A biosynthetically-inspired synthetic route to substituted furans and its application to the total synthesis of the furan fatty acid f5

Dietary fish oil supplementation has long been shown to have significant health benefits, largely stemming from the anti-inflammatory activity of the ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) present in fish oils. The anti-inflammatory properties of these fatty acids has been linked to beneficial health effects, such as protecting the heart, in individuals consuming diets rich in fish, or supplemented with fish oils. These effects are highly notable in the Māori people native to coastal regions of New Zealand; the significantly lower rates of heart problems compared to the inland populous has been attributed to the consumption of the green lipped mussel Perna Canaliculus. Commercially available health supplements based on the New Zealand green lipped mussel include a freeze-dried powder and a lipid extract (Lyprinol®), the latter of which has shown anti-inflammatory properties comparable to classical non-steroidal anti-inflammatory drugs (NSAIDs) such as Naproxen. GCMS analysis of Lyprinol by Murphy et al. showed the presence of a class of ω-4 and ω-6 PUFAs bearing a highly electron rich tri- or tetra-alkyl furan ring, which were designated furan fatty acids (F-acids). Due to their instability, isolation of F-acids from natural sources cannot be carried out and a general synthetic route toward this class of natural products was required. To accomplish this, the biosynthesis of F-acids was mimicked by utilising an oxidation of 1,3-dienes, followed by a dehydration/aromatisation to generate the heterocyclic furan ring. Singlet oxygen was chosen as the means of oxidising the conjugated dienes giving endoperoxides. To mimic the biological aromatisation of the peroxide intermediates the Appel reagent was chosen and, in a novel application of the reagent, was exploited as a mild, metal free method of dehydrating the cyclic peroxides to their corresponding furans. The biomimetic furan synthesis was applied toward a selection of 1,3-diene substrates bearing a range of pre-installed functionalities and substitution patterns including alkyl, aryl, alkenes, cyclopropyl rings, silyl ethers, and esters, alongside being applied to the total synthesis of the furan fatty acid F5. A brief exploration of the possibility of performing the aromatisation reaction under catalytic conditions was carried out, to determine whether endoperoxides could be converted to furans without needing a stoichiometric quantity of Appel reagent, by harnessing a catalytic quantity of triphenylphosphine oxide and regenerating the active P(V) species via reaction with oxalyl chloride. Furthermore, an optimisation study was carried out using a simple design of experiments procedure to ascertain the ideal conditions for carrying out the Appel-type dehydration of endoperoxides. Finally, the scope of the reaction sequence was expanded to be performed in a continuous flow reactor, with telescoping of the singlet oxygen diene oxidation and Appel-type aromatisation to increase oxidation yields and to omit the requirement for isolation of peroxide intermediates, and was applied to the synthesis of a selection of 2,5-diaryl furan motifs

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Illuminant spectral power distributions and diffuse spectral reflectances used in experiment stimul

DataSheet_1_Loss of CFTR function is associated with reduced bitter taste receptor-stimulated nitric oxide innate immune responses in nasal epithelial cells and macrophages.pdf

IntroductionBitter taste receptors (T2Rs) are G protein-coupled receptors identified on the tongue but expressed all over the body, including in airway cilia and macrophages, where T2Rs serve an immune role. T2R isoforms detect bitter metabolites (quinolones and acyl-homoserine lactones) secreted by gram negative bacteria, including Pseudomonas aeruginosa, a major pathogen in cystic fibrosis (CF). T2R activation by bitter bacterial products triggers calcium-dependent nitric oxide (NO) production. In airway cells, the NO increases mucociliary clearance and has direct antibacterial properties. In macrophages, the same pathway enhances phagocytosis. Because prior studies linked CF with reduced NO, we hypothesized that CF cells may have reduced T2R/NO responses, possibly contributing to reduced innate immunity in CF.MethodsImmunofluorescence, qPCR, and live cell imaging were used to measure T2R localization, calcium and NO signaling, ciliary beating, and antimicrobial responses in air-liquid interface cultures of primary human nasal epithelial cells and immortalized bronchial cell lines. Immunofluorescence and live cell imaging was used to measure T2R signaling and phagocytosis in primary human monocyte-derived macrophages.ResultsPrimary nasal epithelial cells from both CF and non-CF patients exhibited similar T2R expression, localization, and calcium signals. However, CF cells exhibited reduced NO production also observed in immortalized CFBE41o- CF cells and non-CF 16HBE cells CRISPR modified with CF-causing mutations in the CF transmembrane conductance regulator (CFTR). NO was restored by VX-770/VX-809 corrector/potentiator pre-treatment, suggesting reduced NO in CF cells is due to loss of CFTR function. In nasal cells, reduced NO correlated with reduced ciliary and antibacterial responses. In primary human macrophages, inhibition of CFTR reduced NO production and phagocytosis during T2R stimulation.ConclusionsTogether, these data suggest an intrinsic deficiency in T2R/NO signaling caused by loss of CFTR function that may contribute to intrinsic susceptibilities of CF patients to P. aeruginosa and other gram-negative bacteria that activate T2Rs.</p

A Novel Isoquinoline Derivative Anticancer Agent and Its Targeted Delivery to Tumor Cells Using Transferrin-Conjugated Liposomes

<div><p>We have screened 11 isoquinoline derivatives and α-methylene-γ-butyrolactones using the 3-(4,5-dimethylthi-azol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay in HeLa and HEK-293T cells. Compound 2 was identified as potential anticancer agent. To further improve its therapeutic potential, this agent was incorporated into transferrin (Tf)-conjugated liposomes (LPs) for targeted delivery to tumor cells. We have demonstrated Tf-LP-Compound 2 have superior antitumor activity compared to non-targeted controls and the free drug. These data show Tf-LP-Compound 2 to be a promising agent that warrants further evaluation.</p></div

In vitro release of LP-Compound 2, Tf-LP-Compound 2 and free Compound 2.

<p>Drug release during 24 h incubation in PBS (0.5%v/v Tween 80) at 37 degree C, mean SD values (n = 3) are presented.</p

Fluorescence image of HeLa and HepG2 cells stained with JC-1.

<p>(A)Photograph showing JC-1 red, JC-1 green and merge image. (B)Numerical data were expressed in terms of the ratio of JC-1 aggregates to JC-1 monomers. Data are representative of three independent experiments and expressed as means ±SD, *p, 0.05, **p, 0.01 and ***p, 0.001 as compared with the control.</p

Cytotoxicity tests of compounds by MTT assay.

<p>Cells were treated with various compounds for 4h, and grown for another 20h. (A)IC50 of HeLa and HepG2 cells (B)HEK-293T cells Data represent the mean± standard deviation (n = 6).</p

FE-SEM images of Tf-LP-Compound 2.

<p>FE-SEM images of Tf-LP-Compound 2.</p

Cellular uptake of LP-Compound 2 and Tf-LP-Compound 2.

<p>Flow cytometry after incubation of LP-Compound 2, Tf-LP-Compound 2 and Tf-LP-Compound 2 with holo Tf. Data represent the mean± standard deviation (n = 3)(**p<0.01 vs LP-Compound 2).</p

Size, ζ-potential and Encapsulation efficiency of LPs before and after coupling of Tf at pH 7.4.

<p>Data are shown as means and standard deviation (n = 3).</p