Exploring Flow Procedures for Diazonium Formation

University of Durham

Abstract

The synthesis of diazonium salts is historically an important transformation extensively utilized in dye manufacture. However the highly reactive nature of the diazonium functionality has additionally led to the development of many new reactions including several carbon-carbon bond forming processes. It is therefore highly desirable to determine optimum conditions for the formation of diazonium compounds utilizing the latest processing tools such as flow chemistry to take advantage of the increased safety and continuous manufacturing capabilities. Herein we report a series of flow-based procedures to prepare diazonium salts for subsequent in-situ consumption.

Flow reactor loading set-up.

 

Direct in-line mass spec analysis was performed using the Advion Interchim Scientific® expression® Compact Mass Spectrometer (CMS) with electrospray ionization (ESI).

Expanding the Scope of Sortase‐Mediated Ligations by Using Sortase Homologues

Western Washington University

Abstract

Sortase‐catalyzed transacylation reactions are widely used for the construction of non‐natural protein derivatives. However, the most commonly used enzyme for these strategies (sortase A from Staphylococcus aureus) is limited by its narrow substrate scope. To expand the range of substrates compatible with sortase‐mediated reactions, we characterized the in vitro substrate preferences of eight sortase A homologues.
From these studies, we identified sortase A enzymes that recognize multiple substrates that are unreactive toward sortase A from S. aureus.
We further exploited the ability of sortase A from Streptococcus pneumoniae to recognize an LPATS substrate to perform a site‐specific modification of the N‐terminal serine residue in the naturally occurring antimicrobial peptide DCD‐1L.
Finally, we unexpectedly observed that certain substrates (LPATXG, X=Nle, Leu, Phe, Tyr) were susceptible to transacylation at alternative sites within the substrate motif, and sortase A from S. pneumoniae was capable of forming oligomers. Overall, this work provides a foundation for the further development of sortase enzymes for use in protein modification.

Mass spectrometry analysis was performed using the Advion Interchim Scientific® expression® Compact Mass Spectrometer (CMS).

Design, synthesis and anti-HIV activity of novel quinoxaline derivatives

Nirma University, India; Rega Institute for Medical Research

Abstract

In order to design novel anti-HIV agents, pharmacophore modelling, virtual screening, 3D-QSAR and molecular docking studies were performed. 50 quinoxaline derivatives with different substitutions were designed on basis of both ligand based drug design approaches and were mapped on the best pharmacophore model. From this, best 32 quinoxaline derivatives were docked onto the active site of integrase enzyme and in-silico ADMET properties were also predicted. From this data, synthesis of top 7 quinoxaline derivatives was carried out and were characterized using Mass, 1H-NMR and 13C-NMR spectroscopy. Purity of compounds were checked using HPLC.
Two quinoxaline derivatives showed good results, which can be further explored to develop novel anti-HIV agents.

Cytotoxic gallium complexes containing thiosemicarbazones derived from 9-anthraldehyde: Molecular docking with biomolecules

Lyon College, University of Rhode Island

Abstract

MOLSTR, Accepted manuscript. doi:10.1016/j.molstruc.2016.05.075

 

We have synthesized a trio of gallium complexes bearing 9-anthraldehyde thiosemicarbazones. The complexes were assessed for their anticancer activity and their biophysical reactivity was also investigated.

The results of docking studies with DNA, ribonucleotide reductase and human serum albumin, however showed that the complex with the best biological activity had the largest binding constant to DNA.

Electrospray ionization mass spectrometry (ESI-MS) was recorded using the Advion expression Compact Mass Spectrometer (CMS).

Characterization of Endogenous Sodium Channels in the ND7-23 Neuroblastoma Cell Line: Implications for Use as a Heterologous Ion Channel Expression System Suitable for Automated Patch Clamp Screening

Xention Limited, United Kingdom; University of Ljubljana, Slovenia

Abstract


The rodent neuroblastoma cell line, ND7-23, is used to express voltage-dependent sodium (Nav) and other neuronal ion channels resistant to heterologous expression in Chinese hamster ovary (CHO) or human embryonic kidney (HEK) cells. Their advantage is that they provide endogenous factors and signaling pathways to promote ion channel peptide folding, expression, and function at the cell surface and are also amenable to automated patch clamping. However, ND7-23 cells exhibit endogenous tetrodotoxin (TTX)-sensitive Nav currents, and molecular profiling has revealed the presence of Nav1.2, Nav1.3, Nav1.6, and Nav1.7 transcripts, but no study has determined which subtypes contribute to functional channels at the cell surface. In this publication, we profiled the repertoire of functional Nav channels endogenously expressed in ND7-23 cells using the QPatch automated patch clamp platform and selective toxins and small molecules.

Mass spec analysis was performed using the Advion expression Compact Mass Spectrometer (CMS).

Angelica dahurica Extracts Improve Glucose Tolerance through the Activation of GPR119

Mokpo National University, Gachon University, Hanyang University, Gachon Medical Research Institute, South Korea; University of Bremen, Germany

Abstract

G protein-coupled receptor (GPR) 119 is expressed in pancreatic β-cells and intestinal L cells, and is involved in glucose-stimulated insulin secretion and glucagon-like peptide-1 (GLP-1) release, respectively. Therefore, the development of GPR119 agonists is a potential treatment for type 2 diabetes. In this publication,  screened 1500 natural plant extracts for GPR119 agonistic actions and investigated the most promising extract, that from Angelica dahurica (AD), for hypoglycemic actions in vitro and in vivo.

Electrospray ionization mass spectrometry (ESI-MS) data was measured using the Advion expression CMS

An efficient synthesis of novel carbohydrate and thiosemicarbazone hybrid benzimidazole derivatives and their antimicrobial evaluation

Gujarat University

Abstract

A library of thiosemicarbazide hybrid 2-(aldo-polyhydroxyalkyl)benzimidazole derivatives have been designed and synthesized with simple and eco-friendly methodologies. The structures of the compounds have been elucidated with the aid of elemental analysis, IR, mass and 1H NMR spectral data. These novel synthesized compounds have been evaluated for their antibacterial activity against two gram-positive bacteria (S. aureus and S. pyogenus) and two gram-negative bacteria (P. aeruginosa and E. coli). The title compounds have also been studied for their antifungal activity against C. albicans, A. niger and A. clavatus using the broth dilution technique.

Mass spec analysis was performed using the Advion expression Compact Mass Spectrometer (CMS) with electrospray ionization (ESI).

A Photolithographic Approach to Spatially Resolved Cross-Linked Nanolayers

Karlsruhe Institute of Technology

Abstract

The preparation of cross-linked nanosheets with 1–2 nm thickness and predefined shape was achieved by lithographic immobilization of trimethacryloyl thioalkanoates onto the surface of Si wafers, which were functionalized with 2-(phenacylthio)acetamido groups via a photoinduced reaction. Subsequent cross-linking via free radical polymerization as well as a phototriggered Diels–Alder reaction under mild conditions on the surface led to the desired nanosheets. Electrospray ionization mass spectrometry (ESI-MS), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), as well as infrared reflection-absorption spectroscopy (IRRAS) confirmed the success of individual surface-modification and cross-linking reactions.

ESI-MS analysis was performed using the Advion Interchim Scientific® expression® Compact Mass Spectrometer (CMS).

A One Pot, Solvent Free and Catalyst Free Synthesis of Substituted 2-Amino-5-Aryl-1,3,4-Oxadiazoles under Microwave Irradiation

Gujarat University

Abstract

A convenient one-pot, multi-component and solvent free procedure for the preparation of substituted 2-amino-5-aryl-1,3,4-oxadiazoles has been achieved. The method is a significant improvement over previously reported synthesis. Reaction of acid chlorides with hydrazine hydrate and isothiocynates under microwave-irradiation (MWI) afforded the corresponding 1,3,4-oxadiazole derivatives in high yields with high purity. All synthesized compounds were characterized by FT-IR, proton and carbon NMR, mass spectroscopy and elemental analysis. A possible mechanism is proposed for the cyclodesulfurization based on the results of this study.

Mass spec analysis was performed on the Advion expression Compact Mass Spectrometer (CMS) using electrospray ionization (ESI).

A Green One-Pot Multicomponent Synthesis of 4H-Pyrans and Polysubstituted Aniline Derivatives of Biological, Pharmacological, and Optical Applications Using Silica Nanoparticles as Reusable Catalyst

Guru Ghasidas University, University of South Dakota

A one-pot practical, efficient, and environmentally benign multicomponent synthesis of 4H-pyrans and polysubstituted aniline derivatives of biological, pharmacological, and optical applications has been developed using a very mild, neutral, and reusable silica nanoparticles as catalyst. The 4H-pyran derivatives were synthesized by a three component reaction of an aldehyde, malononitrile, and 5,5-dimethyl-1,3-cyclohexanedione or ethyl acetoacetate at room temperature or refluxing in ethanol. Alternatively, polysubstituted anilines were synthesized via a four component reaction of an aldehyde, a ketone, and two equivalents of malononitrile in ethanol.

Mass spec analysis was carried out using an Advion expression Compact Mass Spectrometer (CMS).