The Experts below are selected from a list of 2313 Experts worldwide ranked by ideXlab platform
Hans-ulrich Humpf - One of the best experts on this subject based on the ideXlab platform.
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HT-2 Toxin 4-Glucuronide as New T-2 Toxin Metabolite: Enzymatic Synthesis, Analysis, and Species Specific Formation of T-2 and HT-2 Toxin Glucuronides by Rat, Mouse, Pig, and Human Liver Microsomes
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Tanja Welsch, Hans-ulrich HumpfAbstract:Glucuronides of the mycoToxin T-2 Toxin and its phase I Metabolite HT-2 Toxin are important phase II Metabolites under in vivo and in vitro conditions. Since standard substances are essential for the direct quantitation of these glucuronides, a method for the enzymatic synthesis of T-2 and HT-2 Toxin glucuronides employing liver microsomes was optimized. Structure elucidation by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry revealed that besides T-2 Toxin glucuronide and HT-2 Toxin 3-glucuronide also the newly identified isomer HT-2 Toxin 4-glucuronide was formed. Glucuronidation of T-2 and HT-2 Toxin in liver microsomes of rat, mouse, pig, and human was compared and Metabolites were analyzed directly by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). A distinct, species specific pattern of glucuronidation of T-2 and HT-2 Toxin was observed with interesting interindividual differences. Until recently, glucuronides have frequently been analyzed indirectly by qu...
Geum-sook Hwang - One of the best experts on this subject based on the ideXlab platform.
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Metabolic alterations in the bone tissues of aged osteoporotic mice
Scientific Reports, 2018Co-Authors: Miso Nam, Jeong-eun Huh, Min-sun Kim, Do Hyun Ryu, Jihyeong Park, Han-sung Kim, Soo Young Lee, Geum-sook HwangAbstract:Age-related osteoporosis is characterized by reduced bone mineralization and reduced bone strength, which increases the risk of fractures. We examined metabolic changes associated with age-related bone loss by profiling lipids and polar Metabolites in tibia and femur bone tissues from young (5 months old) and old (28 months old) male C57BL/6J mice using ultra-performance liquid chromatography quadrupole-time-of-flight mass spectrometry. Partial least-squares discriminant analysis showed clear differences in Metabolite levels in bone tissues of young and old mice. We identified 93 lipid species, including free fatty acids, sphingolipids, phospholipids, and glycerolipids, that were significantly altered in bone tissues of old mice. In addition, the expression of 26 polar Metabolites differed significantly in bone tissues of old mice and young mice. Specifically, uremic Toxin Metabolite levels (p-cresyl sulfate, hippuric acid, and indoxylsulfate) were higher in bone tissues of old mice than in young mice. The increase in p-cresyl sulfate, hippuric acid, and indoxylsulfate levels were determined using targeted analysis of plasma polar extracts to determine whether these Metabolites could serve as potential osteoporosis biomarkers. This study demonstrates that LC-MS-based global profiling of lipid and polar Metabolites can elucidate metabolic changes that occur during age-related bone loss and identify potential biomarkers of osteoporosis.
Tanja Welsch - One of the best experts on this subject based on the ideXlab platform.
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HT-2 Toxin 4-Glucuronide as New T-2 Toxin Metabolite: Enzymatic Synthesis, Analysis, and Species Specific Formation of T-2 and HT-2 Toxin Glucuronides by Rat, Mouse, Pig, and Human Liver Microsomes
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Tanja Welsch, Hans-ulrich HumpfAbstract:Glucuronides of the mycoToxin T-2 Toxin and its phase I Metabolite HT-2 Toxin are important phase II Metabolites under in vivo and in vitro conditions. Since standard substances are essential for the direct quantitation of these glucuronides, a method for the enzymatic synthesis of T-2 and HT-2 Toxin glucuronides employing liver microsomes was optimized. Structure elucidation by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry revealed that besides T-2 Toxin glucuronide and HT-2 Toxin 3-glucuronide also the newly identified isomer HT-2 Toxin 4-glucuronide was formed. Glucuronidation of T-2 and HT-2 Toxin in liver microsomes of rat, mouse, pig, and human was compared and Metabolites were analyzed directly by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). A distinct, species specific pattern of glucuronidation of T-2 and HT-2 Toxin was observed with interesting interindividual differences. Until recently, glucuronides have frequently been analyzed indirectly by qu...
Miso Nam - One of the best experts on this subject based on the ideXlab platform.
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Metabolic alterations in the bone tissues of aged osteoporotic mice
Scientific Reports, 2018Co-Authors: Miso Nam, Jeong-eun Huh, Min-sun Kim, Do Hyun Ryu, Jihyeong Park, Han-sung Kim, Soo Young Lee, Geum-sook HwangAbstract:Age-related osteoporosis is characterized by reduced bone mineralization and reduced bone strength, which increases the risk of fractures. We examined metabolic changes associated with age-related bone loss by profiling lipids and polar Metabolites in tibia and femur bone tissues from young (5 months old) and old (28 months old) male C57BL/6J mice using ultra-performance liquid chromatography quadrupole-time-of-flight mass spectrometry. Partial least-squares discriminant analysis showed clear differences in Metabolite levels in bone tissues of young and old mice. We identified 93 lipid species, including free fatty acids, sphingolipids, phospholipids, and glycerolipids, that were significantly altered in bone tissues of old mice. In addition, the expression of 26 polar Metabolites differed significantly in bone tissues of old mice and young mice. Specifically, uremic Toxin Metabolite levels (p-cresyl sulfate, hippuric acid, and indoxylsulfate) were higher in bone tissues of old mice than in young mice. The increase in p-cresyl sulfate, hippuric acid, and indoxylsulfate levels were determined using targeted analysis of plasma polar extracts to determine whether these Metabolites could serve as potential osteoporosis biomarkers. This study demonstrates that LC-MS-based global profiling of lipid and polar Metabolites can elucidate metabolic changes that occur during age-related bone loss and identify potential biomarkers of osteoporosis.
A.k. Gupta - One of the best experts on this subject based on the ideXlab platform.
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Acute Toxicity of SyntheticGymnodinium breveToxin Metabolite and Its Analogues in Mice
Ecotoxicology and Environmental Safety, 1996Co-Authors: K. Husain, R. Singh, M.p. Kaushik, A.k. GuptaAbstract:Abstract Acute toxicity of synthetic Gymnodinium breve Toxin Metabolite and its analogues has been investigated in mice. The anticholinesterase potencies of the Toxin Metabolite and its analogues were determined in vitro as well as in vivo. The intraperitoneal LD 50 of the parent Metabolite O,O -dipropyl( E )-2-(1-methyl-2-oxopropylidene)phosphorohydrazidothioate( E )oxime in mice was higher compared to LD 50 values of its analogues. The in vitro acetylcholinesterase (AChE)-inhibiting potency values were higher for diethoxy(P=O) analogue than for diispropoxy(P=O) analogue. Lethal doses of parent Metabolite and its analogues significantly inhibited AChE activity in the blood and brain of mice 1 hr postexposure. The maximum inhibition by the parent Metabolite was observed in both tissues. The percentage inhibition of AChE activity was greater in the blood than in the brain. The results indicate that these agents have anticholinesterase action specifically in the blood. In conclusion, the parent Toxin Metabolite is a more potent inhibitor of AChE in vivo, whereas higher toxicity is associated with other analogues, suggesting the involvement of other factors influencing the toxicity, which needs to be further investigated.