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The castration of stallions is traditionally performed after puberty, at around the age of 2 years old. No studies have focused on the effects of early castration on osteoarticular metabolism. Thus, we aimed to compare early castration (3 days after birth) with traditional castration (18 months of age) in horses. Testosterone and estradiol levels were monitored from birth to 33 months in both groups. We quantified the levels of biomarkers of cartilage and bone anabolism (CPII and N-MID) and catabolism (CTX-I and CTX-II), as well as of osteoarthritis (HA and COMP) and inflammation (IL-6 and PGE2). We observed a lack of parallelism between testosterone and estradiol synthesis after birth and during puberty in both groups. The extra-gonadal synthesis of steroids was observed around the 28-month mark, regardless of the castration age. We found the expression of estrogen receptor (ESR1) in cartilage and bone, whereas androgen receptor (AR) expression appeared to be restricted to bone. Nevertheless, with respect to osteoarticular metabolism, steroid hormone deprivation resulting from early castration had no discernable impact on the levels of biomarkers related to bone and cartilage metabolism, nor on those associated with OA and inflammation. Consequently, our research demonstrated that early castration does not disrupt bone and cartilage homeostasis. [ABSTRACT FROM AUTHOR]

Tris (1-chloro-2-propyl) phosphate (TCIPP) is one of the major organophosphate flame retardants present in the indoor and outdoor environment. Knowledge of biotransformation pathways is important to elucidate potential bioavailability and toxicity of TCIPP and to identify relevant biomarkers. This study aimed to identify TCIPP metabolites through in vitro human metabolism assays and finally to confirm these findings in urine samples from an occupationally exposed population to propose new biomarkers to accurately monitor exposure to TCIPP.TCIPP was incubated with human liver microsomes and human liver cytosol to identify Phase I and Phase II metabolites, by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Using a suspect-screening approach, the established biomarkers bis (1-chloro-2-propyl) hydrogen phosphate (BCIPP) and 1-hydroxy-2-propyl bis (1-chloro-2-propyl) phosphate (BCIPHIPP) were identified. In addition, carboxyethyl bis (1-chloro-2-propyl) phosphate (TCIPP-M1), bis (1-chloropropan-2-yl) (-oxopropan-2-yl) phosphate (TCIPP-M2) and 1-chloro-3-hydroxypropan-2-yl bis (1-chloropropan-2-yl) phosphate (TCIPP-M3) were identified. TCIPP-M2, an intermediate product, was not reported before in literature. In urine samples, apart from BCIPP and BCIPHIPP, TCIPP-M1 and TCIPP-M3 were identified for the first time. Interestingly, BCIPP showed the lowest detection frequency, likely due to the poor sensitivity for this compound. Therefore, TCIPP-M1 and TCIPP-M3 could serve as potential additional biomarkers to more efficiently monitor TCIPP exposure in humans.

Purpose: Dopamine transporter (DAT) is a promising target for positron emission tomography (PET) imaging of many neuropsychiatric diseases. 18F-labelled N-alkyl tropane analogues were reported to be useful PET radioligands for DAT. However, the drawback of 18F-labelled tropane analogues is that N-alkyl on tropane is easily metabolized in vivo, which interferes with brain imaging. To develop a more in vivo stable DAT-targeted PET radioligand with high DAT affinity and specificity, in this study, we synthesized and compared a series of 18F-labelled novel deuterated N-fluoropropyl tropane derivatives [18F]4a-e for DAT tracing. Procedures: Five deuterated N-fluoropropyl-d6 tropane derivatives (4a-e) and corresponding non-deuterated compounds (6a-e) were synthesized, and their semi-inhibitory concentrations (IC50) were measured by competitive binding assay. The radioligands [18F]4a-e and [18F]6a-e were obtained by two-step one-pot radio-labelling reactions. The selectivity and specificity of these radioligands were evaluated by cellular uptake and microPET in normal rats. [18F]4e was selected for further investigation with microPET of the PD model, autoradiography and biodistribution experiments and compared with its non-deuterated [18F]6e. Finally, in vivo metabolic stability was analyzed by radio-HPLC. Results: Ten tropane compounds had high DAT affinity (IC50 = 2–21 nM), in which FP-CIT-d6 (4e) had the lowest IC50 value of 2.7 nM. Radiolabelled [18F]4a-e and [18F]6a-e were obtained with radiochemical yields ranging from 10.6 ± 2.8% to 35.1 ± 5.4% with molar activities >20 GBq/μmol and the radiochemical purities >99%. [18F]4e showed the highest cell uptake (12%) and CFT inhibition efficacy (∼72%) among [18F]4a-e. MicroPET results showed [18F]4e has the highest target to non-target ratio (striatum/cerebellum). Therefore, [18F]4e was then selected for further biological evaluation. Ex vivo autoradiography experiment confirmed high specific binding of [18F]4e towards DAT. Biodistribution results indicated that [18F]4e has a higher striatum/cerebellum value than [18F]FP-CIT ([18F]6e) at 30–120 min. Furthermore, in vivo metabolism studies in rats revealed improved stability of [18F]4e as compared with that of [18F]6e. Conclusions: The new probe [18F]4e is a promising candidate with good DAT affinity, specificity and metabolic stability for PET imaging, and might provide reliable diagnosis, treatment and prognostic detection of DAT-related neuropsychiatric diseases.

Copyright of Forensic Science & Technology is the property of Institute of Forensic Science, Ministry of Public Security and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/Aim: 1,5-Anhydro-D-fructose (1,5-AF, saccharide) and 1,5-anhydro-D-glucitol (1,5-AG) converted from 1,5-AF via the glycemic pathway have health benefits. However, this metabolism has not been sufficiently elucidated. To clarify the in vivo metabolism of 1,5-AF to 1,5-AG, porcine (blood kinetics) and human (urinary excretion) studies were conducted. Materials and Methods: Microminipigs were administrated 1,5-AF orally or intravenously. Blood samples were obtained to analyse the kinetics of 1,5-AF and 1,5-AG. Urine samples were collected from human subjects who had orally ingested 1,5-AF, and the amounts of 1,5-AF and 1,5-AG excreted in the urine were analysed. Results: In blood kinetics analysis, the time to the maximum concentration of 1,5-AF after intravenous administration was 0.5 h, whereas 1,5-AF was not observed after oral administration. The times to the maximum concentration of 1,5-AG after intravenous and oral administration were 1.5 h and 2 h, respectively. In urinary excretion, the concentration of 1,5-AG in urine rapidly increased after the administration of 1,5-AF, peaked at 2 h, whereas 1,5-AF was not detected. Conclusion: 1,5-AF was rapidly metabolized to 1.5-AG in vivo in swine and human. [ABSTRACT FROM AUTHOR]

CHF6366, a dual action β2-receptor agonist and M3-muscarinic receptor antagonist developed for chronic obstructive pulmonary disease (COPD) was [14C]-radiolabelled on the two different functional moieties of the molecule (either aminobutanolic or carbamate) to characterise its ADME profile following intravenous (IV), intratracheal (IT) and oral (PO) administration. A very low oral bioavailability and a good balance between absorption and lung retention after IT administration were observed, together with a rapid distribution throughout the body and a complete metabolic transformation of the parent drug without relevant gender difference. CHF6366 was observed fully hydrolysed to alcohol (CHF6387) and carboxylic acid (CHF6361) in plasma and urine after IV and IT administration, and mainly unchanged in faeces only after oral administration. An important number of metabolites containing aminobutanolic moiety was excreted via urine, whereas carbamate-containing derivatives were excreted mainly by bile. The major metabolic routes of the alcoholic moiety (CHF6387) included isomerisation (Ma7), conjugation with glucuronic acid and dehydrogenation, while the carboxylic acid moiety (CHF6361) was mainly metabolised through oxidation, glucuronide conjugation and, in both pathways, combinations of those metabolic reactions. No major differences arose also from in vitro metabolism profiles investigated using liver microsomes and hepatocytes of different species. [ABSTRACT FROM AUTHOR]

Mori Fructus (MF) is a famous edible fruit of Morus alba L. as well as traditional Chinese medicine (TCM). Moreover, exposure behavior of complex components in vivo is a necessary way to elucidate active substances in TCMs. However, the effective discovery of active ingredients from MF in vivo is still a challenge for researchers. In this study, an integrated strategy with chemical characterization, in vivo metabolism, chemical isolation, and activity evaluation was established and applied in targeted discovery of potential lipid-lowering substances in MF. First, an ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry method was established to characterize various chemical components in MF extract. Second, with the automatic matching (in-house database), discriminant ions analysis and metabolite software prediction, the metabolic profiling of different types of MF was elucidated in vivo. And the compounds from MF with high MS response in vivo were discovered. Third, according to LC-MS information of fractions, these compounds were isolated and identified by NMR. Finally, the isolated compounds were evaluated for the lipid-lowering activity on determination of triglyceride levels in high fructose-induced HepG2 cells at different concentrations. And PCSK9 inhibitory and LDL-R promoting activity were measured by western blot experiment. As a result, a total of 72 constituents were characterized in MF. After oral administration of MF extract, 16 prototypes and 33 metabolites were rapidly screened out. And the metabolism features of alkaloids, flavonols and organic acids were further revealed. Six alkaloids (morusimic acid A-D, G, F), with high MS response in vivo and no reference standards on the market, were isolated guided by LC-MS and identified by NMR. Among them, morusimic acid A, B, G and F could reduce triglyceride levels in fructose-induced HepG2 cells. Moreover, with western blot experiment, morusimic acid A, B, G and F could inhibit the expression of PCSK9 protein. And morusimic acid A, B and F could increase the expression of LDL-R protein. This work provides meaningful information for the discovery of potential compounds in MF for the treatment of obesity and hyperlipidemia, along with a new approach for exploring effective compounds from complex systems.

The castration of stallions is traditionally performed after puberty, at around the age of 2 years old. No studies have focused on the effects of early castration on osteoarticular metabolism. Thus, we aimed to compare early castration (3 days after birth) with traditional castration (18 months of age) in horses. Testosterone and estradiol levels were monitored from birth to 33 months in both groups. We quantified the levels of biomarkers of cartilage and bone anabolism (CPII and N-MID) and catabolism (CTX-I and CTX-II), as well as of osteoarthritis (HA and COMP) and inflammation (IL-6 and PGE2). We observed a lack of parallelism between testosterone and estradiol synthesis after birth and during puberty in both groups. The extra-gonadal synthesis of steroids was observed around the 28-month mark, regardless of the castration age. We found the expression of estrogen receptor (ESR1) in cartilage and bone, whereas androgen receptor (AR) expression appeared to be restricted to bone. Nevertheless, with respect to osteoarticular metabolism, steroid hormone deprivation resulting from early castration had no discernable impact on the levels of biomarkers related to bone and cartilage metabolism, nor on those associated with OA and inflammation. Consequently, our research demonstrated that early castration does not disrupt bone and cartilage homeostasis.

Nardosinone, a sesquiterpene peroxide, is one of the main active constituents of the ethnomedicine Nardostachyos Radix et Rhizoma, and it has many bioactivities, such as antiarrhythmia and cardioprotection. To elucidate its in vivo existence forms, its metabolism is first studied using mice. All urine and feces are collected during the six days of oral dosing of nardosinone, and blood is collected at one hour after the last dose. Besides, to validate some metabolites, a fast experiment is performed, in which nardosinone was orally administered and the subsequent one-hour urine is collected and immediately analyzed by UHPLC-Q-TOF-MS. In total, 76 new metabolites are identified in this study, including 39, 51, and 12 metabolites in urine, plasma, and feces, respectively. Nardosinone can be converted into nardosinone acid or its isomers. The metabolic reactions of nardosinone included hydroxylation, hydrogenation, dehydration, glucuronidation, sulfation, demethylation, and carboxylation. There are 56 and 20 metabolites with the structural skeleton of nardosinone and nardosinone acid, respectively. In total, 77 in vivo existence forms of nardosinone are found in mice. Nardosinone is mainly excreted in urine and is not detected in the feces. These findings will lay the foundation for further research of the in vivo effective forms of nardosinone and Nardostachyos Radix et Rhizoma. [ABSTRACT FROM AUTHOR]

Objective: Paeoniae Radix Rubra (PRR) is a commonly used traditional Chinese medicine with the effects of clearing away heat, cooling the blood, and relieving blood stasis. To 1) elucidate the metabolites and metabolic pathways of PRR and its 14 main constituents in mice and 2) reveal the possible origins of the known effective forms of PRR and their isomers, the metabolism of PRR in mice was systematically studied for the first time. Methods: PRR and its 14 constituents were administered to mice by gavage once a day for seven consecutive days, respectively. All urine and feces were collected during the 7 days of dosing, and blood was collected at 1 h after the last dose. Metabolites were detected and identified using high performance liquid chromatography with diode array detector and combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry (HPLC-DAD-ESI-IT-TOF-MSn). Results: In total, 23, 16, 24, 17, 18, 30, 27, 17, 22, 17, 33, 3, 8, 24, and 31 metabolites of paeoniflorin, albiflorin, oxypaeoniflorin, benzoylpaeoniflorin, hydroxybenzoylpaeoniflorin, benzoyloxypaeoniflorin, galloylpaeoniflorin, lactiflorin, epicatechin gallate, catechin gallate, catechin, ellagic acid, 3,3'-di-O-methylellagic acid, methylgallate, and PRR were respectively identified in mice; after eliminating identical metabolites, a total of 195 metabolites remained, including 8, 11, 25, 17, 18, 30, 27, 17, 21, 17, 1, 2, 8, 20, and 20 newly identified metabolites, respectively. The metabolic reactions of PRR and its 14 main constituents in mice were primarily methylation, hydrogenation, hydrolysis, hydroxylation, glucuronidation, and sulfation. Conclusion: We elucidated the metabolites and metabolic pathways of PRR and its 14 constituents (e.g., paeoniflorin, catechin, ellagic acid, and gallic acid) in mice and revealed the possible origins of the 10 known effective forms of PRR and their isomers. The findings are of great significance to studying the mechanism of action and quality control of PRR. [ABSTRACT FROM AUTHOR]

The cyclic nucleotide phosphodiesterase 2A is an intracellular enzyme which hydrolyzes the secondary messengers cAMP and cGMP and therefore plays an important role in signaling cascades. A high expression in distinct brain areas as well as in cancer cells makes PDE2A an interesting therapeutic and diagnostic target for neurodegenerative and neuropsychiatric diseases as well as for cancer. Aiming at specific imaging of this enzyme in the brain with positron emission tomography (PET), a new triazolopyridopyrazine-based derivative (11) was identified as a potent PDE2A inhibitor (IC50, PDE2A = 1.99 nM; IC50, PDE10A ~2000 nM) and has been radiofluorinated for biological evaluation. In vitro autoradiographic studies revealed that [18F]11 binds with high affinity and excellent specificity towards PDE2A in the rat brain. For the PDE2A-rich region nucleus caudate and putamen an apparent KD value of 0.24 nM and an apparent Bmax value of 16 pmol/mg protein were estimated. In vivo PET-MR studies in rats showed a moderate brain uptake of [18F]11 with a highest standardized uptake value (SUV) of 0.97. However, no considerable enrichment in PDE2A-specific regions in comparison to a reference region was detectable (SUVcaudate putamen = 0.51 vs. SUVcerebellum = 0.40 at 15 min p.i.). Furthermore, metabolism studies revealed a considerable uptake of radiometabolites of [18F]11 in the brain (66% parent fraction at 30 min p.i.). Altogether, despite the low specificity and the blood–brain barrier crossing of radiometabolites observed in vivo, [18F]11 is a valuable imaging probe for the in vitro investigation of PDE2A in the brain and has potential as a lead compound for further development of a PDE2A-specific PET ligand for neuroimaging. [ABSTRACT FROM AUTHOR]

Deciphering the metabolites of multiple components in herbal medicine has far-reaching significance for revealing pharmacodynamic ingredients. However, most chemical components of herbal medicine are secondary metabolites with low content whose in vivo metabolites are close to trace amounts, making it difficult to achieve comprehensive detection and identification. In this paper, an efficient strategy was proposed: herb-derived metabolites were predicted according to the structural characteristics and metabolic reactions of chemical constituents in Corydalis Rhizoma and chemical structure screening tables for metabolites were conducted. The fragmentation patterns were summarized from representative standards combining with specific cleavage behaviors to deduce structures of metabolites. Ion abundance plays an important role in compound identification, and high ion abundance can improve identification accuracy. The types of metabolites in different biological samples were very similar, but their ion abundance might be different. Therefore, for trace metabolites in biological samples, we used the following two methods to process: metabolites of high dose herbal extract were analyzed to characterize those of clinical dose herbal extracts in the same biological samples; cross-mapping of different biological samples was applied to identify trace metabolites based on the fact that a metabolite has different ion abundance in different biological samples. Compared with not using this strategy, 44 more metabolites of clinical dose herbal extract were detected. This study improved the depth, breadth, and accuracy of current methods for herb-derived metabolites characterization.

Prostate cancer (PCa) is the most common malignant tumor in the male reproductive system. Prostate specific membrane antigen (PSMA) is an effective target for the diagnosis and treatment of prostate cancer. The anti-PSMA small molecule/polypeptide/monoclonal antibody labeled with the therapeutic nuclides 177Lu/90Y has shown important anti-tumor activity, but it also produces specific uptake of glands, bone marrow and kidneys, which leads to normal organs' damage. In addition, small molecules/peptides are easy to be cleared by the circulatory system. Radionuclide targeted therapy based on small molecules/peptides often requires high doses or frequent administration, which leads to unpredictable organ toxicity while inhibiting tumors. Radionuclide targeted therapy relies on the delivery of radionuclides to tumor-expressed receptors, but the binding capacity of ligands to receptors is limited. In order to improve the use efficiency of radionuclides, prolong the metabolism of radionuclide therapeutic PSMA molecular probes as well as increase the ratio of target to non target, great progress has been made in the study of functional modification of PSMA molecular probes which can improve the pharmacokinetic behavior. In this paper, we summarize the recent clinical translation and clinical research of functional nuclide targeting PSMA molecular probe in the treatment of prostate cancer.

Γ-Valero-lactone (GVL) is a freely marketed organic solvent and food additive. GVL is also an underrated legal substitute for γ-hydroxybutyric acid (GHB), and it is sold under the trade name ''Tranquili-G''. GVL is usually not included in forensic drug testing, even though it has been reported in drug-facilitated sexual assaults (DFSA).To date, few studies verified the effectiveness of GVL as a hypnotic/narcotic substance, and no data are available on its urinary excretion profile. This work aims to fill this knowledge gap and lead to the introduction of GVL in forensic drug testing, especially when DFSA is suspected.To monitor the timeframe of GVL activity in vivo, we have assessed the effects on sensorimotor responses in visual placing tests carried out on CD-1 mice at a dose of 400 mg/kg of GVL, administered by gastric gavage. In parallel, samples of the in vitro and in vivo metabolism studies were analyzed using a rapid and cost-effective analytical procedure based on gas chromatography coupled to mass spectrometry. Our data confirmed that GVL impairs visual placing response in mice in the first 4 h after the intake, and they also show that GVL is a less potent substitute of GHB. The urinary excretion profile of GVL is consistent with the results of the behavioral study, with a maximum of excretion in the first 5 h after the intake. GVL is only detectable in the first 0–8 h after the intake. Our data confirmed the same rapid urinary excretion rate of GHB in urine and the related forensic implications, with the risk of possible false-negative results, especially when DFSA is suspected.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nardosinone, a sesquiterpene peroxide, is one of the main active constituents of the ethnomedicine Nardostachyos Radix et Rhizoma, and it has many bioactivities, such as antiarrhythmia and cardioprotection. To elucidate its in vivo existence forms, its metabolism is first studied using mice. All urine and feces are collected during the six days of oral dosing of nardosinone, and blood is collected at one hour after the last dose. Besides, to validate some metabolites, a fast experiment is performed, in which nardosinone was orally administered and the subsequent one-hour urine is collected and immediately analyzed by UHPLC-Q-TOF-MS. In total, 76 new metabolites are identified in this study, including 39, 51, and 12 metabolites in urine, plasma, and feces, respectively. Nardosinone can be converted into nardosinone acid or its isomers. The metabolic reactions of nardosinone included hydroxylation, hydrogenation, dehydration, glucuronidation, sulfation, demethylation, and carboxylation. There are 56 and 20 metabolites with the structural skeleton of nardosinone and nardosinone acid, respectively. In total, 77 in vivo existence forms of nardosinone are found in mice. Nardosinone is mainly excreted in urine and is not detected in the feces. These findings will lay the foundation for further research of the in vivo effective forms of nardosinone and Nardostachyos Radix et Rhizoma.

The cyclic nucleotide phosphodiesterase 2A is an intracellular enzyme which hydrolyzes the secondary messengers cAMP and cGMP and therefore plays an important role in signaling cascades. A high expression in distinct brain areas as well as in cancer cells makes PDE2A an interesting therapeutic and diagnostic target for neurodegenerative and neuropsychiatric diseases as well as for cancer. Aiming at specific imaging of this enzyme in the brain with positron emission tomography (PET), a new triazolopyridopyrazine-based derivative (11) was identified as a potent PDE2A inhibitor (IC50, PDE2A = 1.99 nM; IC50, PDE10A ~2000 nM) and has been radiofluorinated for biological evaluation. In vitro autoradiographic studies revealed that [18F]11 binds with high affinity and excellent specificity towards PDE2A in the rat brain. For the PDE2A-rich region nucleus caudate and putamen an apparent KD value of 0.24 nM and an apparent Bmax value of 16 pmol/mg protein were estimated. In vivo PET-MR studies in rats showed a moderate brain uptake of [18F]11 with a highest standardized uptake value (SUV) of 0.97. However, no considerable enrichment in PDE2A-specific regions in comparison to a reference region was detectable (SUVcaudate putamen = 0.51 vs. SUVcerebellum = 0.40 at 15 min p.i.). Furthermore, metabolism studies revealed a considerable uptake of radiometabolites of [18F]11 in the brain (66% parent fraction at 30 min p.i.). Altogether, despite the low specificity and the blood–brain barrier crossing of radiometabolites observed in vivo, [18F]11 is a valuable imaging probe for the in vitro investigation of PDE2A in the brain and has potential as a lead compound for further development of a PDE2A-specific PET ligand for neuroimaging.

Deciphering the metabolites of multiple components in herbal medicine has far-reaching significance for revealing pharmacodynamic ingredients. However, most chemical components of herbal medicine are secondary metabolites with low content whose in vivo metabolites are close to trace amounts, making it difficult to achieve comprehensive detection and identification. In this paper, an efficient strategy was proposed: herb-derived metabolites were predicted according to the structural characteristics and metabolic reactions of chemical constituents in Corydalis Rhizoma and chemical structure screening tables for metabolites were conducted. The fragmentation patterns were summarized from representative standards combining with specific cleavage behaviors to deduce structures of metabolites. Ion abundance plays an important role in compound identification, and high ion abundance can improve identification accuracy. The types of metabolites in different biological samples were very similar, but their ion abundance might be different. Therefore, for trace metabolites in biological samples, we used the following two methods to process: metabolites of high dose herbal extract were analyzed to characterize those of clinical dose herbal extracts in the same biological samples; cross-mapping of different biological samples was applied to identify trace metabolites based on the fact that a metabolite has different ion abundance in different biological samples. Compared with not using this strategy, 44 more metabolites of clinical dose herbal extract were detected. This study improved the depth, breadth, and accuracy of current methods for herb-derived metabolites characterization. [Display omitted] • Cross-mapping of different doses and samples was used to detect trace herb-derived metabolites. • Herb-derived metabolites were predicted by chemical structure screening tables, which were conducted according to structural characteristics and metabolic reactions. • The metabolic characteristic fragments (MCFs) were proposed to filter structure types of metabolites. • The relationship between structure and metabolism of Yanhusuo alkaloids was demonstrated. [ABSTRACT FROM AUTHOR]

Xingbei Zhike granule (XBZK), a widely prescribed Chinese patent medicine, is known for its efficacy in clearing lung qi, relieving cough and reducing phlegm, as well as fever, dry and bitter taste, and irritability. Despite its clinical popularity, comprehensive investigations into its chemical composition, in vivo metabolism, and pharmacokinetic characteristics are limited. This study investigates the chemical composition, in vivo metabolism, and in vivo dynamics of XBZK to clarify its material basis and pharmacokinetic characteristics. Ultra-high performance liquid chromatography with Orbitrap tandem mass spectrometry (UPLC-Orbitrap-MS) was used to determine the chemical composition and in vivo metabolic profile of XBZK. Additionally, UPLC with triple quadrupole mass spectrometry (UPLC-TQ-MS/MS) was performed to quantify its main components and evaluate its in vivo dynamics in rat plasma. In total, 57 components were identified in XBZK. Furthermore, 40 prototype components and 31 metabolites were detected in various biological matrices of rats, including plasma, tissues, bile, feces, and urine. After administration, the area under the curve (AUC) for ephedrine (Eph), pseudoephedrine (Peph), neotuberostemonine (Neo), amygdalin (Amy), and enoxolone (Eno) exhibited a strong linear relationship with the administered dose (r > 0.9) in all rats. And gender-related differences in the absorption of peiminine (Pmn), peimisine (Pms), and chrysin-7- O -glucuronide (Cog) were notable among rats, with male rats showing a dose-dependent pattern of absorption, while female rats exhibited minimal absorption. XBZK contains 57 components, primarily composed of flavonoids, alkaloids, and coumarins. The eight main components were rapidly absorbed and eliminated, with some, such as Eph, Peph, Neo, Amy and Eno, following a linear pharmacokinetic pattern. Furthermore, Pmn, Pms and Cog were well absorbed in male rats, showing a dose-dependent behavior. [Display omitted] [ABSTRACT FROM AUTHOR]

Since the approval of three 18F labeled β-amyloid-targeting PET imaging agents, Amyvid (florbetapir f18, AV-45), Neuraceq (florbetaben f18, AV-1) and Vizamyl (flutemetamol f18, F-PIB), they have increasingly been employed to assist differential diagnosis of Alzheimer's disease in patients with dementia. Also, they are frequently used in selecting patients participating drug trials aiming to reduce β-amyloid (Aβ) plaques in the brain. The first approved tracer in this class was [18F]AV-45, which is metabolized rapidly in blood and some of its N -demethylated metabolites cross the blood brain barrier and resulted in lowering the image contrast. To improve metabolic stability of [18F]AV-45, we hypothesized that substituting N-CH 3 with N-CD 3 at the metabolically labile position, creating [18F]D3FSP, may reduce in vivo N -demethylation. We report the preclinical evaluation of [18F]D3FSP as an Aβ imaging agent. Preclinical pharmacology of [18F]D3FSP was evaluated using in vitro autoradiography and competitive binding assay. Biodistribution of [18F]D3FSP was evaluated in wild-type CD-1 mice. In vivo metabolism in mice and in vitro microsomal metabolism were analyzed by HPLC. Single dose acute toxicity of D3FSP was also performed in rats. [18F]D3FSP showed high binding affinity to β-amyloid plaques (Ki = 3.44 ± 1.22 nM, a value similar as AV-45 (Ki = 4.02 ± 0.22 nM)), and displayed excellent β-amyloid binding in AD brain sections consistent with known Aβ regional distribution. After an iv injection it exhibited good initial brain uptake and fast washout in wild-type CD-1 mice. In vitro microsomal metabolism and in vivo metabolism in mice did not result in any significant differences between [18F]D3FSP and [18F]AV-45. No treatment-related mortality or any adverse effects were observed in single dose acute toxicity studies administered at hundred-folds of maximum human dose. A new small molecule, [18F]D3FSP, was prepared and tested as an alternative to [18F]AV-45 to reduce N -demethylation in vivo. This strategy did not lead to better in vivo stability. However, [18F]D3FSP displayed very similar Aβ targeting property comparable to [18F]AV-45. Preclinical studies suggest that [18F]D3FSP is useful as a β-amyloid-targeting PET imaging agent. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to identify in vivo phase I metabolites of five psychoactive substances: N-ethylpentylone, ethylone, methylone, α-PVP and 4-CDC, using the in house developed experimental set-up zebrafish (Danio rerio) water tank (ZWT). High-resolution mass spectrometry allowed for metabolite identification. A pilot study of reference standard collection of N-ethylpentylone from the water tank was conducted. Methods: ZWT consisted in 8 fish placed in a 200 mL recipient-containing water for a single cathinone. Experiments were performed in triplicate. Water tank samples were collected after 8 h and pretreated through solid-phase extraction. Separation and accurate-mass spectra of metabolites were obtained using liquid chromatography–high resolution tandem mass spectrometry. Results: Phase I metabolites of α-PVP were identified, which were formed involving ketone reduction, hydroxylation, and 2″-oxo-pyrrolidine formation. The lactam derivative was the major metabolite observed for α-PVP in ZWT. N-Ethylpentylone and ethylone were transformed into phase I metabolites involving reduction, hydroxylation, and dealkylation. 4-CDC was transformed into phase I metabolites, reported for the first time, involving N-dealkylation, N,N-bis-dealkylation and reduction of the ketone group, the last one being the most intense after 8 h of the experiment. Conclusions: ZWT model indicated to be very useful to study the metabolism of the synthetic cathinones, such as N-ethylpentylone, ethylone, α-PVP and 4-CDC. Methylone seems to be a potent CYP450 inhibitor in zebrafish. More experiments are needed to better evaluate this issue. Finally, this approach was quite simple, straightforward, extremely low cost, and fast for "human-like" metabolic studies of synthetic cathinones. [ABSTRACT FROM AUTHOR]

Tris (1-chloro-2-propyl) phosphate (TCIPP) is one of the major organophosphate flame retardants present in the indoor and outdoor environment. Knowledge of biotransformation pathways is important to elucidate potential bioavailability and toxicity of TCIPP and to identify relevant biomarkers. This study aimed to identify TCIPP metabolites through in vitro human metabolism assays and finally to confirm these findings in urine samples from an occupationally exposed population to propose new biomarkers to accurately monitor exposure to TCIPP. TCIPP was incubated with human liver microsomes and human liver cytosol to identify Phase I and Phase II metabolites, by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Using a suspect-screening approach, the established biomarkers bis (1-chloro-2-propyl) hydrogen phosphate (BCIPP) and 1-hydroxy-2-propyl bis (1-chloro-2-propyl) phosphate (BCIPHIPP) were identified. In addition, carboxyethyl bis (1-chloro-2-propyl) phosphate (TCIPP-M1), bis (1-chloropropan-2-yl) (-oxopropan-2-yl) phosphate (TCIPP-M2) and 1-chloro-3-hydroxypropan-2-yl bis (1-chloropropan-2-yl) phosphate (TCIPP-M3) were identified. TCIPP-M2, an intermediate product, was not reported before in literature. In urine samples, apart from BCIPP and BCIPHIPP, TCIPP-M1 and TCIPP-M3 were identified for the first time. Interestingly, BCIPP showed the lowest detection frequency, likely due to the poor sensitivity for this compound. Therefore, TCIPP-M1 and TCIPP-M3 could serve as potential additional biomarkers to more efficiently monitor TCIPP exposure in humans., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Abstract Masitinib (MST) is an orally administered drug that targets mast cells and macrophages, important cells for immunity, by inhibiting a limited number of tyrosine kinases. It is currently registered in Europe and USA for the treatment of mast cell tumors in dogs. AB Science announced that the European Medicines Agency has accepted a conditional marketing authorization application for MST to treat amyotrophic lateral sclerosis. In our work, we focused on studying in vivo metabolism of MST in Sprague–Dawley rats. Single oral dose of MST (33 mg kg−1) was given to Sprague–Dawley rats (kept in metabolic cages) using oral gavage. Urine was collected and filtered at 0, 6, 12, 18, 24, 48, 72 and 96 h from MST dosing. An equal amount of ACN was added to urine samples. Both organic and aqueous layers were injected into liquid chromatography-tandem mass spectrometry (LC–MS/MS) to detect in vivo phase I and phase II MST metabolites. The current work reports the identification and characterization of twenty in vivo phase I and four in vivo phase II metabolites of MST by LC–MS/MS. Phase I metabolic pathways were reduction, demethylation, hydroxylation, oxidative deamination, oxidation and N-oxide formation. Phase II metabolic pathways were the direct conjugation of MST, N-demethyl metabolites and oxidative metabolites with glucuronic acid. Part of MST dose was excreted unchanged in urine. The literature review showed no previous articles have been made on in vivo metabolism of MST or detailed structural identification of the formed in vivo phase I and phase II metabolites.

Metabolism is at the cornerstone of all cellular functions and mounting evidence of its deregulation in different diseases emphasizes the importance of a comprehensive understanding of metabolic regulation at the whole-organism level. Stable-isotope measurements are a powerful tool for probing cellular metabolism and, as a result, are increasingly used to study metabolism in in vivo settings. The additional complexity of in vivo metabolic measurements requires paying special attention to experimental design and data interpretation. Here, we review recent work where in vivo stable-isotope measurements have been used to address relevant biological questions within an in vivo context, summarize different experimental and data interpretation approaches and their limitations, and discuss future opportunities in the field. Stable-isotope measurements are increasingly used to probe mammalian-cell metabolism in vivo. The selection of stable-isotope tracer(s) and tracer administration approach is key to maximize the information extracted from in vivo measurements. Metabolic models integrating stable-isotope tracer measurements in tissues and plasma allow quantitative readouts of in vivo metabolism at the whole-organ/whole-body level to be obtained. Tissue heterogeneity and metabolic compartmentalization need to be considered during data interpretation. The development of single-cell/single-organelle metabolomic approaches will advance our understanding of in vivo metabolism. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although the mechanism of femoral head necrosis has a series of explanations such as glucocorticoids, ethanol, decompression sickness, sickle cell anemia, and genetic susceptibility, the specific pathogenesis is still unclear. OBJECTIVE: To highlight the genetics of non-traumatic femoral head necrosis by combining recent genetic studies, thus providing new treatments for the repair and reconstruction of femoral head. METHODS: A computer-based online retrieval of CNKI, Wan Fang, PubMed and Web of Science databases was performed to search the related articles published from January 2000 to April 2019. The keywords ware "non-traumatic femoral head necrosis, susceptibility genes, pathogenesis' in Chinese and English, respectively. According to the inclusion and exclusion criteria, the irrelevant and repetitive articles were excluded, and finally 49 eligible articles were included for analysis. RESULTS AND CONCLUSION: Non-traumatic femoral head necrosis is an extremely complex disease whose pathogenesis is caused by a combination of factors rather than a single genetic gene. COL2A1 genetic mutation is the high susceptibility gene to non-traumatic femoral head necrosis. High-coagulation and low-fibrinolytic state-related loci in the blood, interleukin-related gene loci in immune system and lipid-related loci become more and more important in inducing non-traumatic femoral head necrosis. With the deep understanding of human genetic technology, the accuracy of detecting susceptible genes will be continuously improved, which is conducive to the prevention, diagnosis and precise individualized treatment of non-traumatic femoral head necrosis. [ABSTRACT FROM AUTHOR]

Despite the frequent infection of agricultural crops by Alternaria spp., their toxic secondary metabolites and potential food contaminants lack comprehensive metabolic characterization. In this study, we investigated their bioavailability, metabolism, and excretion in vivo. A complex Alternaria culture extract (50 mg/kg body weight) containing 11 known toxins and the isolated lead toxin altertoxin II (0.7 mg/kg body weight) were administered per gavage to groups of 14 Sprague Dawley rats each. After 3 h and 24 h, plasma, urine and feces were collected to determine toxin recoveries. For reliable quantitation, an LC–MS/MS method for the simultaneous detection of 20 Alternaria toxins and metabolites was developed and optimized for either biological matrix. The obtained results demonstrated efficient excretion of alternariol (AOH) and its monomethyl ether (AME) via feces (> 89%) and urine (> 2.6%) after 24 h, while the majority of tenuazonic acid was recovered in urine (20 and 87% after 3 and 24 h, respectively). Moreover, modified forms of AOH and AME were identified in urine and fecal samples confirming both, mammalian phase-I (4-hydroxy-AOH) and phase-II (sulfates) biotransformation in vivo. Despite the comparably high doses, perylene quinones were recovered only at very low levels (altertoxin I, alterperylenol, < 0.06% in urine and plasma, < 5% in feces) or not at all (highly genotoxic, epoxide-holding altertoxin II, stemphyltoxin III). Interestingly, altertoxin I was detected in all matrices of rats receiving altertoxin II and suggests enzymatic de-epoxidation in vivo. In conclusion, the present study contributes valuable information to advance our understanding of the emerging Alternaria mycotoxins and their relevance on food safety. [ABSTRACT FROM AUTHOR]

Dopamine transporter (DAT) is a promising target for positron emission tomography (PET) imaging of many neuropsychiatric diseases. 18F-labelled N-alkyl tropane analogues were reported to be useful PET radioligands for DAT. However, the drawback of 18F-labelled tropane analogues is that N -alkyl on tropane is easily metabolized in vivo , which interferes with brain imaging. To develop a more in vivo stable DAT-targeted PET radioligand with high DAT affinity and specificity, in this study, we synthesized and compared a series of 18F-labelled novel deuterated N-fluoropropyl tropane derivatives [18F] 4a-e for DAT tracing. Five deuterated N-fluoropropyl-d 6 tropane derivatives (4a-e) and corresponding non-deuterated compounds (6a-e) were synthesized, and their semi-inhibitory concentrations (IC 50) were measured by competitive binding assay. The radioligands [18F] 4a-e and [18F] 6a-e were obtained by two-step one-pot radio-labelling reactions. The selectivity and specificity of these radioligands were evaluated by cellular uptake and microPET in normal rats. [18F] 4e was selected for further investigation with microPET of the PD model, autoradiography and biodistribution experiments and compared with its non-deuterated [18F] 6e. Finally, in vivo metabolic stability was analyzed by radio-HPLC. Ten tropane compounds had high DAT affinity (IC 50 = 2–21 nM), in which FP-CIT-d 6 (4e) had the lowest IC 50 value of 2.7 nM. Radiolabelled [18F] 4a-e and [18F] 6a-e were obtained with radiochemical yields ranging from 10.6 ± 2.8% to 35.1 ± 5.4% with molar activities >20 GBq/μmol and the radiochemical purities >99%. [18F] 4e showed the highest cell uptake (12%) and CFT inhibition efficacy (∼72%) among [18F] 4a-e. MicroPET results showed [18F] 4e has the highest target to non-target ratio (striatum/cerebellum). Therefore, [18F] 4e was then selected for further biological evaluation. Ex vivo autoradiography experiment confirmed high specific binding of [18F] 4e towards DAT. Biodistribution results indicated that [18F] 4e has a higher striatum/cerebellum value than [18F]FP-CIT ([18F] 6e) at 30–120 min. Furthermore, in vivo metabolism studies in rats revealed improved stability of [18F] 4e as compared with that of [18F] 6e. The new probe [18F] 4e is a promising candidate with good DAT affinity, specificity and metabolic stability for PET imaging, and might provide reliable diagnosis, treatment and prognostic detection of DAT-related neuropsychiatric diseases. [ABSTRACT FROM AUTHOR]

The diabetic heart is energetically and metabolically abnormal, with increased fatty acid oxidation and decreased glucose oxidation. One factor contributing to the metabolic dysfunction in diabetes may be abnormal handling of acetyl and acyl groups by the mitochondria. L-carnitine is responsible for their transfer across the mitochondrial membrane, therefore, supplementation with L-carnitine may provide a route to improve the metabolic state of the diabetic heart. The primary aim of this study was to use hyperpolarized magnetic resonance imaging (MRI) to investigate the effects of L-carnitine supplementation on the in vivo metabolism of [1-13C]pyruvate in diabetes. Male Wistar rats were injected with either vehicle or streptozotocin (55 mg/kg) to induce type-1 diabetes. Three weeks of daily i.p. treatment with either saline or L-carnitine (3 g/kg/day) was subsequently undertaken. In vivo cardiac function and metabolism were assessed with CINE and hyperpolarized MRI, respectively. L-carnitine supplementation prevented the progression of hyperglycemia, which was observed in untreated streptozotocin injected animals and led to reductions in plasma triglyceride and ß-hydroxybutyrate concentrations. Hyperpolarized MRI revealed that L-carnitine treatment elevated pyruvate dehydrogenase flux by 3-fold in the diabetic animals, potentially through increased buffering of excess acetyl-CoA units in the mitochondria. Improved functional recovery following ischemia was also observed in the L-carnitine treated diabetic animals.

Speciation transformation of arsenic in the abalone viscera hydrolysate fraction (AVHF) was evaluated using in vitro and in vivo methods to determine its safety given that AVHF is rich in arsenic. The dimethylarsinic acid (DMA) proportion and some free amino acid contents increased, whereas arsenobetaine (AB) proportion decreased when AVHF was digested by pepsin. However, molecular weight distribution was unchanged, and no obvious changes were found in the intestinal medium. In the single-dose experiment, the AB concentration on the mouse plasma rapidly increased, which reached up to 12.53 ng/mL in 2 h after the administration of AVHF (10 g/kg body weight) and reduced to half of the maximum at 8 h after administration. Furthermore, alanine (Ala) content in the urine of mice increased at 8 h after AVHF administration, suggesting that Ala might be chelated with arsenic and could not be absorbed well. Long-term experiments showed that AB was not accumulated in mice tissue/organ. However, some AB could be converted into DMA, which was mainly accumulated in mice hair. The in vivo experiments also suggested that the AVHF is safe as health food. Unlabelled Image • When AVHF was digested by pepsin, DMA proportion increased. • Speciation of arsenic in urine, feces and tissues of mice dosed with AVHF. • AB concentration in mice blood reached maximum at 2 h after administration of AVHF. • A portion of AB in the mice gavaged AVHF could be converted into DMA. • DMA was mainly accumulated in the hair of mice. [ABSTRACT FROM AUTHOR]

Loxoprofen is a prodrug that exerts strong analgesic and anti‐inflammatory effects through its active trans‐alcohol metabolite, which is produced in the liver by carbonyl reductase. Previous metabolic studies have evaluated loxoprofen, but its sulfate and taurine conjugates have not yet been studied. We characterized the metabolomic profile of loxoprofen in rat plasma, urine, and feces using high‐resolution mass spectrometry. We identified 17 metabolites of loxoprofen in the three different biological matrices, 13 of which were detected in plasma and feces and 16 in urine. Amongst these metabolites, two novel taurine conjugates (M12 and M13) and two novel acyl glucuronides (M14, M15) were identified for the first time in rats. In addition, we detected three novel sulfate conjugates (M9, M10, and M11) of loxoprofen. Further study of these metabolites of loxoprofen is essential in order to assess their potency and toxicity. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ecdysteroids undergo side-chain cleavage during their in vivo metabolism. • Through oxidative chemistry, several new ecdysteroid metabolites were prepared. • The new compounds were characterized with complete NMR signal assignment. • The compounds showed the ability to increase the activation of protein kinase B. • Ecdysteroids with higher degree of unsaturation showed stronger bioactivity. Abstract Phytoecdysteroids exert their non-hormonal anabolic and adaptogenic effects in mammals, including humans, through a partially revealed mechanism of action involving the activation of protein kinase B (Akt). We have recently found that poststerone, a side-chain cleaved in vivo metabolite of 20-hydroxyecdysone, exerts potent anabolic activity in rats. Here we report the semi-synthetic preparation of a series of side-chain cleaved ecdysteroids and their activity on the Akt phosphorylation in murine skeletal muscle cells. Twelve C-21 ecdysteroids including 8 new compounds were obtained through the oxidative side-chain cleavage of various phytoecdysteroids, or through the base-catalyzed autoxidation of poststerone. The complete 1H and 13C NMR spectroscopic assignments of the new compounds are presented. Among the tested compounds, 9 could activate Akt stronger than poststerone revealing that side-chain cleaved derivatives of phytoecdysteroids other than 20-hydroxyecdysone are valuable bioactive metabolites. Thus, our results suggest that the expectable in vivo formation of such compounds should contribute to the bioactivity of herbal preparations containing ecdysteroid mixtures. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • First study exposing rats to a complex Alternaria toxin mixture. • Several Alternaria toxins determined in rat urine and feces for the first time. • Excretion rates for seven toxins estimated. Abstract Alternaria mycotoxins frequently contaminate agricultural crops and may impact animal and human health. However, data on mammalian metabolism and potential biomarkers of exposure for human biomonitoring (HBM) are scarce. Here, we report the preliminary investigation with respect to metabolism and excretion of Alternaria toxins in Sprague Dawley rats. Four animals were housed in metabolic cages for 24 h after gavage administration of an Alternaria alternata culture extract containing ten known toxins. LC–MS/MS analysis of 17 Alternaria toxins in urine and fecal samples allowed to gain first insights regarding xenobiotic metabolism and excretion rates. Alternariol (6–10%), alternariol monomethyl ether (AME, 6–7%) and tenuazonic acid (up to 55%) were recovered in urine and fecal samples (9%, 87%, 0.3%, respectively), while perylene quinones administered at comparatively high levels, were either determined at very low levels (up to 0.5% altertoxin I in urine and 15% in feces; 0.2% alterperylenol in urine and 3% in feces) or not at all (altertoxin II, stemphyltoxin III). AME-3-sulfate, which was not present in the administered extract, was determined in urine, representing up to 23% of the AME intake. Critical evaluation of the applied sample preparation protocol and LC–MS/MS analysis revealed interesting preliminary results and information crucial for improving follow-up experiments. [ABSTRACT FROM AUTHOR]

Synthetic cannabinoids belong to one of the largest groups of new psychoactive substances (NPS) and are challenging regarding analytical detection because of the often complete metabolic degradation of the parent compounds. 5F-CUMYL-P7AICA contains a 7-azaindole moiety and appeared first on the market in 2015. In the frame of abstinence control cases, possible 5F-CUMYL-P7AICA metabolites were detected in three urine samples. The samples were reanalyzed using liquid-chromatography-high resolution mass spectrometry (LC-HRMS) and human phase I and II metabolites were identified. Major in vivo biotransformation steps of 5F-CUMYL-P7AICA in humans were oxidative defluorination followed by carboxylation, and monohydroxylation followed by sulfation and glucuronidation. Evaluation of the metabolites as marker for 5F-CUMYL-P7AICA consumption revealed the defluorinated and carboxylated metabolite to be important for sensitive detection. For higher specificity, additional monitoring of a monohydroxylated metabolite is recommended. Comparison with previously published in vitro metabolism data revealed good accordance of the results, with exception of a of the dihydroxylated metabolites from the in vitro assays, which were not detected in the in vivo samples. [ABSTRACT FROM AUTHOR]

Clinical failure of novel drugs is often related to their rapid metabolism and excretion. This highlights the importance of elucidation of their pharmacokinetic profile already at the preclinical stage of drug development. Triapine, the most prominent representative of α-N-heterocyclic thiosemicarbazones, was investigated in more than 30 clinical phase I/II trials, but the results against solid tumors were disappointing. Recent investigations from our group suggested that this is, at least partially, based on the fast metabolism and excretion. In order to establish more detailed structure/activity/metabolism relationships, herein a panel of 10 different Triapine derivatives was investigated for their metabolic pathways. From the biological point of view, the panel consists of terminally dimethylated thiosemicarbazones with nanomolar IC50 values, derivatives with micromolar cytotoxicities comparable to Triapine and a completely inactive representative. To study the oxidative metabolism, a purely instrumental approach based on electrochemistry/mass spectrometry was applied and the results were compared to the data obtained from microsomal incubations. Overall, the investigated thiosemicarbazones underwent the phase I metabolic reactions dehydrogenation, hydroxylation, oxidative desulfuration (to semicarbazone and amidrazone) and demethylation. Notably, dehydrogenation resulted in a ring-closure reaction with formation of thiadiazoles. Although strong differences between the metabolic pathways of the different thiosemicarbazones were observed, they could not be directly correlated to their cytotoxicities. Finally, the metabolic pathways for the most cytotoxic compound were elucidated also in tissues collected from drug-treated mice, confirming the data obtained by electrochemical oxidation and microsomes. In addition, the in vivo experiments revealed a very fast metabolism and excretion of the compound.Structure/activity/metabolisation relationships for 10 anticancer thiosemicarbazones were established using electrochemical oxidation coupled to mass spectrometry (EC-MS) and human liver microsomes analyzed by LC-MS [ABSTRACT FROM AUTHOR]

Introduction Vesicular monoamine transporters 2 (VMAT2) in the brain serve as transporter for packaging monoamine in vesicles for normal CNS neurotransmission. Several VMAT2 imaging agents, [ 11 C]-(+)-DTBZ, dihydrotetrabenazine and [ 18 F]FP-(+)-DTBZ (9-O-fluoropropyl-(+)-dihydro tetrabenazine, a.k.a. [ 18 F]AV-133), are useful for studying the changes in brain function related to monoamine transmission by in vivo imaging. Deuterated analogs have been reported targeting VMAT2 binding sites. Methods A novel deuterated [ 18 F]9-O-hexaduterofluoropropyl-(+)-dihydrotetrabenazine, [ 18 F]D6-FP-(+)-DTBZ, [ 18 F] 1 , was prepared as a VMAT2 imaging agent. This 18 F agent which targeted VMAT2 was evaluated by in vitro binding, in vivo biodistribution and microPET imaging studies in rodents. Results The one step radiolabeling reaction led to the desired [ 18 F]D6-FP-(+)-DTBZ, [ 18 F] 1 , which showed excellent binding affinity to VMAT2 (Ki = 0.32 ± 0.07 nM) comparable to that of FP-(+)-DTBZ (Ki = 0.33 ± 0.02 nM) using [ 18 F]FP-(+)-DTBZ and rat striatum membrane homogenates. In vivo biodistribution in normal rats showed that 1 , exhibited excellent brain uptake and comparable high ratio of striatum to cerebellum (target/background) ratio at 1 h after injection (ratio of 6.05 ± 0.43 vs 5.66 ± 0.72 for [ 18 F]FP-(+)-DTBZ vs [ 18 F] 1 , respectively). MicroPET imaging studies in rats further confirm that the striatum with high VMAT2 concentration was clearly delineated in normal rat brain after iv injection of [ 18 F] 1 . We observed minor changes of metabolism in rat plasma between these two agents; however, the changes showed little effect on regional brain uptake and retention. Conclusions The results reported here lend support for using [ 18 F]D6-FP-(+)-DTBZ, [ 18 F] 1 , as in vivo PET imaging agent for VMAT2 binding in the brain. [ABSTRACT FROM AUTHOR]

• An integrated strategy with chemical characterization, in vivo metabolism, chemical isolation, and activity evaluation was established and applied in targeted discovery of potential lipid-lowering substances in Mori Fructus. • Alkaloids with MS high response in vitro and in vivo were discovered by analysis of chemical characterization and in vivo metabolism of MF for the first time. • Six alkaloids (morusimic acid A-D, G, F) were isolated guided by LC-MS and identified by NMR. • Morusimic acid A, B, G and F could reduce triglyceride levels in fructose-induced HepG2 cells. • Some alkaloids could significantly down-regulate the expression of PCSK9 protein and promote the LDL-R protein. Mori Fructus (MF) is a famous edible fruit of Morus alba L. as well as traditional Chinese medicine (TCM). Moreover, exposure behavior of complex components in vivo is a necessary way to elucidate active substances in TCMs. However, the effective discovery of active ingredients from MF in vivo is still a challenge for researchers. In this study, an integrated strategy with chemical characterization, in vivo metabolism, chemical isolation, and activity evaluation was established and applied in targeted discovery of potential lipid-lowering substances in MF. First, an ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry method was established to characterize various chemical components in MF extract. Second, with the automatic matching (in-house database), discriminant ions analysis and metabolite software prediction, the metabolic profiling of different types of MF was elucidated in vivo. And the compounds from MF with high MS response in vivo were discovered. Third, according to LC-MS information of fractions, these compounds were isolated and identified by NMR. Finally, the isolated compounds were evaluated for the lipid-lowering activity on determination of triglyceride levels in high fructose-induced HepG2 cells at different concentrations. And PCSK9 inhibitory and LDL-R promoting activity were measured by western blot experiment. As a result, a total of 72 constituents were characterized in MF. After oral administration of MF extract, 16 prototypes and 33 metabolites were rapidly screened out. And the metabolism features of alkaloids, flavonols and organic acids were further revealed. Six alkaloids (morusimic acid A-D, G, F), with high MS response in vivo and no reference standards on the market, were isolated guided by LC-MS and identified by NMR. Among them, morusimic acid A, B, G and F could reduce triglyceride levels in fructose-induced HepG2 cells. Moreover, with western blot experiment, morusimic acid A, B, G and F could inhibit the expression of PCSK9 protein. And morusimic acid A, B and F could increase the expression of LDL-R protein. This work provides meaningful information for the discovery of potential compounds in MF for the treatment of obesity and hyperlipidemia, along with a new approach for exploring effective compounds from complex systems. [ABSTRACT FROM AUTHOR]

The recent appearance of APINAC (AKB-57, ACBL(N)-018, adamantan-1-yl 1-pentyl-1 H-indazole-3-carboxylate) in the market of the so-called novel psychoactive substances resulted in the need of defining its characteristics and searching its metabolites for subsequent detection in biological samples. The structure of the APINAC molecule has great similarity to the molecules of other synthetic cannabinoids. Here we report on the in vivo metabolism of APINAC using rats as an experimental model. Rat urine samples were analyzed by using gas chromatography-mass spectrometry and liquid chromatography-high resolution mass spectrometry. Data were acquired via time-of-flight mass scan, followed by Auto MS and triggered product ion scans. The predominant metabolic pathway for APINAC was ester hydrolysis yielding a wide variety of N-pentylindazole-3-carboxylic acid metabolites and 1-adamantanol metabolites. Ten metabolites for APINAC were identified, with the majority generated by hydroxylation, carbonylation, and carboxylation with or without glucuronidation. Therefore, in vivo metabolic profiles in rats were generated for APINAC. N-Pentylindazole-3-carboxylic acid, hydroxylated N-pentylindazole-3-carboxylic acid, and 1-adamantanol are likely the best targets to incorporate into analytical screening methods for drugs analysis. The presented mass spectra and retention time data may be useful for detection of these compounds in human urine. [ABSTRACT FROM AUTHOR]

Shen-Wu-Yi-Shen tablet (SWYST), a well-known traditional Chinese medicine prescription (TCMP), has been effectively used for treating chronic kidney disease (CKD) in clinically. However, an in-depth study of in vivo metabolism of SWYST is lacking. In this study, a targeted and non-targeted strategy based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) was developed to screen and characterize SWYST-related xenobiotics in rats. Based on the in-house library, a chemical database of SWYST including 215 constituents was constructed through "find by formula" and further verified by characteristic fragmentations or the literatures. Then the constructed chemical database was applied for the targeted screening of prototypes. As for metabolites, the non-targeted screening was achieved combined the peak picking using the function "find by auto-MS/MS" and peak filtration of the prototypes and endogenous components, while the targeted screening was performed using Metabolite ID according to the possible metabolic reactions. Furthermore, the potential metabolites were preliminarily identified by comparison of the parent compounds or references to the literatures. As a result, 201 exogenous components (87 prototypes and 121 metabolites) were characterized in rats after administration of SWYST, including 55 (17 prototypes and 38 metabolites) in plasma, 151 (52 prototypes and 99 metabolites) in urine, and 121 (74 prototypes and 47 metabolites) in feces. Finally, their possible metabolic pathways were summarized, and the metabolic reactions mainly involved phase I reactions (hydroxylation, deoxygenation, hydrogenation, methylation, oxidation, hydrolysis and esterification) and phase II reactions (glucuronidation and sulfation). The findings of this research reveal the potential active ingredients of SWYST, providing an important material basis for the pharmacokinetics and pharmacodynamics of SWYST. • In vivo metabolism of SWYST was first investigated combined with a targeted and non-targeted strategy. • Fragmentation pathways of the stilbene-related metabolites were systematically elucidated. • Sterone-related metabolites were reported and their possible metabolic pathways were summarized. [ABSTRACT FROM AUTHOR]

Background/aim: 1,5-Anhydro-d-fructose (1,5-AF, saccharide) and 1,5-anhydro-d-glucitol (1,5-AG) converted from 1,5-AF via the glycemic pathway have health benefits. However, this metabolism has not been sufficiently elucidated. To clarify the in vivo metabolism of 1,5-AF to 1,5-AG, porcine (blood kinetics) and human (urinary excretion) studies were conducted., Materials and Methods: Microminipigs were administrated 1,5-AF orally or intravenously. Blood samples were obtained to analyse the kinetics of 1,5-AF and 1,5-AG. Urine samples were collected from human subjects who had orally ingested 1,5-AF, and the amounts of 1,5-AF and 1,5-AG excreted in the urine were analysed., Results: In blood kinetics analysis, the time to the maximum concentration of 1,5-AF after intravenous administration was 0.5 h, whereas 1,5-AF was not observed after oral administration. The times to the maximum concentration of 1,5-AG after intravenous and oral administration were 1.5 h and 2 h, respectively. In urinary excretion, the concentration of 1,5-AG in urine rapidly increased after the administration of 1,5-AF, peaked at 2 h, whereas 1,5-AF was not detected., Conclusion: 1,5-AF was rapidly metabolized to 1.5-AG in vivo in swine and human., (Copyright © 2023, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

[Display omitted] • UHPLC-LTQ-OrbiTrap-MS/MS identified the phenolic compounds in durian shell extracts (DSE). • The metabolites and distribution of durian shell extract in rats were studied. • Durian shell extract could effectively reduce H 2 O 2 -induced oxidative damage in HepG2 cells. • Durian shell extract could inhibit apoptosis by regulating genes and proteins related to mitochondrial pathway apoptosis. Durian is a nutritious tropical fruit with potent antioxidant, anti-inflammatory, antibacterial and anti-cancer effects. However, the durian shell was mainly discarded as waste, while there were few studies on the characterization of its phenolic profiles, antioxidant activities, and in vivo metabolites. In the present study, a total of 17 compounds were identified in durian shell extract (DSE) by using an ultra-high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MS/MS), while 33 metabolites were found in rats' plasma, urine and organ. Moreover, DSE could effectively reduce H 2 O 2 -induced oxidative damage in HepG2 cells, reduce the expression of Reactive Oxygen Species (ROS), Malondialdehyde (MDA) and Lactate Dehydrogenase (LDH) and inhibit apoptosis by regulating the expression of Bcl-2-Associated X (BAX), B-Cell Lymphoma 2 (BCL-2), Caspase-3 and Caspase-9 genes and proteins related to mitochondrial pathway apoptosis. This is the first comprehensive report on Durian shell phenolics, their metabolic profiles and underlying mechanisms of the in vitro antioxidant activities. [ABSTRACT FROM AUTHOR]

Ziyuglycoside I is one of the major active ingredients in Sanguisorba officinalis , a popular medicinal plant in China. In the present study, the metabolites of ziyuglycoside I in rat liver microsome and intestinal flora were identified and structurally characterized, and the metabolic rules were summed based on the LC–Q-TOF/MS system. Then, the metabolites in rat excreta samples were rapidly screened and identified according to the in vitro metabolic rules. Finally, ziyuglycoside I was incubated with fresh liver/lung/kidney/stomach homogenates to further explore the source of the metabolites and reveal the possible metabolic organs involved. Four metabolites in liver microsome were identified as M0-Glu, M0-CH 2 OH, M0-Glu + CH 3 , M0-Glu-Ara + CH 3 . In intestinal flora incubation system, 6 degradation products including M0-Glu-Ara + O, M0-Ara, M0-Glu-COOH, M0-Glu, M0-Glu-Ara + O and M0-Ara + H 2 O were tentatively identified by interpretation of their accurate MS 1 and MS 2 data. Fifteen metabolites in rat urine and feces were identified, and most of the metabolites were attributed to the transformation in liver microsome and intestinal flora. Specifically, more than a dozen of new metabolites were identified in rat fresh tissues, and ziyuglycoside II was confirmed as the major metabolite in rats. [ABSTRACT FROM AUTHOR]