hair via Region 1, and (2) retention of already incorporated drugs in the hair tissue. These findings would be useful for discussing individual drug-use history based on hair analysis in the forensic fields.
- Published
- 2019
11. Surfactants in glyphosate products in Japan
- Author
-
Yoshito Kamijo, Tomoki Hanazawa, Noriaki Shima, Hiroe Kamata, Munehiro Katagi, Shihoko Nakano, Kiyotaka Usui, and Yuji Fujita
- Subjects
Toxicology ,Surface-Active Agents ,chemistry.chemical_compound ,chemistry ,Herbicides ,Glyphosate ,Glycine ,Humans ,Ingestion ,General Medicine ,Biology ,Polyethylene Glycols - Abstract
To the editorGlyphosate is used throughout the world as a non-selective herbicide. However, there are many reports of poisoning caused by glyphosate products, and ingestion of massive quantities of...
- Published
- 2019
12. Urinary excretion and metabolism of the α-pyrrolidinophenone designer drug 1-phenyl-2-(pyrrolidin-1-yl)octan-1-one (PV9) in humans
- Author
-
Keiko Sasaki, Shihoko Nakano, Kei Zaitsu, Hitoshi Tsuchihashi, Munehiro Katagi, Hiroshi Nishioka, Noriaki Shima, Akihiro Miki, Hidenao Kakehashi, Tooru Kamata, Hiroe Kamata, Takako Sato, and Shuntaro Matsuta
- Subjects
chemistry.chemical_classification ,Ketone ,Stereochemistry ,Biochemistry (medical) ,Diastereomer ,Alcohol ,Toxicology ,Tandem mass spectrometry ,Pyrrolidine ,Pathology and Forensic Medicine ,Hydroxylation ,Metabolic pathway ,chemistry.chemical_compound ,chemistry ,Carboxylate - Abstract
1-Phenyl-2-(pyrrolidin-1-yl)octan-1-one (PV9) and 16 metabolites, including diastereomers and conjugates, were identified or tentatively detected in human urine by gas chromatography–mass spectrometry and liquid chromatography–high-resolution tandem mass spectrometry. These urinary metabolites indicated that the metabolic pathways of PV9 include: (1) the reduction of ketone groups to their corresponding alcohols; (2) oxidation of the pyrrolidine ring to the corresponding pyrrolidone; (3) aliphatic oxidation of the terminal carbon atom to the corresponding carboxylate form, possibly through an alcohol intermediate (not detected); and (4) hydroxylation at the penultimate carbon atom to the corresponding alcohols followed by further oxidation to ketones, and combinations of these steps. In addition, results from the quantitative analyses of five phase-I metabolites using newly synthesized authentic standards suggested that the main metabolic pathway includes the aliphatic oxidation of terminal and/or penultimate carbons. Human metabolism of PV9 differed significantly from those of α-pyrrolidinovalerophenone and α-pyrrolidinobutiophenone, suggesting that the main metabolic pathways of α-pyrrolidinophenones significantly change depending on the alkyl chain length of the parent molecule.
- Published
- 2015
13. Dehydration-fragmentation mechanism of cathinones and their metabolites in ESI-CID.
- Author
-
Shuntaro Matsuta, Noriaki Shima, Hidenao Kakehashi, Akari Ishikawa, Ryutaro Asai, Atsushi Nitta, Misato Wada, Shihoko Nakano, Hiroe Kamata, Yoshio Nishiyama, Hirohisa Nagatani, Hisanori Imura, and Munehiro Katagi
- Subjects
DEHYDRATION reactions ,HYDROGEN atom ,DESIGNER drugs ,REARRANGEMENTS (Chemistry) ,SECONDARY amines ,CARBONYL group ,TERTIARY amines - Abstract
Various cathinone-derived designer drugs (CATs) have recently appeared on the drug market. This study examined the mechanism for the generation of dehydrated ions for CATs during electrospray ionization collision-induced dissociation (ESI-CID). The generation mechanism of dehydrated ions is dependent on the amine classification in the cathinone skeleton, which is used in the identification of CATs. The two hydrogen atoms eliminated during the dehydration of cathinone (primary amine) and methcathinone (secondary amine) were determined, and the reaction mechanism was elucidated through the deuterium labeling experiments. The hydrogen atom bonded to the amine nitrogen was eliminated with the proton added during ESI, in both of the tested compounds. This provided evidence that CATs with tertiary amine structures (such as dimethylcathinone and α-pyrrolidinophenones [α-PPs]) do not undergo dehydration. However, it was shown that the two major tertiary amine metabolites (1-OH and 2”-oxo) of CATs generate dehydrated ions in ESI-CID. The dehydration mechanisms of the metabolites of α-pyrrolidinobutiophenone (α-PBP) belongs to α-PPs were also investigated. Stable-isotope labeling showed the dehydration of the 1-OH metabolite following a simple mechanism where the hydroxy group was eliminated together with the proton added during ESI. In contrast, the dehydration mechanism of the 2”-oxo metabolite involved hydrogen atoms in three or more locations along with the carbonyl group oxygen, indicating that dehydration occurred via multiple mechanisms likely including the rearrangement reaction of hydrogen atoms. These findings presented herein indicate that the dehydrated ions in ESI-CID can be used for the structural identification of CATs. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
14. Intracellular accumulation-independent cytotoxicity of pentavalent organoantimony compounds in cultured vascular endothelial cells.
- Author
-
Takato Hara, Shihoko Nakano, Yuki Kitamura, Chika Yamamoto, Shuji Yasuike, and Toshiyuki Kaji
- Subjects
- *
VASCULAR endothelial cells , *ORGANOANTIMONY compounds , *PHENYL group , *PHENYL compounds , *METAL detectors - Abstract
As the field of utilization of organic-inorganic hybrid molecules expands, the toxicology of these compounds is becoming more important. We have shown previously that there is a strong correlation between cytotoxicity and intracellular accumulation detected as metal content, which is modulated by the substituents, of organic-inorganic hybrid molecules. In this study, we investigated the cytotoxicity of pentavalent organoantimony compounds with three phenyl groups on cultured vascular endothelial cells. The results indicated that the cytotoxicity of pentavalent organoantimony compounds was not correlated with the hydrophobicity and intracellular accumulation of these compounds. Therefore, we suggest that hydrophobicity and intracellular accumulation are not necessarily predictive of cytotoxicity in organic-inorganic hybrid molecules. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
15. Metabolism of the designer drug α-pyrrolidinobutiophenone (α-PBP) in humans: identification and quantification of the phase I metabolites in urine
- Author
-
Takako Sato, Shuntaro Matsuta, Munehiro Katagi, Kei Zaitsu, Hidenao Kakehashi, Akihiro Miki, Hitoshi Tsuchihashi, Hiroe Kamata, Noriaki Shima, Shihoko Nakano, Keiko Sasaki, Tooru Kamata, Koichi Suzuki, and Hiroshi Nishioka
- Subjects
chemistry.chemical_classification ,Propiophenones ,Chromatography ,Ketone ,Pyrrolidines ,medicine.drug_class ,Diastereomer ,Pyrrolidine ,Gas Chromatography-Mass Spectrometry ,Pathology and Forensic Medicine ,Designer Drugs ,Designer drug ,chemistry.chemical_compound ,Metabolic pathway ,chemistry ,Tandem Mass Spectrometry ,medicine ,Humans ,Gas chromatography–mass spectrometry ,Glucuronide ,Law ,Drug metabolism ,Chromatography, Liquid - Abstract
Urinary phase I metabolites of α-pyrrolidinobutiophenone (α-PBP) in humans were investigated by analyzing urine specimens obtained from drug abusers. Unequivocal identification and accurate quantification of major metabolites were realized using gas chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry with newly synthesized authentic standards. Two major phase I metabolic pathways were revealed: (1) reduction of the ketone group to 1-phenyl-2-(pyrrolidin-1-yl)butan-1-ol (OH-α-PBP, diastereomers) partly followed by conjugation to its glucuronide and (2) oxidation at the 2″-position of the pyrrolidine ring to α-(2″-oxo-pyrrolidino)butiophenone (2″-oxo-α-PBP) via the putative intermediate α-(2″-hydroxypyrrolidino)butiophenone (2″-OH-α-PBP). Of the phase I metabolites retaining the structural characteristics of the parent drug, OH-α-PBP was the most abundant in all specimens examined. Comparison of the phase I metabolism of α-PBP and α-pyrrolidinovalerophenone (α-PVP) suggested a relationship between the aliphatic side chain length and the metabolic pathways in α-pyrrolidinophenones: the shorter aliphatic side chain (1) led to more extensive metabolism via reduction of the ketone group than via the oxidation at the 2″-position of the pyrrolidine ring and (2) influenced the isomeric ratio of a pair of diastereomers.
- Published
- 2014
16. Characteristics of Bupleurum falcatum plants propagated through somatic embryogenesis of callus cultures
- Author
-
Shihoko Nakano, Noboru Hiraoka, Osamu Iida, Yutaka Tomita, Motoyoshi Satake, Miho Oyanagi, Tomoko Kodama, and Nobuyuki Yamada
- Subjects
chemistry.chemical_classification ,biology ,Somatic embryogenesis ,fungi ,Root weight ,Saponin ,food and beverages ,Plant Science ,General Medicine ,biology.organism_classification ,Tissue culture ,chemistry ,Dry weight ,Callus ,Botany ,Plant biochemistry ,Bupleurum falcatum ,Agronomy and Crop Science - Abstract
Various characteristics including the saponin content in the root of Bupleurum falcatum plants propagated in vitro through somatic embryogenesis of callus cultures were compared with those of the plants propagated by seeds. The asexually propagated plants had an aerial part of more uniform characteristics than those of sexually propagated ones. However, both the mean and variance of root weight of the former were significantly larger than those of the latter. As for the saponin content of the root on a dry weight basis, there was little difference between the two groups. The amounts of saikosaponins c and d in a root were significantly larger in the asexually propagated plants than in the sexually propagated ones.
- Published
- 1986
17. Metabolism of the designer drug α-pyrrolidinobutiophenone (α-PBP) in humans: Identification and quantification of the phase I metabolites in urine.
- Author
-
Shuntaro Matsuta, Noriaki Shima, Hiroe Kamata, Hidenao Kakehashi, Shihoko Nakano, Keiko Sasaki, Tooru Kamata, Hiroshi Nishioka, Akihiro Miki, Munehiro Katagi, Kei Zaitsu, Takako Sato, Hitoshi Tsuchihashi, and Koichi Suzuki
- Subjects
- *
DESIGNER drugs , *STIMULANTS , *DRUG metabolism , *URINALYSIS , *GAS chromatography/Mass spectrometry (GC-MS) , *KETONES - Abstract
Urinary phase I metabolites of α-pyrrolidinobutiophenone (α-PBP) in humans were investigated by analyzing urine specimens obtained from drug abusers. Unequivocal identification and accurate quantification of major metabolites were realized using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry with newly synthesized authentic standards. Two major phase I metabolic pathways were revealed: (1) reduction of the ketone group to 1-phenyl-2-(pyrrolidin-1-yl)butan-1-ol (OH-α-PBP, diastereomers) partly followed by conjugation to its glucuronide and (2) oxidation at the 200-position of the pyrrolidine ring to α-(200-oxo-pyrrolidino)butiophenone (200-oxo-α-PBP) via the putative intermediate α-(200-hydroxypyrrolidino)butiophenone (200-OH-α-PBP). Of the phase I metabolites retaining the structural characteristics of the parent drug, OH-α-PBP was the most abundant in all specimens examined. Comparison of the phase I metabolism of α-PBP and α-pyrrolidinovalerophenone (α-PVP) suggested a relationship between the aliphatic side chain length and the metabolic pathways in apyrrolidinophenones: the shorter aliphatic side chain (1) led to more extensive metabolism via reduction of the ketone group than via the oxidation at the 200-position of the pyrrolidine ring and (2) influenced the isomeric ratio of a pair of diastereomers. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.