ABSTRACT
Protein Kinase RNA-activated (PKR) inhibition is thought to be relevant for immunology due to the potential to reduce macrophage and dendritic cell responses to bacteria and its signaling downstream of TNFα. PKR is also associated with neuroscience indications such as Alzheimer's disease due to its activation by the double stranded DNA (dsDNA) virus HSV1, a virus suggested to be important in the development of AD. Studies exploring the mechanistic role of PKR with existing tool molecules such as the tricyclic oxindole C16 are clouded by the poor selectivity profile of this ATP-competitive, Type I kinase inhibitor. Type II kinase leads such as the benzothiophene or pyrazolopyrimidine scaffolds from literature are equally poor in their selectivity profiles. As such, it became necessary to identify more potent and selective chemical matter to better understand PKR biology. A dual approach was taken. The first step of the strategy included virtual screening of the AbbVie compound collection. A combination of pharmacophore-based and GPU shape-based screening was pursued to identify selective chemical matter from promiscuous leads. The second step of the strategy followed traditional compound design. This step initiated from a literature lead with PKR cross reactivity. Combined, the two parallel efforts led to identification of more selective leads for investigation of PKR biology.
Subject(s)
Protein Kinase Inhibitors , Humans , Alzheimer Disease/metabolism , Macrophages/drug effects , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Drug Discovery/methodsABSTRACT
A novel structural class of antibacterials, 2-(1H-indol-3-yl)quinolines, effective against methicillin-resistant Staphylococcus aureus (MRSA), was discovered from a combinatorial library. A structure-activity relationship (SAR) study was conducted to determine the pharmacophore and increase the potency of these compounds. Compounds were prepared that had minimum inhibitory concentrations (MICs) < 1.0 microg/mL against MRSA and retained activity against two strains of glycopeptide intermediate-resistant S. aureus (GISA).
Subject(s)
Anti-Bacterial Agents/pharmacology , Indoles/pharmacology , Methicillin Resistance , Quinolines/pharmacology , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/chemistry , Combinatorial Chemistry Techniques , Indoles/chemistry , Microbial Sensitivity Tests , Quinolines/chemistry , Structure-Activity RelationshipABSTRACT
N-Acyl analogues 8, 9, and 12-26 of butitaxel (3) were prepared in one or two steps from amines 5 and 6 through Schotten-Baumann acylation. Seventeen novel analogues, consisting of aliphatic carbamates, alicyclic amides, and heteroaromatic amides, were synthesized. They were evaluated for their in vitro ability to stimulate the formation of microtubules, their cytotoxicity toward B16 melanoma cells, and their solubility in water. The most potent analogue found in this study was N-debenzoyl-N-(2-thenoyl)butitaxel (20), possessing ca. 2-fold better tubulin assembly properties and cytotoxic activity against B16 melanoma cells than paclitaxel. Compound 20 was ca. 25 times more water soluble than paclitaxel.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Paclitaxel/analogs & derivatives , Taxoids , Animals , Drug Screening Assays, Antitumor , Melanoma, Experimental/drug therapy , Mice , Microtubules/drug effects , Paclitaxel/chemical synthesis , Paclitaxel/chemistry , Paclitaxel/pharmacology , Solubility , Structure-Activity RelationshipABSTRACT
3'-(tert-Butyl) 3'-dephenyl analogs of paclitaxel were synthesized from 10-deacetylbaccatin III and oxazolidinecarboxylic acid 7 followed by acylation of intermediate amines 10 and 11. Oxazolidinecarboxylic acid 7 was prepared in five steps and in good overall yield from L-tert-leucine. Twelve analogs were synthesized and evaluated for their in vitro ability to stimulate the formation of microtubules and for their cytotoxicity against B16 melanoma cells. Amide, carbamate, urea, and thiourea congeners were prepared. The most potent derivatives found in this study are the docetaxel analog 13, the N-[(tert-amyloxy)carbonyl] analog 17, and the 3'-phenylurea and 3'-tert-butylurea derivatives 20 and 23. Six of these analogs were shown to be ca. 90 times more soluble in water than paclitaxel and ca. 4-5 times more water-soluble than docetaxel.
