p38α mitogen-activated protein kinase (MAPK) plays a role in several cellular processes and consequently has been a therapeutic target in inflammatory diseases, cancer, and cardiovascular disease. A number of known p38α MAPK inhibitors contain vicinal 4-fluorophenyl/4-pyridyl rings connected to either a 5- or 6-membered heterocycle. In this study, a small library of substituted thiophene-based compounds bearing the vicinal 4-fluorophenyl/4-pyridyl rings was designed using computational docking as a visualisation tool. Compounds were synthesised and evaluated in a fluorescence polarisation binding assay. The synthesised analogues had a higher binding affinity to the active phosphorylated form of p38α MAPK than the inactive nonphosphorylated form of the protein. 4-(2-(4-fluorophenyl)thiophen-3-yl)pyridine had a K_i value of 0.6 μm to active p38α MAPK highlighting that substitution of the core ring to a thiophene retains affinity to the enzyme and can be utilised in p38α MAPK inhibitors. This compound was further elaborated using a substituted phenyl ring in order to probe the second hydrophobic pocket. Many of these analogues exhibited low micromolar affinity to active p38α MAPK. The suppression of neonatal rat fibroblast collagen synthesis was also observed suggesting that further development of these compounds may lead to potential therapeutics having cardioprotective properties.

Noscapine, a phthalideisoquinoline alkaloid derived from Papaver somniferum, is a well-known antitussive drug that has a relatively safe in vitro toxicity profile. Noscapine is also known to possess weak anticancer efficacy, and since its discovery, efforts have been made to design derivatives with improved potency. Herein, the synthesis of a series of noscapine analogues, which have been modified in the 6′, 9′, 1 and 7-positions, is described. In a previous study, replacement of the naturally occurring N-methyl group in the 6′-position with an N-ethylaminocarbonyl was shown to promote cell-cycle arrest and cytotoxicity against three cancer cell lines. Here, this modification has been combined with other structural changes that have previously been shown to improve anticancer activity, namely halo substitution in the 9′-position, regioselective O-demethylation to reveal a free phenol in the 7-position, and reduction of the lactone to the corresponding cyclic ether in the 1-position. The incorporation of new aryl substituents in the 9′-position was also investigated. The study identified interesting new compounds able to induce G2/M cell-cycle arrest and that possess cytotoxic activity against the human prostate carcinoma cell line PC3, the human breast adenocarcinoma cell line MCF-7, and the human pancreatic epithelioid carcinoma cell line PANC-1. In particular, the ethyl urea cyclic ether noscapinoids and a compound containing a 6′-ethylaminocarbonyl along with 9′-chloro, 7-hydroxy and lactone moieties exhibited the most promising biological activities, with EC₅₀ values in the low micromolar range against all three cancer cell lines, and these derivatives warrant further investigation.

Heterobivalent ligands that possess pharmacophores designed to interact with both the A₁ adenosine receptor (A₁AR) and the β₂ adrenergic receptor (β₂AR) were prepared. More specifically, these ligands contain an adenosine moiety that is linked via its N⁶-position to the amino group of the saligenin-substituted ethanolamine moiety present in the well-known β₂AR agonist, salbutamol. The affinities of these ligands were determined at both receptors and found to vary with linker length and composition. With all compounds, affinity and functional potencies were found to have selectivity for the A₁AR over the β₂AR. In all cases, cAMP accumulation (a β₂AR-mediated response) was mainly observed when the A₁AR was blocked or its function decreased by pertussis toxin or chronic agonist treatment. This suggests that heterobivalent compounds for receptors that mediate opposite responses might be useful for elucidating the mechanisms of receptor cross-talk and how this interaction, in terms of responsiveness, may change under pathophysiological conditions.

Noscapine is a phthalideisoquinoline alkaloid isolated from the opium poppy Papaver somniferum. It has long been used as an antitussive agent, but has more recently been found to possess microtubule-modulating properties and anticancer activity. Herein we report the synthesis and pharmacological evaluation of a series of 6′-substituted noscapine derivatives. To underpin this structure–activity study, an efficient synthesis of N-nornoscapine and its subsequent reduction to the cyclic ether derivative of N-nornoscapine was developed. Reaction of the latter with a range of alkyl halides, acid chlorides, isocyanates, thioisocyanates, and chloroformate reagents resulted in the formation of the corresponding N-alkyl, N-acyl, N-carbamoyl, N-thiocarbamoyl, and N-carbamate derivatives, respectively. The ability of these compounds to inhibit cell proliferation was assessed in cell-cycle cytotoxicity assays using prostate cancer (PC3), breast cancer (MCF-7), and colon cancer (Caco-2) cell lines. Compounds that showed activity in the cell-cycle assay were further evaluated in cell viability assays using PC3 and MCF-7 cells.

A concise synthesis of a series of N⁶-substituted adenosines with bicyclo[3.2.1]octan-6-yl and polycyclic N⁶-substituents has been developed. The adenosine A₁ receptor (A₁R) affinity and potency of these compounds was initially assessed using competitive binding assays and cyclic adenosine monophosphate (cAMP) accumulation assays in DDT₁ MF-2 cells. The potency and receptor subtype selectivity of selected examples was further evaluated by measuring their effects on cAMP accumulation at all human adenosine receptor subtypes expressed in CHO cells. The results of these assays indicated that all of the synthesised N⁶-substituted adenosines are full agonists at A₁R and activate this receptor selectively over the other adenosine receptor subtypes. The two standout compounds in terms of potency were N⁶-(3-thiabicyclo[3.2.1]octan-6-yl)adenosine and N⁶-(cubanylmethyl)adenosine with EC₅₀ values at human A₁R of 2.3 nM and 1.1 nM, respectively. The cubanylmethyl derivative in particular proved to be highly receptor subtype selective. These two compounds were further evaluated in a simulated ischaemia model in cultured cardiomyoblasts, where they were found to impart protective effects under hypoxic conditions that resulted in a significant reduction in cell death.

Alkylpyridinium (10a, R = Me and 10b, R = Et) and tetraalkylphosphonium (19) ionic liquids which possess ether functionality were prepared and evaluated as solvents and co-solvents for Grignard reactions. Interestingly, reduction of the starting aldehydes to the corresponding primary alcohol was the favored pathway when reactions were conducted in pyridinium ILs 10a, b in the absence an ethereal co-solvent. However, the same reactions in the phosphonium IL 19 afforded the expected Grignard products in good yield in cases where diethyl ether was present as a co-solvent.

An efficient synthesis of 2-halo-O⁶-(benzotriazol-1-yl)-substituted purine nucleosides has been accomplished via (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP)-mediated coupling and subsequent halogenation via diazotization of the 2-amino group of various protected guanosines and directly from guanosine itself. These products are amenable to substitution and coupling reactions in the 2- and 6-positions and, accordingly, provide efficient access to highly functionalized purine nucleosides.