Discovery, structure-activity relationship studies, and anti-nociceptive effects of N-(1,2,3,4-tetrahydro-1-isoquinolinylmethyl)benzamides as novel opioid receptor agonists.

µ-Opioid receptor (MOR) agonists are analgesics used clinically for the treatment of moderate to severe pain, but their use is associated with severe adverse effects such as respiratory depression, constipation, tolerance, dependence, and rewarding effects. In this study, we identified N-({2-[(4-bromo-2-trifluoromethoxyphenyl)sulfonyl]-1,2,3,4-tetrahydro-1-isoquinolinyl}methyl)cyclohexanecarboxamide (1) as a novel opioid receptor agonist by high-throughput screening. Structural modifications made to 1 to improve potency and blood-brain-barrier (BBB) penetration resulted in compounds 45 and 46. Compound 45 was a potent MOR/KOR (κ-opioid receptor) agonist, and compound 46 was a potent MOR and medium KOR agonist. Both 45 and 46 demonstrated a significant anti-nociceptive effect in a tail-flick test performed in wild type (WT) B6 mice. The ED50 value of 46 was 1.059 mg/kg, and the brain concentrations of 45 and 46 were 7424 and 11696 ng/g, respectively. Accordingly, compounds 45 and 46 are proposed for lead optimization and in vivo disease-related pain studies.

BPR0C305, an orally active microtubule-disrupting anticancer agent.

BPR0C305 is a novel N-substituted indolyl glyoxylamide previously reported with in-vitro cytotoxic activity against a panel of human cancer cells including P-gp-expressing multiple drug-resistant cell sublines. The present study further examined the underlying molecular mechanism of anticancer action and evaluated the in-vivo antitumor activities of BPR0C305. BPR0C305 is a novel synthetic small indole derivative that demonstrates in-vitro activities against human cancer cell growth by inhibiting tubulin polymerization, disrupting cellular microtubule assembly, and causing cell cycle arrest at the G2/M phase. It is also orally active against leukemia and solid tumor growths in mouse models. Findings of these pharmacological and pharmacokinetic studies suggest that BPR0C305 is a promising lead compound for further preclinical developments.

Quantitative analysis of oligosaccharides derived from sulfated glycosaminoglycans by nanodiamond-based affinity purification and matrix-assisted laser desorption/ionization mass spectrometry.

Degraded fragments of sulfated glycosaminoglycans (GAGs) are key reporters for profiling the burden of mucopolysaccharidosis (MPS) disease at baseline and during therapy. Here, we present a high-throughput assay, which combines microwave-assisted degradation, solid-phase affinity purification, and matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), for quantitative analysis of sulfated oligosaccharides in biological samples. First, sulfated oligosaccharides such as chondroitin-4-sulfate (CS) were efficiently isolated from highly diluted solutions or spiked artificial cerebrospinal fluid (aCSF) using polyarginine-coated nanodiamonds (PA-coated NDs) as affinity sorbents. Next, they were degraded to disaccharides through microwave-assisted methanolysis or enzymatic digestion for subsequent MALDI-TOF MS analysis. The reaction times for GAG depolymerization were significantly reduced from a few hours to less than 7 min under the microwave irradiation. Deuterium-labeled internal standards were then mixed with the CS-derived disaccharides for quantitative analysis by MALDI-TOF MS using the N-(1-naphthyl) ethylenediamine dihydrochloride (NEDC) matrix. The new assay is facile, specific (with distinct chlorine-isotope trait markers), sensitive (with a detection limit of ~70 pg), and potentially useful for clinical diagnosis of MPS.