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Molecules (Basel, Switzerland) May 2023Fenebrutinib is an orally available Bruton tyrosine kinase inhibitor. It is currently in multiple phase III clinical trials for the management of B-cell tumors and...
Fenebrutinib is an orally available Bruton tyrosine kinase inhibitor. It is currently in multiple phase III clinical trials for the management of B-cell tumors and autoimmune disorders. Elementary in-silico studies were first performed to predict susceptible sites of metabolism and structural alerts for toxicities by StarDrop WhichP450™ module and DEREK software; respectively. Fenebrutinib metabolites and adducts were characterized in-vitro in rat liver microsomes (RLM) using MS3 method in Ion Trap LC-MS/MS. Formation of reactive and unstable intermediates was explored using potassium cyanide (KCN), glutathione (GSH) and methoxylamine as trapping nucleophiles to capture the transient and unstable iminium, 6-iminopyridin-3()-one and aldehyde intermediates, respectively, to generate a stable adducts that can be investigated and analyzed using mass spectrometry. Ten phase I metabolites, four cyanide adducts, five GSH adducts and six methoxylamine adducts of fenebrutinib were identified. The proposed metabolic reactions involved in formation of these metabolites are hydroxylation, oxidation of primary alcohol to aldehyde, n-oxidation, and n-dealkylation. The mechanism of reactive intermediate formation of fenebrutinib can provide a justification of the cause of its adverse effects. Formation of iminium, iminoquinone and aldehyde intermediates of fenebrutinib was characterized. N-dealkylation followed by hydroxylation of the piperazine ring is proposed to cause the bioactivation to iminium intermediates captured by cyanide. Oxidation of the hydroxymethyl group on the pyridine moiety is proposed to cause the generation of reactive aldehyde intermediates captures by methoxylamine. N-dealkylation and hydroxylation of the pyridine ring is proposed to cause formation of iminoquinone reactive intermediates captured by glutathione. FBB and several phase I metabolites are bioactivated to fifteen reactive intermediates which might be the cause of adverse effects. In the future, drug discovery experiments utilizing this information could be performed, permitting the synthesis of new drugs with better safety profile. Overall, in silico software and in vitro metabolic incubation experiments were able to characterize the FBB metabolites and reactive intermediates using the multistep fragmentation capability of ion trap mass spectrometry.
Topics: Rats; Animals; Chromatography, Liquid; Chromatography, High Pressure Liquid; Tandem Mass Spectrometry; Piperazines; Pyridones; Glutathione; Cyanides; Aldehydes; Microsomes, Liver
PubMed: 37241965
DOI: 10.3390/molecules28104225 -
Journal of Labelled Compounds &... Jun 2023A strategy has been developed for the carbon-14 radiosynthesis of [ C]-SHP-141, a 4-(7-hydroxycarbamoyl-heptanoyloxy)-benzoic acid methyl ester derivative containing a...
Nitrilase mediated mild hydrolysis of a carbon-14 nitrile for the radiosynthesis of 4-(7-hydroxycarbamoyl-[1- C-heptanoyl]-oxy)-benzoic acid methyl ester, [ C]-SHP-141: A novel class I/II histone deacetylase (HDAC) inhibitor.
A strategy has been developed for the carbon-14 radiosynthesis of [ C]-SHP-141, a 4-(7-hydroxycarbamoyl-heptanoyloxy)-benzoic acid methyl ester derivative containing a terminal hydroxamic acid. The synthesis involved four radiochemical transformations. The key step in the radiosynthesis was the conversion of the 7-[ C]-cyano-heptanoic acid benzyloxyamide [ C]-4 directly into the carboxylic acid derivative, 7-benzyloxycarbamoyl-[ C]-heptanoic acid [ C]-8 using nitrilase-113 biocatalyst. The final step involved deprotection of the benzyloxy group using catalytic hydrogenation to facilitate the release of the hydroxamic acid without cleaving the phenoxy ester. [ C]-SHP-141 was isolated with a radiochemical purity of 90% and a specific activity of 190 μCi/mg from four radiochemical steps starting from potassium [ C]-cyanide in a radiochemical yield of 45%.
Topics: Histone Deacetylase Inhibitors; Carbon Radioisotopes; Benzoic Acid; Esters; Nitriles; Hydrolysis; Hydroxamic Acids; Radiopharmaceuticals; Histone Deacetylases
PubMed: 37186406
DOI: 10.1002/jlcr.4026 -
Endocrine, Metabolic & Immune Disorders... Apr 2023To provide in vitro data on toxicity mechanisms of clozapine, diclofenac and nifedipine.
AIM
To provide in vitro data on toxicity mechanisms of clozapine, diclofenac and nifedipine.
BACKGROUND
CHO-K1 cells were used as in vitro model to explore mechanisms of cytotoxicity of the test drugs.
OBJECTIVE
Cytotoxic mechanisms of clozapine (CLZ), diclofenac (DIC) and nifedipine (NIF) were studied in CHO-K1 cells in vitro. All three drugs induce adverse reactions in some patients with partially unknown mechanisms.
METHOD
Following the determination of time- and dose-dependency of cytotoxicity by the MTT test, cytoplasmic membrane integrity was explored by the LDH leakage test. Both end-points were further examined in the presence of soft and hard nucleophilic agents, glutathione (GSH) and potassium cyanide (KCN), respectively, and either individual or general cytochrome P450 (CYP) inhibitors, whether CYP-catalysed formation of electrophilic metabolites play a role in the observed cytotoxicity and membrane damage. The generation of reactive metabolites during the incubations was also explored. Formation of malondialdehyde (MDA) and oxidation of dihydrofluorescein (DCFH) were monitored whether peroxidative membrane damage and oxidative stress take place in cytotoxicity. Incubations were also conducted in the presence of chelating agents of EDTA or DTPA to explore any possible role of metals in cytotoxicity by facilitating electron transfer in redox reactions. Finally, mitochondrial membrane oxidative degradation and permeability transition pore (mPTP) induction by the drugs were tested as markers of mitochondrial damage.
RESULTS
The presence of an individual or combined nucleophilic agents significantly diminished CLZ- and NIF-induced cytotoxicities, while the presence of both agents paradoxically increased DIC-induced cytotoxicity by a factor of three with the reason remaining unknown. The presence of GSH significantly increased DIC-induced membrane damage too. Prevention of membrane damage by the hard nucleophile KCN suggests the generation of a hard electrophile upon DIC and GSH interaction. The presence of CYP2C9 inhibitor sulfaphenazol significantly diminished DIC-induced cytotoxicity, probably by preventing the formation of 4-hydroxylated metabolite of DIC, which further converts to an electrophilic reactive intermediate. Among the chelating agents, EDTA caused a marginal decrease in CLZ-induced cytotoxicity, while DIC-induced cytotoxicity was amplified by a factor of five. Both reactive and stable metabolites of CLZ could be detected in the incubation medium of CLZ with CHO-K1 cells, which are known to have low metabolic capacity. All three drugs caused a significant increase in cytoplasmic oxidative stress by means of DCFH oxidation, which was confirmed by increased MDA from cytoplasmic as well as mitochondrial membranes. The addition of GSH paradoxically and significantly increased DIC-induced MDA formation, in parallel with the increase in membrane damage when DIC and GSH combined.
CONCLUSION
Our results suggested that the soft electrophilic nitrenium ion of CLZ is not responsible for the observed in vitro toxicities, and this may originate from a relatively low amount of the metabolite due to the low metabolic capacity of CHO-K1. A hard electrophilic intermediate may contribute to cellular membrane damage incubated with DIC, while a soft electrophilic intermediate seems to exacerbate cell death by a mechanism other than membrane damage. A significant decrease in cytotoxicity of NIF by GSH and KCN suggested that both soft and hard electrophiles contribute to NIF-induced cytotoxicity. All three drugs induced peroxidative cytoplasmic membrane damage, while only DIC and NIF induced peroxidative mitochondrial membrane damage, which suggested mitochondrial processes may contribute to adverse effects of these drugs in vivo.
PubMed: 37114786
DOI: 10.2174/1871530323666230419084613 -
The Journal of Organic Chemistry May 2023A highly diastereoselective tandem reaction of 2'-nitrochalcones is reported, involving Michael addition and a subsequent -substitution of the nitro group to produce...
A highly diastereoselective tandem reaction of 2'-nitrochalcones is reported, involving Michael addition and a subsequent -substitution of the nitro group to produce 1-tetralones with two contiguous chiral centers. A related annulation reaction of 2'-nitrochalcones with potassium cyanide affording 1-indanones with a C3-quaternary chiral center is also demonstrated.
PubMed: 37068176
DOI: 10.1021/acs.joc.3c00134 -
Organic & Biomolecular Chemistry Apr 2023A practical, one-pot approach to 3-anilino-4-(het)arylmaleimides by simple heating of aqueous DMSO solution of 2'-nitrochalcones with potassium cyanide in the presence...
A practical, one-pot approach to 3-anilino-4-(het)arylmaleimides by simple heating of aqueous DMSO solution of 2'-nitrochalcones with potassium cyanide in the presence of formic acid has been developed. This new reaction provides effective access to a variety of β-substituted α-aminomaleimides which have recently become a subject of growing interest as small, easily modified and environmentally responsive fluorescent probes.
PubMed: 36945887
DOI: 10.1039/d3ob00197k -
ChemPlusChem Apr 2023Invited for this month's cover is the group of Prof. Dr. Christian Müller from Freie Universität Berlin, Germany. The cover picture shows a phosphinine selenide that...
Invited for this month's cover is the group of Prof. Dr. Christian Müller from Freie Universität Berlin, Germany. The cover picture shows a phosphinine selenide that interacts with organoiodines and halogens to form co-crystalline and charge-transfer adducts. More information can be found in the Research Article by Christian Müller and co-workers.
PubMed: 36892186
DOI: 10.1002/cplu.202300088 -
Journal, Genetic Engineering &... Feb 2023Superoxide dismutase is an important antioxidative stress enzyme which is found in honeybee venom and has a wide pharmaceutical and medical applications.
BACKGROUND
Superoxide dismutase is an important antioxidative stress enzyme which is found in honeybee venom and has a wide pharmaceutical and medical applications.
RESULTS
We reported the purification and characterization of venom SOD from Egyptian honeybee Apis mellifera lamarckii and termed BVSOD. It was purified to homogeneity from the Egyptian honeybee venom. The purification procedures included crude extraction, DEAE-cellulose anion exchange column chromatography, and Sephacryl S-300 gel filtration column chromatography. The purified BVSOD is found to be homogeneous as investigated by native PAGE. It exhibited homodimeric structure with a molecular weight of native form of 32 kDa and subunits of 16.0 kDa. It displayed the maximum activity at pH 7.4. CuCl, ZnCl, and MgCl and elevated the activity of BVSOD, while CoCl, FeCl, and NiCl inhibited BVSOD activity. Potassium cyanide and hydrogen peroxide were most potent inhibitors for BVSOD activity suggesting that it is a Cu/Zn-SOD type.
CONCLUSIONS
The purified BVSOD is found to have antimicrobial and antitumor activities which can be used for various medical and clinical applications.
PubMed: 36807019
DOI: 10.1186/s43141-023-00470-4 -
Environmental Science and Pollution... Mar 2023Endophytic bacteria inhabit plant tissues such as roots, stems, leaves, fruits, and seeds and can multiply inside plant tissue without damaging them. This study involves...
Endophytic bacteria inhabit plant tissues such as roots, stems, leaves, fruits, and seeds and can multiply inside plant tissue without damaging them. This study involves the isolation, characterization, metabolic profiling, and effect of endophytic bacteria isolated from the roots of Scots pine (Pinus sylvestris), on the growth of sunflower. In the current study, fifteen isolates of endophytic bacteria were obtained from the roots of Scots pine, and their molecular characterization was performed using 16 s rRNA ribotyping. The molecular characterization revealed that the strains belonged to Bacillus spp., Pseudomonas spp., Micrococcus sp., Serratia sp., Enterobacter sp., Pantoea sp., Staphylococcus sp., and Microbacterium sp. Among the isolated strains, 9 strains showed positive results for ammonium production, 12 strains for calcium solubilization, 11 strains for magnesium solubilization, 5 strains for zinc solubilization, 12 strains for phosphate solubilization, 8 strains for potassium solubilization, 10 strains for indole acetic acid (IAA) production, 9 strains for siderophore, and 6 strains for hydrogen cyanide (HCN) production. The greenhouse experiment results demonstrated that all isolated endophytic bacteria improved the shoot length, dry weight, and chlorophyll content of sunflower, whereas a significant increase was observed by PS-3 (Bacillus cereus), PS-6 (Serratia marcescens), and PS-8 (Pseudomonas putida). Besides, the concentration of nitrogen, phosphorus, and potassium were also measured in sunflower shoots, and results asserted that bacterial inoculation increased the bioavailability of these essential nutrients to plants compared to uninoculated control. Thus, these endophytic bacteria could be used as an encouraging option to improve plant growth and performance.
Topics: Helianthus; Pinus sylvestris; Endophytes; Bacteria; Asteraceae; Metabolome; Plant Roots
PubMed: 36607575
DOI: 10.1007/s11356-022-25118-7 -
Environmental Pollution (Barking, Essex... Feb 2023Cyanide, which remains the preferred chemical used in the gold extraction process, has the potential to be disposed of on goldmine tailings. South Africa has nine...
Cyanide, which remains the preferred chemical used in the gold extraction process, has the potential to be disposed of on goldmine tailings. South Africa has nine goldfields, producing approximately a third of the world's gold to date. The cyanide interacts with metals in the tailings environment, where Prussian blue [Formula: see text] and Turnbull's blue [Formula: see text] are among these. In previous studies, Prussian blue or Turnbull's blue have been found as a blue substance in tailings material. PHREEQC modelling software was used adding the mineralogical data from 16 tailings samples from the Free State goldfield. The results revealed that Prussian blue prefers to precipitate in an oxic environment and Turnbull's blue prefers an anoxic environment. It was also determined that their precipitation is affected by the availability of iron in solution. As soon as all of the iron is consumed in solution, all excess cyanide produces HCN, which is a free cyanide which volatilizes. Contrarily, Prussian and Turnbull's blue are CN compounds, only dissociating in extremely low pH condition in the absence of photolysis. Ultimately, these iron-cyanide compounds are able to immobilize cyanide, preventing seepage into environments such as the ground water. This along with an anoxic environment such as mine void, keeping the pH high, may be a possible solution for cyanide remediation.
Topics: Humans; Cyanides; Gold; Iron Compounds; Hypoxia; Iron
PubMed: 36503011
DOI: 10.1016/j.envpol.2022.120825