Alkylene Oxide Research Articles

Novel diorganotin(IV) carboxylates based on 2-benzoylbenzoic acid: Synthesis, characterization, molecular structures and luminescent activities

Two novel diorganotin(IV) carboxylates: Ph2SnL2 1 and Cy2SnL2 2 (HL = 2-benzoylbenzoic acid), were assembled by dialkyltin oxide (alkyl = phenyl or cyclohexyl) and HL with 1:2 molar ratio. The synthesized complexes have been structurally characterized by elemental analysis, IR, 1H, 13C, 119Sn NMR spectroscopy and X-ray crystallography diffraction analyses. Both 1 and 2 are mono-nuclear dialkyltin carboxylates. The carboxylate groups of HL in 1 and 2 adopt bidentate mode to coordinate with the central Sn atom. 1D, 2D and 3D supramolecular structures formed by intermolecular hydrogen bonds, C-H···π and π···π interactions are discussed in detail. Furthermore, the preliminary luminescent properties of 1 and 2 have been studied.

Alkylene oxides

Alkylene oxides

Cross-linked chitosan aerogel modified with Pd(II)/phthalocyanine: Synthesis, characterization, and catalytic application

Palladium(II) phthalocyanine (PdPc) tetrasulfonate was chemically bonded to an amine moiety of chitosan aerogel. The reaction was promoted by the transformation of sulfonic acid groups of PdPc to sulfonyl chloride, which is highly active for amination. The porous composite showed good catalytic activity in the oxidation reaction of some alkylarenes, aliphatic and benzylic alcohols, and cyclohexanol. High conversions and excellent selectivities were obtained for the solvent-free reactions under aerobic conditions at 80 °C during 24 h. While many oxidation reactions have been reported catalysed with palladium phthalocyanine, this is the first reported oxidation of alkylarenes via this catalyst. The organometallic compound is applicable as a heterogeneous catalyst having high chemical stability with recyclability up to six times.

Asymmetric synthesis of ABC tricyclic systems in Daphniphyllum alkaloid

Efficient synthetic routs for the direct and rapid construction of [5-6-6] ABC tricyclic systems of daphmanidin A-type and calyciphylline A-type alkaloids have been successfully developed. For the daphmanidin A-type, the synthesis of [5-6-6] tricyclic framework utilize a HCl-mediated intramolecular Aldol reaction to construct the bicyclo[2.2.2]octane core and a thermal condensation to afford the ABC ring system. In addition, for the calyciphylline A-type, an improved synthesis of ABC [5-6-6] tricyclic system was developed, featuring an introduction of methyl ester group at C2 before the Pd-catalyzed intramolecular oxidative alkylation to construct the desired bowl-shape tricyclic core with stereochemical control.

Abstract LB-205: A lipoplex-based mRNA nanovaccine for cancer immunotherapy

Abstract Intracellular delivery of messenger RNA (mRNA)-based cancer vaccines have shown great potential to activate antitumor immune response for cancer prevention and therapy. In vivo delivery efficiency of mRNA has been greatly improved by various nucleotide chemical modifications and nanovector formulations, but the efficacy of mRNA vaccine remains unsatisfied. Here, we report a lipoplex-based mRNA nanovaccine that can markedly improve mRNA delivery in antigen presenting cells, activate T cell response, and induce robust antitumor immunity. The nanovaccine formulation contains three components: cationic polymer/lipid(poly(amidoamine)/alkylene oxide), DSPE-PEG2000, and epitope-encoding mRNA. With appropriate ratio, the optimized nanovaccine show effective mRNA delivery in dendritic cells, and strongly active antigen-specific immune response in vitro and in vivo. The mRNA@lipoplex nanovaccine enhanced mRNA uptake by dendritic cells, and significantly increased T cell activation reflected by IL-2 and IFN-γsecretion in an in vitro antigen presentation assay. Besides enhancing cross-presentation, nanoparticle itself can promote the expression of inflammatory cytokines such as IL-12 via stimulating NF-κB signal pathway in dendritic cells. In a tumor prevention setting, mRNA@lipoplex nanovaccine produced strong CD8+ T cell activation and great efficacy in preventing tumor development. Furthermore, treatment of established B16 and B16-OVA melanoma and MC38-OVA colon tumors with nanovaccine containing mRNA encoding cancer-associated antigen resulted in great therapeutic efficacy and prolonged survival. Re-challenge of tumor-free mice with MC38-OVA cells led to complete tumor rejection, suggesting long-term antitumor memory. In conclusion, our work presents a new means to deliver mRNA cancer vaccine, which in principle may be applied for immunotherapy for a wide range of tumor types. Citation Format: Zhang Hongxia, You Xinru, Wang Xiaojuan, Wang Zining, Xu Feifei, Wu Jun, Xia Xiaojun. A lipoplex-based mRNA nanovaccine for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-205.

Abstract 1758: Splicing component ISY1 interacts with APE1 and regulates base excision repair

Abstract Cellular genome is continuously challenged by endogenous and exogenous DNA damaging agents. In the genome, base modifications are the most common form of DNA damage. Base excision DNA repair (BER) is the most important pathway for the removal of oxidized or alkylated DNA. If these base modifications continue to persist, the replisome may stall at DNA lesions, causing the replication fork to collapse, leading to genetic instability. While the main components of the BER pathway are well defined, its regulatory mechanism remains poorly understood. We report here that apurinic/apyrimidinic endonuclease 1 (APE1), a multifunctional protein interacts with the pre-mRNA splicing factor ISY1. However, this interaction is independent of DNA or RNA based upon our pull-down experimental results. ISY1 expression is induced by oxidative or DNA alkylation damage, which would then provide an immediate up-regulation of APE1 activity in vivo and enhanced BER of oxidized bases. This was supported from our results of in vitro reconstituted experiment suggesting that ISY1 can stimulate 5’-3’ endonuclease 1 activity of APE1 in both the short- and long-patch BER pathways and increase its binding to AP site DNA. The interaction between ISY1 and APE1 also establishes a connection between DNA damage repair and pre-mRNA splicing. Based upon these results, we propose that ISY1 is an important regulator of BER and enhances the ability of APE1 to efficiently recognize abasic sites in DNA. Role of ISY1 becomes important in aging tissues where decreased APE1 activity results in the accumulation of oxidative genomic damages. Therefore, ISY1 may work as an anti-aging factor. Induction of ISY1 in malignancies could constitute a mechanism to avoid apoptotic death after treatment with alkylating agents. Citation Format: Aruna Jaiswal, Elizabeth Williamson, Bhavita Patel, Gayathri Srinivasan, Kimi Kong, Carrie Lomelino, Satya Narayan, Robert Hromas. Splicing component ISY1 interacts with APE1 and regulates base excision repair [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1758.

Copper‐Catalyzed Oxidative Alkylation of Vinylic Cβ‐H of Enamides with Cyclic Ethers

AbstractA general strategy for the oxidative alkylation of vinylic Cβ‐H bond of enamides catalyzed by copper to prepare structurally diverse ethers was developed. Under standard reaction conditions, various cyclic and acyclic enamides reacted well with cyclic ethers to afford the corresponding multi‐substituted alkene products in good yields. In addition, the coupling products could be converted into useful amino alcohol derivatives. The coupling reaction was considered to follow a mechanism based on radical pathway.

Selective oxidation of alkylarenes to aromatic acids/ketone in water by using reusable binaphthyl stabilized Pt nanoparticles (Pt-BNP) as catalyst

An efficient methodology for the selective and controlled oxidation of petroleum waste methylarenes/alkylarenes to aromatic carboxylic acids/ketone using easily recoverable and recyclable binaphthyl stabilized Pt nanoparticles (Pt-BNP) as a catalyst has been developed. The greener oxidant aq. tert-butyl hydroperoxide (TBHP) and green solvent water have been utilized in this oxidation reaction. The methodology is well tolerated with different functional groups. The less reactive electron deficient toluenes are also oxidized by Pt-BNP and gave a good yield of corresponding carboxylic acids with a high turnover number (TON) 738-1448. The Pt-BNP catalyst was recovered and reused up to five catalytic cycles. The heterogeneous test suggested that the reaction is catalyzed by heterogeneous Pt-BNP catalysts. Based on control experiments and literature reports, a possible reaction mechanism has been proposed.

Sonochemical fabrication of Pd/TiO2-nanotubes/Ti plate as a green catalyst for oxidation of alkylarenes and benzyl alcohols

A facile and fast strategy has been employed to fabricate Pd nanoparticles supported on TiO2 nanotubes/Ti plate via sonochemical deposition. Microstructure studies showed the homogeneous deposition of Pd nanoparticles on the walls of TiO2 nanotubes/Ti plate. The synthesized plate was applied as a novel catalyst for the oxidation of benzyl alcohol and ethylbenzene derivatives. The results of catalytic experiments demonstrated that the modified plate was an efficient green catalyst for the oxidation of benzyl alcohols to benzoic acid derivatives in H2O. The oxidation of alkylarenes was carried out in EtOH:H2O (1:1) ended up with the formation of the corresponding ketone as the sole product. High yields and excellent selectivities were obtained for the oxidation reactions in green solvents using green oxidant. Superior catalytic activity, easy catalyst recovery, and reusability of the catalyst are some advantages of the modified PdNPs/TiO2 nanotubes/Ti plate, indicating a potential application of the catalyst in the industrial oxidation reactions.

Quantitative Grafting for Structure-Function Establishment: Thermoresponsive Poly(alkylene oxide) Graft Copolymers Based on Hyaluronic Acid and Carboxymethylcellulose.

A series of thermoresponsive graft copolymers, gelling at physiological conditions in aqueous solution and cell growth media, have been synthesized using quantitative coupling between a small set of amino-functionalized poly(alkylene oxide) copolymers (PAO) and the carboxylate of the biologically important polysaccharides (PSa) carboxymethylcellulose and the less reactive hyaluronate. Quantitative grafting enables the establishment of structure-function relationship which is imperative for controlling the properties of in situ gelling hydrogels. The EDC/NHS-mediated reaction was monitored using SEC-MALLS, which revealed that all PAOs were grafted onto the PSa backbone. Aqueous solutions of the graft copolymers were Newtonian fluids at room temperatures and formed reversible physical gels at elevated temperatures which were noncytotoxic toward chondrocytes. The established structure-function relationship was most clearly demonstrated by inspecting the thermogelling strength and the onset of thermogelling in a phase diagram. The onset of the thermogelling function could be controlled by the global PAO concentration, independent of graft ratio.

Rapid Formation of Advanced Scaffolds from Phenols and Anilines

This article is an account of our efforts over the last decade to functionalize phenols and anilines at any position and to use these compounds to generate substituted aromatic systems and advanced unsaturated cyclohexanone moieties, enabling the rapid formation of complex structures. Total syntheses of numerous natural products involving such intermediates were achieved.1 Introduction2 ortho-Functionalization of Phenols and Aniline Derivatives Mediated by Iodanes (III) and Synthesis of Panacene2.1 Cross-Coupling with Aniline Derivatives2.2 Dearomative Cycloaddition of Arenes and Heteroarenes2.3 Total Synthesis of Panacene3 meta-Functionalization of Aniline Derivatives and Synthesis of Erysotramidine3.1 meta-Functionalization of Aniline Derivatives3.2 Total Synthesis of Erysotramidine4 para-Functionalization of Phenols and Applications in Total Synthesis4.1 Bimolecular Approach Mediated by Protecting Groups4.2 ipso-Rearrangement4.3 Oxidative Alkyl Shift4.4 Oxidative Prins-Pinacol Rearrangement4.5 Oxidative Prins-Type Reaction4.6 Total Synthesis of (–)-Fortucine4.7 Total Synthesis of Isostrychnine4.8 Total Synthesis of (–)-Strychnopivotine5 Development of a Functional Protecting Group

The effect of the new hemostatic agent Ostene® on bone healing: An experimental study in rabbits

Introduction: Ostene® is a water-soluble wax-like alkylene oxide copolymer preparation for use as a mechanical hemostatic agent. This study aims to evaluate the effects of Ostene® on bone healing. Materials and Methods: Twenty albino rabbits were divided into four groups according to post-treatment follow-up (24 hr, 3 days, 7 days, 14 days) with five rabbits in each group. Each rabbit in all groups was treated with two study materials (Ostene® and Gelfoam®). Three holes were made in the mandibular bone of each rabbit using 5mm surgical bur; two holes were made on right side: one for testing Ostene® and another for Gelfoam®. A third hole, on the left side of mandible, was not treated, and was used as a control. Finally, the incision was closed. The specimens were collected at different days post-treatment and examined by histopathology. Result and Discussion: This study showed that there is a significant difference (p-value≤ 0.05) between the Ostene® group and the other groups (Gelfoam® and control). At 24 hr post intervention, there is a significant difference in osteoblast cell formation (p-value=0.03), and osteoclast cell formation (p-value=0.05). New blood vessel formation, osteoblast and osteoclast cell formation for Ostene® group at 3 days post-intervention were also significantly different (p-values = 0.05, 0.03, 0.04, respectively). At 7 days post-intervention p-values were 0.05 for osteoblast formation and 0.04 for osteoclast formation, respectively. After 14 days of healing p-value for osteoblast cell formation in the Ostene® group was 0.05 and 0.04 for osteoclast cell formation. Conclusions: The bone hemostatic agent Ostene® is an effective at enhancing osteogenesis by initiating proliferation of osteoblast and osteoclast cells.

Visible-Light-Enabled Oxidative Alkylation of Unactivated Alkenes with Dimethyl Sulfoxide through Concomitant 1,2-Aryl Migration.

Metal-free oxidative radical 1,2-alkylarylation of unactivated alkenes with the α-C(sp3)-H bond of dimethyl sulfoxide has been developed. This study realizes a new, conceptually novel technology for convenient construction of a variety of α-aryl-γ-methylsulfinyl ketones in good-to-excellent yields with the synergistic interactions of visible light irradiation, organic fluorophores 4CzIPN, and hypervalent iodine(III) reagent under transition-metal free conditions. A remarkable kinetic isotope effect was observed, which helped provide insight into the reaction's mechanistic course.

The Effect of New Haemostatic Agent Ostene® on Bone Healing (A Comparative Experimental Study)

ABSTRACT Introduction: Ostene ® is a bone wax-like preparation of water-soluble wax (WSW). It is an alkylene oxide copolymers mechanical haemostatic agent. This study aims to evaluate the effects of Ostene ® on bone healing. Materials and Methods: Twenty albino rabbits were randomized into three groups according to study materials into [Ostene, gelfoam, control (no material applied)]. Each group was subdivided into 4 groups according to healing periods (24h., 3days, 7days, 14 days). Three holes were made in mandible of each rabbit. Two holes were made on one side and third hole on the other side of mandible using 5mm surgical bur. Finally, the incision was closed. The specimens were collected and examined histopathologicaly. Result and Discussion: This study showed that there is a significant difference between ostene group and other groups in which P -value was ≤ 0.05. During 24h of healing, there is a significant difference in osteoblast cell formation in which P -value was 0.03 and osteoclast cell formation P -value was 0.05. New blood vessel formation, osteoblast and osteoclast cell formation for ostene group during 3days of healing P -value was 0.05, 0.03, 0.04 respectively .In 7days of healing P -value was 0.05 for osteoblast cell and 0.04 for osteoclast cell. In 14 days of healing P -value of ostene in osteoblast cell formation was 0.05 and osteoclast cell formation was 0.04. Conclusions: Ostene bone haemostatic agent is an effective agent that enhances osteogenesis by initiating proliferation of osteoblast and osteoclast cells.

Study on flame retardant ABS

Flame-retardant ABS resin was prepared by adding fl ame retardant, toughening agent and dispersing silicone oilwith acrylonitrile-butadiene-styrene resin (ABS, grade 0215 A) as raw material. The results showed that in the ABSresin, fl ame retardant with tetrabromobisphenol A and antimony trioxide as the composite system (the mass ratio of2:1) was added. When the bromine content of the system was more than 10%, the flame retardant ABS meets therequirements of UL 94 V-0. The best toughening agent for flame retardant ABS resin is ABS graft powder. Whenthe amount of fl ame retardant ABS is 9% ~ 19% (mass fraction) Strength of 150-200 J / m; in the same formula andoperating conditions, brominated alkylene oxide as fl ame retardant prepared fl ame retardant ABS resin, the weatherresistance is better than tetrabromobisphenol A as fl ame retardant The Composite expansion fl ame retardant and coatedred phosphorus is an eff ective halogen-free fl ame retardant.

KMnO4/guanidinium-based sulfonic acid: as an efficient Brønsted acid organocatalyst for the selective oxidation of organic compounds

ABSTRACTKMnO4/guanidinium-based sulfonic acid as a green organocatalytic oxidative system can be used effectively for the selective oxidation of organic compounds in n-hexane as a nonpolar and inert solvent at room temperature in good yields. The use of this approach is described for the oxidation of alkyl arenes, alcohols, and sulfides.

Catalytic Systems Based on Magnesium and Zinc Compounds in the Oxidation Reactions of Alkylarenes and the Decomposition Reactions of the Corresponding Hydroperoxides

The oxidation of aromatic hydrocarbons in the presence of magnesium and zinc 2-ethylhexanoates and a mixed catalyst based on these compounds is studied. It is shown that magnesium and zinc carboxylates are active catalytic systems which catalyze the decomposition of hydroperoxides representing the primary alkylarene oxidation products alongside with activation of oxygen.

Visible-Light-Mediated Synthesis of Ketones by the Oxidative Alkylation of Styrenes.

The oxidative coupling of photogenerated alkyl radicals with readily available styrenes is disclosed. This visible-light-mediated method allows rapid access to a wide range of α-alkyl-acetophenones in good yields and with high functional group tolerance. In addition, the developed protocol features room temperature conditions, low photocatalyst loadings, and the use of dimethyl sulfoxide as nontoxic and mild terminal oxidant.

Highly selective aerobic oxidation of alkylarenes catalyzed by cobalt‐based nanocatalyst in aqueous solution

The catalytic aerobic oxidation of alkylarenes catalyzed by cobalt supported on a highly crystalline γ‐Al2O3 support (Co/Al2O3 nanocatalyst) is reported. The catalyst was prepared by a co‐precipitation method and characterized using scanning and high‐resolution transmission electron microscopies, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction and surface area measurements. A wide range of alkylarenes were converted to corresponding ketones. The catalyst can be recovered by simple filtration is recyclable for up to six consecutive runs.

Synthesis and characterization of novel alkoxy nonionic biosurfactants

ABSTRACTA series of novel alkoxy nonionic biosurfactants were synthesized by ring-opening reaction of methoxy poly(ethylene glycols) and alkylene oxide. The chemical structures of these biosurfactants were confirmed by Fourier-transform infrared spectroscopy (FTIR) and 1HNMR spectra. The surface tensions of these nonionic biosurfactants in the aqueous solutions were determined using a surface tensionmeter. The results showed that the critical micelle concentrations decreased with the increase of hydrophobic chain. However, due to the effect of intermolecular hydrogen bonding, the critical surface tensions of these nonionic biosurfactants increased with increasing the hydrophobic chain and were lower than those of conventional nonionic biosurfactants. Meanwhile, the effects of electrolytes on surface tension of these nonionic biosurfactants were slight. Due to the excellent surface activity, these alkoxy nonionic biosurfactants could have great potential in cleansing, oil recovery, and drug delivery.