Alkylation Research Articles

ROS‐Activatable Prodrug of Doxazolidine as Novel Cancer Therapy Paradigm

AbstractOvercoming severe side effects from anticancer agents without decreasing their effects on tumor growth is a major challenge. A prodrug technology is reported using agents that are spatiotemporally activated primarily in tumors while the extratumoral toxicity to healthy cells is minimized. A ROS‐activatable prodrug of a strong anticancer agent, doxazolidine (doxaz), is developed. Doxaz is a DNA alkylating agent with a half‐life of 3 min and significantly higher cytotoxicity than the clinically used parental compound doxorubicin (dox). Importantly, doxaz is not affected by p‐glycoprotein expression since it irreversibly alkylates DNA while dox inhibits the topoisomerase II DNA complex. As drug activators, reactive oxygen species (ROS) are already produced inside cancer cells in higher abundance than in normal cells but additionally generated by external stimuli such as radionuclides (via radiolysis of water) and/or ROS‐inducing drugs. We synthesized the prodrug, Doxaz‐BA, and evaluated its efficacy in vitro in cell cultures and then in vivo in xenograft mouse models. Doxaz‐BA is effective in a broad range of cancer cells since most cancer cells produce higher levels of ROS. Combining with clinically relevant radiotracers such as 18F‐FDG or other tumor‐tropic agents / ROS inducing drugs results in a tumor‐specific and enhanced localized therapy paradigm.

6715 Short Adult Height in Childhood Cancer Survivors: Prevalence, Risk Factors, and Genetic Contribution

Abstract Disclosure: T. Yoshida: None. J. Baedke: None. F. Wang: None. W. Moon: None. Y. Sapkota: None. J. Miguel Martínez: None. T.E. Merchant: None. C.L. Wilson: None. K.K. Ness: None. M.M. Hudson: None. Y. Yasui: None. A. Delaney: None. Background: Survivors of childhood cancer are at elevated risk for short adult height (SAH) due to cancer and/or its treatment. In the general population, height is a highly polygenic trait; heritability is estimated to be 70-80%. However, the contribution of genetic factors to SAH among childhood cancer survivors is unknown. In addition, the contribution of chemotherapy agents to risk of SAH among survivors has not been established. We assessed: 1) prevalence of SAH; 2) contribution of genetic factors; and 3) impact of cancer therapy including chemotherapy, on SAH in a large cohort of childhood cancer survivors. Methods: Participants included 4461 childhood cancer survivors aged ≥18 years (female 47.5%, mean age 33.2 years old) with measured height information. SAH was defined as height <3rd percentile for age and sex based on the Centers for Disease Control growth charts. Cancer and treatment history were extracted from medical records. We calculated multi-ancestry height polygenic score (PGS) using the latest methodology developed from 5.4 million individuals of diverse ancestries with more than 1 million variants, where lower score associates with shorter height. With a random sample of 75% of survivors, we fit a multivariable logistic regression model for SAH with the PGS, chemotherapy exposures/doses, corticosteroid exposures/doses, and established risk factors for SAH (e.g., age at cancer diagnosis, radiotherapy exposure) as covariates (main model). The remaining 25% of survivors served for validation of the main model and for the calculation of the population attributable fractions (PAF) of the PGS and cancer treatments. Results: The prevalence of SAH was 8.9% among all survivors (9.3% in males; 8.5% in females) and differed widely by primary cancer diagnosis. SAH was associated with lower PGS [odds ratio (OR) 0.47, 95% confidence interval (CI) 0.40-0.55 for a one standard deviation increase], alkylating agent exposure of >12000 mg/m2 (OR 2.19, 95% CI 1.41-3.38, vs. non-exposure), and spinal radiotherapy (OR 3.65, 95% CI 2.23-6.00, vs. non-exposure). Radiotherapy exposure to the hypothalamic-pituitary region and younger age at cancer diagnosis was also associated with SAH in a dose-response manner. The area under the ROC curve of the main model in the validation dataset was 0.80 (95% CI 0.74-0.87), suggesting good predictive ability for SAH by the model. The PAF of SAH calculated from the multiplicative logistic regression model of SAH was 85.7% for cancer treatments and 30.2% and 60.2% for having PGS below the median and the 90th percentile, respectively. Conclusions: Cancer treatments are the primary contributor to SAH risk among survivors with a PAF of 85.7%. Exposure to high-dose alkylating agents contributes to this along with radiotherapy. Inherited genetic factors also affect SAH among survivors but to a much lesser degree than cancer treatments. Presentation: 6/3/2024

N 2-Alkyl-dG lesions elicit R-loop accumulation in the genome.

Humans are exposed to DNA alkylating agents through endogenous metabolism, environmental exposure and cancer chemotherapy. The resulting alkylated DNA adducts may elicit genome instability by perturbing DNA replication and transcription. R-loops regulate various cellular processes, including transcription, DNA repair, and telomere maintenance. However, unscheduled R-loops are also recognized as potential sources of DNA damage and genome instability. In this study, by employing fluorescence microscopy and R-loop sequencing approaches, we uncovered, for the first time, that minor-groove N2-alkyl-dG lesions elicit elevated R-loop accumulation in chromatin and in plasmid DNA in cells. We also demonstrated that the N2-alkyl-dG-induced R-loops impede transcription elongation and compromise genome integrity. Moreover, genetic depletion of DDX23, a R-loop helicase, renders cells more sensitive toward benzo[a]pyrene diolepoxide, a carcinogen that induces mainly the minor-groove N2-dG adduct. Together, our work unveiled that unrepaired minor-groove N2-alkyl-dG lesions may perturb genome integrity through augmenting R-loop levels in chromatin. Our findings suggest a potential therapeutic strategy involving the combination of R-loop helicase inhibitors with DNA alkylating drugs.

Magnesium 4, 5, and 6 coordinate complexes with ligands bound via sp or sp2 hybridized atoms

As a metallic element of high natural abundance, magnesium finds a wide range of uses in both stoichiometric and more recently catalytic applications. This often takes advantage of the basic or nucleophilic properties of its compounds or their ability to co-complex with other organometallic compounds. However, the homoleptic chemistry of Mg(II) is heavily skewed towards alkyl and aryl ligands bound via sp2 and sp3 hybridized atoms. Here, we report our combined NMR spectroscopic and X-ray crystallographic study into much rarer alternative THF solvates of homoleptic magnesium complexes using ligands which bind via sp (alkynyl) and sp2 (imido) atoms. Specifically, we exploit the high acidity of terminal alkynes and diphenylacetonitrile to prepare tetra-solvated distorted octahedral complexes Mg(CCC6H4R-p)2(THF)4 (R = Me, CF3) and Mg(NCCPh2)2(THF)4 starting from the commercial alkyl reagent MgBu2. Adopting a similar deprotonative strategy using benzophenoneimine Ph2CNH affords the heteroleptic trinuclear complex Mg3(NCPh2)4nBu2(THF)2 with distorted tetrahedral Mg centres. Related imidomagnesium halide complexes can be accessed either by deprotonation of the imine with a Grignard reagent, or nucleophilic addition of a Grignard reagent to a nitrile, but these unusual five-coordinate complexes are unresponsive to a 1,4-dioxane induced Schlenk equilibrium shift. Employing a higher reflux temperature switching from a THF to a toluene medium permits access to the THF solvate of a homoleptic imido complex which also possesses a trinuclear constitution in Mg3(NCPh2)6(THF)2.

Trabectedin promotes oncolytic virus antitumor efficacy, viral gene expression, and immune effector function in models of bone sarcoma

We previously reported that the DNA alkylator and transcriptional-blocking chemotherapeutic agent trabectedin enhances oncolytic herpes simplex viroimmunotherapy in human sarcoma xenograft models, though the mechanism remained to be elucidated. Here we report trabectedin disrupts the intrinsic cellular anti-viral response which increases viral transcript presence in the human tumor cells. We also extended our synergy findings to syngeneic murine sarcoma models, which are poorly susceptible to virus infection. In the absence of robust virus replication, we found trabectedin enhanced viroimmunotherapy efficacy by reducing infiltrating immunosuppressive CD4 T and myeloid cells and stimulating granzyme expression in infiltrating T and NK cells to cause immune-mediated tumor regressions. Thus, trabectedin enhances both the direct virus-mediated killing of tumor cells and the viral-induced activation of cytotoxic effector lymphocytes to cause tumor regressions across models. Our data provide a strong rationale for clinical translation as both mechanisms should be simultaneously active in human patients.

Ultrafine Network-Like Monolayer Structures of Amphiphilic Hyperbranched Copolymers Revealed by the Relative Aggregation Number Method.

The aggregation behavior of two amphiphilic hyperbranched copolymers of poly[oligo(ethylene glycol) methacrylate-co-lauryl methacrylate] (H-[P(OEGMA-co-LMA)]) at the air/water interface was investigated by using the Langmuir film balance technique and atomic force microscopy (AFM). At the air/water interface, H-[P(OEGMA-co-LMA)] copolymers spontaneously form the ultrafine network-like monolayer structures of micelles; each micelle consists of a tiny hydrophobic core of one or two carbon backbones and lauryl side groups and a short hydrophilic shell of oligo(ethylene glycol) (OEG) side groups, and the micellar cores are connected by the branching agent ethylene glycol dimethacrylate (EGDMA). These ultrafine micellar structures are successfully revealed by our relative aggregation number method presented in this work, which is based on our previous relative mass method and methylene number method. The surface pressure-molecular area isotherms of POEGMA29%-PLMA71% (weight percent) and POEGMA69%-PLMA31% are condensed and expanded, respectively, because the density/number of OEG side groups in the former shells is smaller than that in the latter case. Upon monolayer compression, the isotherms of the former are classified into regions I-IV, whereas those of the latter are classified into regions II and III based on their different variation trends of surface pressure. Subphase pH has little influence on the isotherms of the two copolymers because the stretching degrees of hydrophilic OEG side groups in the shells are probably limited by the connected cores, which is different from the large effects in our previous block copolymers containing POEGMA or poly[oligo(ethylene glycol) acrylate] blocks. Under neutral and alkaline conditions, in region III, the mean molecular area (mmA) values of the isotherms of the two copolymers at 20 °C are smaller than those at 10 °C due to the collapse of the OEG side groups above 15 °C. Furthermore, the isotherms of POEGMA69%-PLMA31% move to larger mmA values at 30 °C due to the increased thermal mobility and stretching degrees of more OEG side groups.

Identification of a novel DNA oxidative damage repair pathway, requiring the ubiquitination of the histone variant macroH2A1.1

BackgroundThe histone variant macroH2A (mH2A), the most deviant variant, is about threefold larger than the conventional histone H2A and consists of a histone H2A-like domain fused to a large Non-Histone Region responsible for recruiting PARP-1 to chromatin. The available data suggest that the histone variant mH2A participates in the regulation of transcription, maintenance of heterochromatin, NAD+ metabolism, and double-strand DNA repair.ResultsHere, we describe a novel function of mH2A, namely its implication in DNA oxidative damage repair through PARP-1. The depletion of mH2A affected both repair and cell survival after the induction of oxidative lesions in DNA. PARP-1 formed a specific complex with mH2A nucleosomes in vivo. The mH2A nucleosome-associated PARP-1 is inactive. Upon oxidative damage, mH2A is ubiquitinated, PARP-1 is released from the mH2A nucleosomal complex, and is activated. The in vivo-induced ubiquitination of mH2A, in the absence of any oxidative damage, was sufficient for the release of PARP-1. However, no release of PARP-1 was observed upon treatment of the cells with either the DNA alkylating agent MMS or doxorubicin.ConclusionsOur data identify a novel pathway for the repair of DNA oxidative lesions, requiring the ubiquitination of mH2A for the release of PARP-1 from chromatin and its activation.

MnFe2O4 Nanoparticles‐Catalyzed C3‐Alkylation of Indoles with Benzyl Alcohols under Solvent‐Free Conditions

AbstractHerein, we present an efficient, one‐pot reaction for accessing 3‐benzylated indoles via the coupling of benzyl alcohols with indoles under heterogeneous catalysis by manganese ferrite (MnFe2O4) nanoparticles. Notably, this reaction, for the first time, employs MnFe2O4 nanoparticles prepared using a simple grinding method. The high compatibility of MnFe2O4 nanoparticles enables a broad substrate scope and high regioselectivity. Moreover, this approach offers several attractive highlights including the use of a recyclable oxide catalyst and green and cost‐effective alkylating reagents under solvent‐free conditions.

Visible Light-Mediated Late-Stage Thioetherification of Mercaptopurine Derivatives.

We disclose herein a novel and general radical approach to alkylthiopurines, encompassing 4 types of thiopurines, as well as their corresponding ribosides. This strategy is achieved through visible light-mediated late-stage functionalization of the sulfur atoms of mercaptopurines. The in situ-generated disulfide was proposed as the pivotal neutral intermediate for this transformation. We present herein a novel photo-mediated homolytic C-S bond formation for the preparation of alkylthiopurines and alkylthiopurine nucleosides. Despite the presence of reactive sites for the Minisci reaction, chemoselective S-alkylation remained the predominant pathway. This method allows for the late-stage introduction of a broad spectrum of alkyl groups onto the sulfur atom of unprotective mercaptopurine derivatives, encompassing 2-, 6-, and 8-mercaptopurine rings. Organoborons serve as efficient and eco-friendly alkylating reagents, providing advantages in terms of readily availability, stability, and reduced toxicity. Further derivatization of the thioetherified nucleosides, together with anti-tumor assays, led to the discovery of potent anti-tumor agents with an IC50 value reaching 6.1 μM (Comp. 31 for Jurkat).

Hydrodeuteroalkylation of Unactivated Olefins Using Thianthrenium Salts

AbstractIsotopically labeled alkanes play a crucial role in organic and pharmaceutical chemistry. While some deuterated methylating agents are readily available, the limited accessibility of other deuteroalkyl reagents has hindered the synthesis of corresponding products. In this study, we introduce a nickel‐catalyzed system that facilitates the synthesis of various deuterium‐labeled alkanes through the hydrodeuteroalkylation of d2‐labeled alkyl TT salts with unactivated alkenes. Diverging from traditional deuterated alkyl reagents, alkyl thianthrenium (TT) salts can effectively and selectively introduce deuterium at α position of alkyl chains using D2O as the deuterium source via a single‐step pH‐dependent hydrogen isotope exchange (HIE). Our method allows for high deuterium incorporation, and offers precise control over the site of deuterium insertion within an alkyl chain. This technique proves to be invaluable for the synthesis of various deuterium‐labeled compounds, especially those of pharmaceutical relevance.

Hydrodeuteroalkylation of Unactivated Olefins Using Thianthrenium Salts.

Isotopically labeled alkanes play a crucial role in organic and pharmaceutical chemistry. While some deuterated methylating agents are readily available, the limited accessibility of other deuteroalkyl reagents has hindered the synthesis of corresponding products. In this study, we introduce a nickel-catalyzed system that facilitates the synthesis of various deuterium-labeled alkanes through the hydrodeuteroalkylation of d2-labeled alkyl TT salts with unactivated alkenes. Diverging from traditional deuterated alkyl reagents, alkyl thianthrenium (TT) salts can effectively and selectively introduce deuterium at α position of alkyl chains using D2O as the deuterium source via a single-step pH-dependent hydrogen isotope exchange (HIE). Our method allows for high deuterium incorporation, and offers precise control over the site of deuterium insertion within an alkyl chain. This technique proves to be invaluable for the synthesis of various deuterium-labeled compounds, especially those of pharmaceutical relevance.

A new method of development and validation of Methanesulfonic acid ester (Methyl, Ethyl) impurity content in dabigatran etexilate mesylate by GC MS

We attempted to establish a method for estimating methane sulfonic acid methyl or ethyl ester in the dabigatran etexilate Mesylate in bulk and pharmaceutical dosage form. Dabigatran is an anticoagulant used in deep vein thrombosis and lung thrombosis. Methane sulfonic acid and ethyl sulfonic acid are DNA ethylating agents and genotoxic. These compounds can be estimated using the GC MS method using Helium as a carrier gas, and the compounds are estimated to be at 79 and 400 masses. The 60% methanol is used as diluent and blank. The method is validated as per the procedures of ICH, and all the validation parameters are within the acceptable limit of the impurities guidelines, as stated in the Q4 section. The different batches were analyzed using the same technique, and no impurities were found; hence, the batches were passed.

Oxide-Encapsulated Silver Electrocatalysts for Selective and Stable Syngas Production from Reactive Carbon Capture Solutions.

Electrolysis of bicarbonate-containing CO2 capture solutions is a promising approach towards achieving low-cost carbon-neutral chemicals production. However, the parasitic bicarbonate-mediated hydrogen evolution reaction (HER) and electrode instability in the presence of trace impurities remain major obstacles to overcome. This work demonstrates that the combined use of titanium dioxide (TiO2) overlayers with the chelating agent ethylene diamine tetra-acetic acid (EDTA) significantly enhances the selectivity and stability of Ag-based electrocatalysts for bicarbonate electrolysis. The amorphous TiO2 overlayers suppress the HER by over 50 % at potentials more negative than -0.7 V vs. RHE, increasing the CO faradaic efficiency (FE) by 33 % (relative). In situ surface-enhanced Raman spectroscopy (SERS) measurements reveal the absence of near-surface bicarbonate species and an abundance of CO2 reduction intermediates at the Ag|TiO2 buried interface, suggesting that the overlayers suppress HER by blocking bicarbonate ions from reaching the buried active sites. In accelerated degradation tests with 5 ppm of Fe(III) impurity, the addition of EDTA allows stable CO production with >47 % FE, while the electrodes rapidly deactivate in the absence of EDTA. This work highlights the use of TiO2 overlayers for enhancing the CO : H2 ratio while simultaneously protecting electrocatalysts from impurities likely to be present in "open" carbon capture systems.

Oxide‐Encapsulated Silver Electrocatalysts for Selective and Stable Syngas Production from Reactive Carbon Capture Solutions

AbstractElectrolysis of bicarbonate‐containing CO2 capture solutions is a promising approach towards achieving low‐cost carbon‐neutral chemicals production. However, the parasitic bicarbonate‐mediated hydrogen evolution reaction (HER) and electrode instability in the presence of trace impurities remain major obstacles to overcome. This work demonstrates that the combined use of titanium dioxide (TiO2) overlayers with the chelating agent ethylene diamine tetra‐acetic acid (EDTA) significantly enhances the selectivity and stability of Ag‐based electrocatalysts for bicarbonate electrolysis. The amorphous TiO2 overlayers suppress the HER by over 50 % at potentials more negative than −0.7 V vs. RHE, increasing the CO faradaic efficiency (FE) by 33 % (relative). In situ surface‐enhanced Raman spectroscopy (SERS) measurements reveal the absence of near‐surface bicarbonate species and an abundance of CO2 reduction intermediates at the Ag|TiO2 buried interface, suggesting that the overlayers suppress HER by blocking bicarbonate ions from reaching the buried active sites. In accelerated degradation tests with 5 ppm of Fe(III) impurity, the addition of EDTA allows stable CO production with >47 % FE, while the electrodes rapidly deactivate in the absence of EDTA. This work highlights the use of TiO2 overlayers for enhancing the CO : H2 ratio while simultaneously protecting electrocatalysts from impurities likely to be present in “open” carbon capture systems.

P-521 Inter-individual variation in gonadotoxicity in female childhood cancer survivors – a genome-wide association study: results from the PanCareLIFE study

Abstract Study question To identify new variants associated with alkylating agent (AA) induced gonadotoxicity among adult female childhood cancer survivors (CCS) using a genome-wide association study approach (GWAS). Summary answer Upon meta-analysis of two independent cohorts, the variant rs78861946 was associated with lower AMH levels in CCS, but not separately in the smaller replication cohort. What is known already Female childhood cancer survivors are at risk of therapy-related gonadal impairment. Alkylating agents are well-established risk factors, and the inter-individual variability in gonadotoxicity may be explained by genetic polymorphisms. Study design, size, duration A genome-wide association study (GWAS) approach was used to discover new variants associated with AA-induced gonadotoxicity among adult female CCS. The discovery cohort included adult female CCS from the pan-European PanCareLIFE cohort (n = 743; median age: 25.8 years), excluding those who received bilateral ovarian irradiation, bilateral oophorectomy, CNS, total body irradiation, or stem cell transplantation. Results were replicated in the USA-based St. Jude Lifetime Cohort (n = 391; median age: 31.3 years) and combined in a meta-analysis. Participants/materials, setting, methods Anti-Müllerian hormone (AMH) levels served as a proxy for ovarian function in both the discovery and replication cohort. A GWAS was performed using a linear regression model adjusted for cyclophosphamide equivalent dose of alkylating agents, age at diagnosis, and age at study. Main results and the role of chance Three genome-wide significant (<5.0x10E-8 ) and 16 genome-wide suggestive (<5.0x10E-6 ) loci were associated with log-transformed AMH levels, adjusted for cyclophosphamide equivalent dose of alkylating agents, age at diagnosis, and age at study in the PanCareLIFE cohort. Based on effect allele frequency (EAF) (>0.01 if not genome-wide significant), p-value (<5.0 × 10E−6 ), and biological relevance, 15 SNPs were selected for replication in the independent replication cohort of the St. Jude Lifetime Cohort. None of the SNPs were statistically significantly associated with AMH levels in this smaller cohort. A meta-analysis indicated thatrs78861946 was associated at borderline genome-wide statistical significance (reference/effect allele: C/T;EAF: 0.04, Beta (SE): −0.484 (0.091), p-value= 9.39 × 10E−8). While the sample size of both the discovery and replication cohorts are large for CCS cohorts, they are very small compared to GWASs in the general population. The limited power is likely one of the reasons the identified SNPs were not statistically significant in our replication cohort of SJLIFE. Limitations, reasons for caution While AMH is a valuable surrogate marker for ovarian reserve, it remains a proxy for ovarian reserve and low AMH levels may still coincide with fertility potential and pregnancy. Wider implications of the findings Identification of risk-contributing variants such as rs78861946 may prove useful to better identify patients who are specifically susceptible for alkylating agent-induced gonadal toxicity. Future polygenic risk scores may aid individualized counselling regarding the treatment-related risk of gonadotoxicity and fertility preservation options for female childhood cancer survivors. Trial registration number not applicable

Combination Therapy with Immune Checkpoint Inhibitors and Histone Deacetylase Inhibitors or Alkylating Agents.

Immune checkpoint inhibitors (CPIs) have been widely adopted in a number of early and advanced malignancies. Histone deacetylase inhibitors (HDACis) and alkylating agents (AAs) have been suggested to potentiate the actions of CPIs on tumor cells. We conducted a comprehensive literature review to explore the potential synergistic activity between CPIs, AAs, and HDACis. Clinical and non-clinical studies describing outcomes in patients with cancer receiving CPIs and either concomitant or sequential (pre- or post-CPI) AAs or HDACis were identified in PubMed using pre-defined search strings. Manual searches of key oncology congresses were similarly performed. All relevant articles and abstracts were manually screened for relevance, classified according to the specific anticancer agents used (CPIs, AAs, or HDACis), tumor entity, and whether treatment was concomitant or sequential. Overall, 227 unique clinical studies across a range of tumor types, both solid tumors and hematological malignancies, were identified. One hundred and fifty-nine publications on Phase I and II clinical studies together with 41 publications on Phase III studies were examined. The most commonly investigated tumor types were melanoma, triple-negative breast cancer, non-small cell lung cancer, and Hodgkin lymphoma. The randomized clinical studies identified, all of which reported on the combination of a CPI with an AA, demonstrated superior outcomes in the combination arm compared with CPI or AA monotherapy. Similarly, combination therapy with CPIs and HDACis demonstrated promising activity. Sequential or concomitant administration of a CPI with an AA or an HDACi may improve outcomes for patients with a range of tumor types. There is a rationale to support further investigation into the potential for synergy between CPIs, alkylating agents and/or HDACis in both the non-clinical and clinical settings.

Continuous alkylation of 1,3,5-trihydroxy-2,4,6-trinitrobenzene in microreactor: Process intensification and reaction kinetics

1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is an essential insensitive energetic material. The alkylation of 1,3,5-trihydroxy-2,4,6-trinitrobenzene (Trinitrophloroglucinol, TNPG), which yields 1,3,5-triethoxy-2,4,6-trinitrobenzene (TETNB), is a pivotal step for the synthesis of TATB. The conventional synthetic process has suffered from long reaction time (∼165 min), intricate procedures, and intensive evaporation of a large number of volatile by-products, which increases the risk of spill and eruption of the reaction system, and necessitates in situ continuous gas–liquid separation. A new process for continuous alkylation in microreactors was proposed in this study. Firstly, a parametric investigation in the batch reactor was performed to explore the effects of various process parameters on the yields, resulting in the optimal experimental conditions, i.e., no reflux condensation, triethyl orthoformate (TEOF) as alkylation reagent, molar ratio of 12, reaction temperature of 120 °C and reaction time of 40 min. Subsequent continuous synthesis in microreactors was conducted, which realized the convenient process operation and no need of gas–liquid separation, leading to substantial improvement in the reaction efficiency and safety. Remarkably, within a packed microreactor, under the reaction temperature of 130 °C and residence time of 3 min, 99.24 % in the yield of TETNB was achieved. Comparing with conventional batch reactors, the required reaction time was reduced to approximately 1/50. Taking the advantages of precise control of temperature and reaction time in the microreactors, the kinetics of alkylation reaction were determined. This innovative approach of continuous synthesis can provide an efficient and alternative route for the synthesis of TATB, as well as other energetic materials and similar processes.

The Flavoring Agent Ethyl Vanillin Induces Cellular Stress Responses in HK-2 Cells.

Flavored e-cigarettes are a popular alternative to cigarette smoking; unfortunately, the extrapulmonary effects are not well-characterized. Human proximal tubule cells were cultured for 24 or 48 h with 0-1000 µM ethyl vanillin (ETH VAN) and cytotoxicity evaluated. Mitochondrial health was significantly diminished following 48 h of exposure, accompanied by significantly decreased spare capacity, coupling efficiency, and ATP synthase expression. ETH VAN at 24 h inhibited glycolysis. The endoplasmic reticulum (ER) stress marker C/EBP homologous protein (CHOP) was increased at 100 μM relative to 500-1000 μM. The downstream proapoptotic marker cleaved caspase-3 subsequently showed a decreasing trend in expression after 48 h of exposure. The autophagy biomarkers microtubule-associated proteins 1A/1B light chain 3 (LC3B-I and LC3B-II) were measured by Western blot. LC3B-II levels and the LC3B-II/LC3B-I ratio increased at 24 h, which suggested activation of autophagy. In contrast, by 48 h, the autophagy biomarker LC3B-II decreased, resulting in no change in the LC3B-II/LC3B-I ratio. Mitophagy biomarker PTEN-induced putative kinase 1 (PINK1) expression decreased after 48 h of exposure. The downstream marker Parkin was not significantly changed after 24 or 48 h. These findings indicate that the flavoring ETH VAN can induce energy pathway dysfunction and cellular stress responses in a renal model.

Synthesis and characterization of alkali metal iminophosphoranomethanide complexes

Herein we report the synthesis of three sets of alkali metal complexes with the iminophosphoranomethanide ligands {CH(SiMe3)P(Ph)2NSiMe3}− (TMSNPC-H) and {CH(SiMe2tBu)P(Ph)2NSiMe3}− (TBDMSNPC-H), the latter of which is first reported here. The compounds of general formula [M(RNPC-H)] (3-M and 4-M; M = Li, Na, K) were obtained via a protonolysis reaction between an alkyl reagent (n-butyllithium, benzylsodium, or benzylpotassium) and the proligand. All resulting compounds were characterized by multinuclear NMR, IR spectroscopy, elemental analysis and single crystal X-ray diffraction. We also attempted to prepare the separated ion pairs of [M(TMSNPC-H)] with the matched crown ethers, and obtained the ‘ate’ complexes [Li(12-crown-4)2]+[Li(TMSNPC-H)2]− (5-Li) and [Na(15-crown-5)2]+[Na(TMSNPC-H)2]− (5-Na), the coordination polymer [{K(18-crown-6)2}{K(TMSNPC-H)(18-crown-6)}(TMSNPC-H)]∞ (6) and separate ion pair complex [K(15-crown-5)2]+[TMSNPC-H]− (7). 5-Li is an unusual lithium-lithiate crown ether species, whilst 5-Na represents the first example of a sodium-sodiate crown-ether complex.

Pre-mating exposure with hesperidin protects N-ethyl-N-nitrosourea-induced neurotoxicity and congenital abnormalities in next generation of mice as a model of glioma.

Chemical carcinogen-induced oxidative stress has a key role in cell signaling linked to the development of cancer. Oxidative stress leads to oxidative damage to cellular membranes, proteins, chromosomes and genetic material. It is thought that compounds like hesperidin with high antioxidant and anticancer potential can reduce development of cancer induced by chemical carcinogens via neutralizing their oxidative damages. We investigated protective effect of hesperidin against N-Ethyl-N-Nitrosourea (ENU)-induced neurotoxicity, congenital abnormalities and possible brain cancer after exposure of mice during pregnancy as model of glioma. The mice were divided to four groups; control (normal saline), ENU (40mg/kg daily for three consecutive days from the 17th to the 19th of pregnancy), hesperidin (pretreated with 25mg/kg for 30 consecutive days, before mating) + ENU and hesperidin alone. Developmental toxicity parameters (the number of pregnant mice, stillbirths, abortion, live and dead offspring), behavioral tests (novel object recognition, open field and elevated plus maze) were performed. Moreover, the activity of butrylcholinesterase and acetylcholinesterase enzymes, oxidative markers and histopathological abnormalities were detected in brain tissue. Our data showed that conversely, the pretreatment of hesperidin reduces various degrees of developmental toxicity, neurobehavioral dysfunction, neurotoxicity, oxidative stress and histopathological abnormalities induced by ENU as a neurotoxic and carcinogenic agent in the next generation. In conclusion, pre-mating exposure with hesperidin may open new avenues for prevention of primary brain cancer in next generation and could be valuable for enhancing the antioxidant defense and minimizing the developmental and neurotoxicity of DNA alkylating agents.