Synthetic Toll-like Receptors 7 and 8 Agonists: Structure-Activity Relationship in the Oxoadenine Series.

Toll-like receptors 7 and 8 (TLR7/8) are broadly expressed on antigen-presenting cells, making TLR7/8 agonists likely candidates for the development of new vaccine adjuvants. We previously reported the synthesis of a new series of 8-oxoadenines substituted at the 9-position with a 4-piperidinylalkyl moiety and demonstrated that TLR7/8 selectivity and potency could be modulated by varying the length of the alkyl linker. In the present study, we broadened our initial structure-activity relationship study to further evaluate the effects of N-heterocycle ring size, chirality, and substitution on TLR7/8 potency, receptor selectivity, and cytokine (IFNα and TNFα) induction from human peripheral blood mononuclear cells (PBMCs).

Efficient tin-mediated synthesis of lysophospholipid conjugates of a TLR7/8-active imidazoquinoline.

The chemical synthesis of lysophospholipids often involves multiple synthetic and chromatographic steps due to the incorporation of the fatty acyl group onto the glycerol scaffold early in the synthesis. We report herein a new protocol for the lysophosphatidylation of alcohols and its application to the synthesis of lysophospholipid conjugates of TLR7/8-active imidazoquinoline . This new procedure, which is based on the tin-mediated regioselective acylation of late-stage phosphoglycerol intermediate , overcomes many of the drawbacks of conventional lysophosphatidylation methods and allows introduction of different fatty acyl groups in the penultimate step.

Phospholipidation of TLR7/8-active imidazoquinolines using a tandem phosphoramidite method.

A high-yielding and scalable phosphoramidite procedure was developed for the phospholipidation of TLR7/8-active imidazoquinolines. This method involves the reaction of a 1,2-diacyl- or dialkyl--glycerol or 3-chlolesterylalkanol with 2-cyanoethyl ,,','-tetraisopropylphosphordiamidite in the presence of -tetrazole followed by treatment of the resulting ,'-diisopropylphosphoramidite lipid in situ with 1-imidazoquinolinylalkanols. The resulting phosphite can be purified or directly oxidized with -butyl hydroperoxide.

A structure-activity relationship of non-peptide macrocyclic histone deacetylase inhibitors and their anti-proliferative and anti-inflammatory activities.

Inhibition of the enzymatic activity of histone deacetylase (HDAC) is a promising therapeutic strategy for cancer treatment and several distinct small molecule histone deacetylase inhibitors (HDACi) have been reported. We have previously identified a new class of non-peptide macrocyclic HDACi derived from 14- and 15-membered macrolide skeletons. In these HDACi, the macrocyclic ring is linked to the zinc chelating hydroxamate moiety through a para-substituted aryl-triazole cap group.

Macrolide-peptide conjugates as probes of the path of travel of the nascent peptides through the ribosome.

Despite decades of research on the bacterial ribosome, the ribosomal exit tunnel is still poorly understood. Although it has been suggested that the exit tunnel is simply a convenient route of egress for the nascent chain, specific protein sequences serve to slow the rate of translation, suggesting some degree of interaction between the nascent peptide chain and the exit tunnel. To understand how the ribosome interacts with nascent peptide sequences, we synthesized and characterized a novel class of probe molecules.

Small molecule-gold nanorod conjugates selectively target and induce macrophage cytotoxicity towards breast cancer cells.

Gold nanoparticles are known to activate anti-tumor potential in macrophage immune cells; however, the subsequent effects of these cells on others nearby are poorly understood. A novel gold-nanoparticle conjugate that selectively targets and induces cytotoxic activity of tumor-associated macrophages towards breast cancer cells in co-culture is synthesized. These constructs are promising new tools for studying fundamental biological interactions with nanoscale materials and candidates for emerging macrophage-mediated delivery applications.

Syntheses, properties and cellular studies of metalloisoporphyrins.

b-Bilene hydrochlorides are shown to be improved intermediates for the synthesis of metallo-isoporphyrins in enhanced yields (28% vs. 6%). Several new diamagnetic zinc(II) and a novel paramagnetic copper(II) isoporphyrin salts were also obtained using this approach.

Non-peptide macrocyclic histone deacetylase inhibitors derived from tricyclic ketolide skeleton.

Inhibition of histone deacetylase (HDAC) function is a validated therapeutic strategy for cancer treatment. Of the several structurally distinct small molecule histone deacetylase inhibitors (HDACi) reported, macrocyclic depsipeptides possess the most complex cap groups and have demonstrated excellent HDAC inhibition potency and isoform selectivity. Unfortunately, the development of macrocyclic depsipeptides has been hampered in part because of development problems characteristic of large peptides and the complex reaction schemes required for their synthesis.

Macrocyclic histone deacetylase inhibitors.

Histone deacetylase inhibitors (HDACi) are an emerging class of novel anti-cancer drugs that cause growth arrest, differentiation, and apoptosis of tumor cells. In addition, they have shown promise as anti-parasitic, anti-neurodegenerative, anti-rheumatologic and immunosuppressant agents. To date, several structurally distinct small molecule HDACi have been reported including aryl hydroxamates, benzamides, short-chain fatty acids, electrophilic ketones, and macrocyclic peptides.

Tamoxifen-poly(ethylene glycol)-thiol gold nanoparticle conjugates: enhanced potency and selective delivery for breast cancer treatment.

The breast cancer treatment drug tamoxifen has been widely administered for more than three decades. This small molecule competes with 17beta-estradiol for binding to estrogen receptor, a hormone receptor upregulated in a majority of breast cancers, subsequently initiating programmed cell death. We have synthesized a thiol-PEGylated tamoxifen derivative that can be used to selectively target and deliver plasmonic gold nanoparticles to estrogen receptor positive breast cancer cells with up to 2.

Non-peptide macrocyclic histone deacetylase inhibitors.

Inhibition of histone deacetylase inhibitors (HDACi) hold great promise in cancer therapy because of their demonstrated ability to arrest proliferation of nearly all transformed cell types. Of the several structurally distinct small molecule HDACi reported, macrocyclic depsipeptides have the most complex recognition cap-group moieties and present an excellent opportunity for the modulation of the biological activities of HDACi. Unfortunately, the structure-activity relationship (SAR) studies for this class of compounds have been impaired largely because most macrocyclic HDACi known to date comprise complex peptide macrocycles.

Gold nanoparticles: From nanomedicine to nanosensing.

Because of their photo-optical distinctiveness and biocompatibility, gold nanoparticles (AuNPs) have proven to be powerful tools in various nanomedicinal and nanomedical applications. In this review article, we discuss recent advances in the application of AuNPs in diagnostic imaging, biosensing and binary cancer therapeutic techniques. We also provide an eclectic collection of AuNPs delivery strategies, including assorted classes of delivery vehicles, which are showing great promise in specific targeting of AuNPs to diseased tissues.