Harrison C. Daly, Gonzalo Sampedro, Corentin Bon, Dan Wu, Ghazi Cahill, Roman A. Cahill, Donal F. O’Shea
The use of near-infrared fluorescence for in vivo research and intraoperative clinical imaging is rapidly expanding, with new applications being proposed and developed. While imaging hardware and software have significantly progressed in recent times, the molecular fluorescent agents remain a limiting factor. In this report, the design, synthesis, photophysical characterization and bio-medical imaging assessment of two new NIR-fluorophores based on the BF2-azadipyrromethene fluorophore class are described. Inclusion of dimethylamino substituents on these BF2-azadipyrromethene probes results in very large bathochromic shifts with photophysical measurements showing absorption and emission maxima between 757 and 818 nm within the desired NIR spectra region. Testing of the probes shows that they are suitable for fluorescence imaging with both research and clinical instrumentation. Preclinical imaging assessment shows their suitability as fluorescent markers (tattoos) of lesions for intraoperative identification and lymphatic mapping in ex vivo human colonic tissue. These new clinical wavelength-compatible fluorophores may contribute towards the on-going expansion of medical uses for NIR-fluorescence.
The LC/MS analysis was carried out using Advion Expression® CMS.
UV-cured transparent acrylic pressure sensitive adhesives (PSAs) composed of semi-interpenetrating networks were prepared using the menthyl acrylate (MnA) and tetrahydro-geraniol acrylate (TGA) synthesized from menthol and tetrahydro geraniol, respectively. This study investigated the adhesion performance and environmental reliability of the resulting acrylic PSAs by changing the mole ratio for MnA and TGA while fixing the mole ratio for 2-hydroxyehtyl acrylate (2-HEA) in the PSAs. Also, the optical properties of the acrylic PSAs for optically clear adhesive applications were examined by UV–Vis spectroscopy, color-difference meter, and haze meter. All acrylic PSAs exhibited high transparency (>92%) and stable weatherability under reliability testing (85/85 test), regardless of the various comonomer compositions. The resulting acrylic PSAs showed proper adhesion performance to be allowed to use as optically clear adhesive; 180° peel strength of 1.6–4.0 kgf/25 mm, probe tack of 0.25–0.43 kgf, and shear holding power of 0.10–0.17 mm.
The MS analysis was carried out using Advion Expression® CMS.
Martin Doert, Stephanie Krüger, Gertrud E. Morlock, Lothar W. Kroh
Ternary mixtures of lecithins, vitamin C and vitamin E are powerful antioxidants for the stabilization of polyunsaturated (n-3 fatty acid) oils. In this study, the chemistry of the antioxidant synergistic effect was investigated in ethyl linoleate (EL) containing α-tocopherol (α-Toc) or in linoleate rich vegetable oils at 110 °C using mixtures of phosphatidylethanolamine (PE) and either l-ascorbic acid (AA) or l-dehydroascorbic acid (DHA). The highest stabilization effects in EL were similar in both systems and were found in the molar mixtures of PE and AA or DHA. The thermal formation of reaction products between PE and AA (PE–AA) or DHA (PE–DHA) were investigated by HPTLC/ESI-MS. When α-tocopherylquinone (α-TQ) was used instead of α-Toc, nearly the same antioxidant effect was observed in the EL system. It was shown that molar mixtures of PE and AA, or PE and DHA, can regenerate α-TQ to α-Toc at elevated temperatures. PE–AA was synthesized and tested as antioxidants in EL containing α-Toc and in vegetable oils at room temperature. An improved stabilization was observed with the synthesized derivative compared to the physical mixture of the compounds, which demonstrated that PE–AA is a potential new antioxidant. A mechanism for the synergistic action between PE, AA and α-Toc through an acid-catalysed regeneration of α-TQ is suggested. PE–AA is an active apolar antioxidant, which is involved in the reduction of α-TQ.
The MS analysis was carried out using Advion Expression® CMS TLC and ESI.
Rajesh H. Vekariya, Kinjal D. Patel, Dhanji P. Rajani, Smita D. Rajani, Hitesh D. Patel
A convenient, one-pot, multi-component protocol for the preparation of 2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinecarbothioamide derivatives has been achieved. Here, firstly we have reported the synthesis of 3-acetyl-2H-chromen-2-one using starch sulfuric acid and cellulose sulfuric acid as biodegradable catalysts. Subsequently, we also carried out the reaction of isothiocynates, hydrazine hydrate and 3-acetyl-2H-chromen-2-one in the presence of catalytic amount of glacial acetic acid in refluxing ethanol to afford corresponding 2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinecarbothioamide derivatives in high to excellent yields. All synthesized compounds were screened for antimicrobial activity. All compounds were found to show good to excellent activity against Escherichia coli MTCC 443.
Using the tetrahydro-geraniol acrylate (TGA) synthesized from biomass tetrahydro-geraniol, UV-cured transparent acrylic pressure sensitive adhesives (PSAs) composed of semi-interpenetrating networks were successfully fabricated. The utility for optically clear adhesive on adhesion performances according to various concentrations of TGA in the acrylic PSAs were investigated. After characterizing the photo-polymerized PSA syrups, the optical properties for the acrylic PSA films were examined using UV–vis spectroscopy, a color-difference meter, and a haze meter. The acrylic PSAs exhibited high transparency and stable weather-ability under reliability testing (85/85 test). With increasing TGA concentration in the acrylic PSAs, adhesion properties such as the 180° peel strength, shear holding power, and probe tack had decreased.
The LC/MS analysis was carried out using Advion Expression® CMS.
Til Bahadur Thapa Magar, Tara Man Kadayat, Hye Jin Oh, Pil-Hoon Park, Eun-Seok Lee
Chromanone-containing compounds have been reported to possess several important biological activities. As a part of our continuing effort for discovering potent anti-inflammatory agents, a series of halogen-containing 3-benzylidenechroman-4-ones (1–15) were synthesized, and evaluated for their inhibitory effect on lipopolysaccharide (LPS)-stimulated reactive oxygen species (ROS) production in RAW 264.7 macrophages. Compounds 4 and 10 exhibited significant inhibitory activity (IC50 = 5.09 ± 1.27 and 5.11 ± 0.51 μM, respectively) against LPS-stimulated ROS production in RAW 264.7 macrophages.
The LC/MS analysis was carried out using Advion Expression® CMS ESI.
Explosive and Pollutant Nitro Aromatics (epNACs) like 2,4,6-trinitrophenol (TNP) has been detected from various surface water specimens by luminescent Schiff base Organic Frameworks (SOFs) by fluorometric method. Fluorescence intensity of the receptor SOFs have been quenched in presence of TNP due to RET and ICT, which has been confirmed through solid and solution level spectroscopic studies like FT-IR, 1H-NMR, fluorescence titration. Modern DFT (DFT-D3) calculations of the possible host guest conformers have been performed for exploration of plausible route of interaction between receptor and epNACs. The outcome of theoretical calculations is in line with experimental findings where TNP and receptor conformation mimic parallel displaced type π- π interaction. TD-DFT has been executed with both receptor and receptor ···TNP adduct, the fluorescence quenching is in line with experimental outcome. Limit of TNP detection has been found as low as 5 μM with 2.97×104 M-1 as binding constant. In real time stepping, TNP as mutagenic agent for aquatic life has been detected inside prokaryotic cells like candidia albicans in ppm level.
The MS analysis was carried out using Advion Expression® CMS ESI.
Aaron L. Smith, Hasse Walum, Fawn Connor-Stroud, Sara M. Freeman, Kiyoshi Inoue, Lisa A. Parr, Mark M. Goodman, Larry J. Young
The physiology of the oxytocin receptor has increasingly become a focus of scientific investigation due to its connection with social behavior and psychiatric disorders with impairments in social funciton. Experimental utilization of small molecule and peptide antagonists for the oxytocin receptor has played a role in deciphering these biological and social behavior connections in rodents. Described herein is the evaluation of a potent and selective oxytocin receptor antagonist, ALS-I-41, and details to consider for its use in nonhuman primate behavioral pharmacology experiments utilizing intranasal or intramuscular administration. The central nervous system penetration and rate of metabolism of ALS-I-41 was investigated via mass spectroscopy analysis of cerebrospinal fluid and plasma in the rhesus macaque after intranasal and intramuscular administration. Positron emission tomography was also utilized with [18F] ALS-I-41 in a macaque to verify observed central nervous system (CNS) penetration and to further evaluate the effects of administration rate on CNS penetration of Sprague-Dawley rats in comparison to previous studies.
The LC/MS analysis was carried out using Advion Expression® CMS.
Additi Roy Chowdhury, Amita Mondal, Biswajit Gopal Roy, Jagadeesh C. Bose K, Sudit Mukhopadhyaye and Priyabrata Banerjee
Two novel hydrazine based sensors, BPPIH (N1, N3-bis(perfluorophenyl)isophthalohydrazide) and BPBIH (N1′, N3′-bis(perfluorobenzylidene)isophthalohydrazide), are presented here. BPPIH is found to be a highly sensitive pH sensor in the pH range 5.0 to 10.0 in a DMSO–water solvent mixture with a pKa value of 9.22. Interesting optical responses have been observed for BPPIH in the above mentioned pH range. BPBIH on the other hand turns out to be a less effective pH sensor in the above mentioned pH range. The increase in fluorescence intensity at a lower pH for BPPIH was explained by using density functional theory. The ability of BPPIH to monitor the pH changes inside cancer cells is a useful application of the sensor as a functional material. In addition fluoride (F−) selectivity studies of these two chemosensors have been performed and show that between them, BPBIH shows greater selectivity towards F−. The interaction energy calculated from the DFT-D3 supports the experimental findings. The pH sensor (BPPIH) can be further interfaced with suitable circuitry interfaced with desired programming for ease of access and enhancement of practical applications.
The MS analysis was carried out using Advion Expression® CMS ESI.
A: We provide our expertise, combining chromatography and mass spectrometry, as well as other Analytical techniques within the Facility. This facilitates and assists in the characterization of compounds synthesized in the Chemistry Department and a number of other departments within the University of Birmingham in addition to work for industrial collaborators.
Q: WHAT WAS YOUR PREVIOUS WORK FLOW OR CHALLENGES?
A: We needed a system capable of analysing reaction mixtures to assist in the identification of compounds of interest with minimal sample isolation required and provide a relatively quick identification of the compounds. The Advion TLC-MS has fully met these requirements, in terms of the ease of use as a walk-up instrument. This has greatly assisted in providing separation conditions in purification method development, as well as, a useful tool in simple reaction monitoring. The system has enabled us to directly obtain good quality data from complex mixtures of compounds. This has been of great benefit to research students across Chemistry, Chemical Engineering, Biochemistry and Pharmacology Departments who have all used the Advion TLC-MS. The major advantage of the Advion TLC-MS is the ability for the users to visualise the spot on the TLC that is being analysed by the mass spectrometer. If the sample requires further clean-up, the TLC conditions provide the initial starting point for upscaling purification using preparative columns.
Q: WHY DID YOU INCORPORATE THE EXPRESSION CMS INTO YOUR LABORATORY?
A: The Advion TLC-MS system is setup using an HPLC pump plumbed directly into the TLC sampler which is then plumbed back through the HPLC autosampler and finally into the Advion expression CMS. This setup has benefitted users to simply run a TLC and perform the MS analysis which takes just a few minutes and they have a lot of useful information about their reaction, product identity, impurities etc. The HPLC autosampler act as a method of directly delivering fractions collected from preparative HPLC allowing the users to quickly identify the fraction of interest. The feedback we have had is that by using the Advion TLC-MS the users are now spending significantly more time running reactions, increasing research output by spending less time isolating and characterizing each component in their reaction mixtures.
