: Increased glucose and choline uptake are hallmarks of cancer. We investigated if the uptake and conversion of [2H9]choline alone and together with that of [6,6’ 2H2]glucose can be assessed in subcutaneous tumors by deuterium metabolic imaging (DMI) after bolus administration of these compounds. Therefore tumors with human renal carcinoma cells were grown subcutaneously in mice up to ~0.5 cm3. Mice were anesthetized with isoflurane and IV infused in the MR magnet for ~20 sec with ~0.2 ml solutions containing either [2H9]choline (0.05g/kg) alone or together with [6,6’ 2H2]glucose (1.3g/kg). 2H MR was performed on a 11.7T MR system with a home-built 2H/1H coil using a 900 excitation pulse and 400ms repetition time. 3D DMI was recorded at high resolution (2x2x2mm) in 37 min or at low resolution (3.7x3.7x3.7mm) in 2:24 min. Absolute tissue concentrations were calculate assuming initial [HOD]=13.7mM. Within 5 minutes after [2H9]choline infusion its signal appeared in tumor spectra representing concentration increasing up to 0.3–1.2 mM and then slowly decreased or remained constant over 100 minutes. In plasma [2H9]choline disappeared within 15 minutes post-infusion implying that its tumor signal arises from tissue and not blood. After infusing a mixture of [2H9]choline and [6,6’ 2H2]glucose their signals were observed separately in tumor 2H spectra. Over time the [2H9]choline signal broadened, possibly due to conversion to other choline compounds, [[6,6’ 2H2]glucose] declined, [HOD] increased and a lactate signal appeared, reflecting glycolysis. Metabolic maps of all 2H compounds were reconstructed from high resolution DMIs. As choline infusion and glucose DMI is feasible in patients, their simultaneous detection has clinical potential for tumor characterization.

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) from the group of phenylacetic acid derivatives, which has analgesic, anti-inflammatory and antipyretic properties. The interaction of non-steroidal anti-inflammatory drugs with cell membranes can affect their physicochemical properties, which, in turn, can cause a number of side effects in the use of these drugs. Electron paramagnetic resonance (EPR) spectroscopy could be used to study the interaction of diclofenac with the membrane, if its spin-labeled analogs existed. This paper describes the synthesis of spin-labeled diclofenac (diclofenac-SL), which consists of a simple sequence of transformations such as iodination, esterification, Sonogashira cross-coupling, oxidation and saponification. EPR spectra showed that diclofenac-SL binds to in a lipid membrane composed of palmito-yl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). 2H electron spin echo spectroscopy (ESEEM) was used to determine the position of the diclofenac-SL relative to the membrane surface. It has been established that the average its depth of immersion corresponds to the 5th position of the carbon atom in the lipid chain.

A Multicomponent Reaction (MCR) strategy, alternative to the known cycloaddition reaction, towards variously substituted 1-amino-1H-imidazole-2(3H)-thione derivatives has been successfully developed. The novel approach involves α-halohydrazones whose azidation process followed by tandem Staudinger/aza-Wittig reaction with CS₂ in a sequential MCR regioselectively leads to the target compounds avoiding the formation of the regioisomer iminothiazoline heterocycle. The approach can be applied to a range of differently substituted α-halohydrazones bearing also electron-withdrawing groups confirming the wide scope and the substituent tolerance of the process for the synthesis of the target compounds. Interestingly, the concurrent presence of reactive functionalities in the scaffolds so obtained, ensures postmodifications in view of N-bridgedheaded heterobicyclic structures.

2-(Adamantan-1-yl)-2H-isoindole-1-carbonitrile (1) has been identified as a neurobiological fluorescent ligand that may be used to develop receptor and enzyme binding affinity assays. Compound 1 was synthesised using an optimised microwave irradiation reaction and crystallised from ethanol. Crystallization occurred in the orthorhombic space group P212121 with unit cell parameters: a = 6.4487(12) Å, b = 13.648(3) Å, c = 16.571(3) Å, V = 1458(5) Å3, Z = 4. Density functional theory (DFT) (B3LYP/6-311++G (d,p)) calculations of 1 were carried out. Results showed that the optimised geometry is similar to the crystal structure parameters with a root-mean-squared deviation of 0.143 Å. Frontier molecular orbital energies and net atomic charges are discussed with a focus on potential biological interactions. Docking experiments within the active site of the neuronal nitric oxide synthase (nNOS) protein crystal structure were carried out and analysed. Important binding interactions between the DFT optimised structure and amino acids within the nNOS active site were identified that explain the strong NOS binding affinity reported. Fluorescent properties of 1 were studied using aprotic solvents of different polarities. Compound 1 showed the highest fluorescence intensity in polar solvents with excitation and emission values of 336 nm and 380 nm, respectively.