In Vitro and In Vivo Antibacterial Activities of a Novel Quinolone Compound, OPS-2071, against Clostridioides difficile.

OPS-2071 is a novel quinolone antibacterial agent characterized by low oral absorption that reduces the risk of adverse events typical of fluoroquinolone class antibiotics. The in vitro and in vivo antibacterial activities of OPS-2071 against Clostridioides difficile were evaluated in comparison to vancomycin and fidaxomicin. OPS-2071 exhibited potent antibacterial activity against 54 clinically isolated C. difficile strains with a MIC of 0.125 µg/ml (MIC50) and 0.5 µg/ml (MIC90), making it more active than vancomycin on a concentration basis (MIC50, 2 µg/ml; MIC90, 4 µg/ml) and comparable to fidaxomicin (MIC50, 0.063 µg/ml; MIC90, 8 µg/ml). OPS-2071 showed equally potent antibacterial activity against both hypervirulent and nonhypervirulent strains, while a significant difference in susceptibility to fidaxomicin was observed. Spontaneous resistance to OPS-2071 and vancomycin was not observed; however, resistance to fidaxomicin was observed at 4× MIC. The mutant prevention concentration of OPS-2071 was 16-fold lower than those of fidaxomicin and vancomycin, and the postantibiotic effect of OPS-2071 was longer than those of fidaxomicin and vancomycin. Also, OPS-2071 showed low systemic exposure, with OPS-2071 having 2.9% oral bioavailability at 1 mg/kg in rats. Furthermore, OPS-2071 showed significant in vivo efficacy at 0.0313 mg/kg/day (50% effective doses), 39.0-fold and 52.1-fold lower than those of vancomycin and fidaxomicin, respectively, in a hamster model of C. difficile infection. OPS-2071 has the potential to become a new therapeutic option for treating C. difficile infection.

Meta-analysis of transarterial chemoembolization combined with cryoablation vs transarterial chemoembolization alone for ≥ 5 cm hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) ranks sixth globally in cancer incidence and third in mortality rates. Unfortunately, over 70% of HCC patients forego the opportunity for curative surgery or liver transplantation due to inadequate physical examinations, poor physical condition, and limited organ availability upon diagnosis. Clinical guidelines endorse transarterial chemoembolization (TACE) as the frontline treatment for intermediate to advanced-stage HCC. Cryoablation (CRA) is an emerging local ablative therapy increasingly used in HCC management. Recent studies suggest that combining CRA with TACE offers complementary and synergistic effects, potentially improving long-term survival rates. However, the superiority of combined TACE + CRA therapy over TACE alone for HCC lesions equal to or exceeding 5 cm requires further investigation. AIM: To compare the efficacy and safety of TACE combined with CRA vs TACE alone in the treatment of HCC with a diameter of ≥ 5 cm. METHODS: PubMed, EMBASE, Cochrane Library, CNKI, Wanfang, and VIP databases were searched to retrieve all relevant studies on TACE and CRA up to July 2022. Meta-analysis was performed using RevMan 5.3 software. RESULTS: After screening according to the inclusion and exclusion criteria, 6 articles were included, including 2 randomized controlled trials and 4 nonrandomized controlled trials, with a total of 575 patients included in the meta-analysis. The results showed that the objective response rate [odds ratio (OR) = 2.56, 95% confidence interval (CI):1.66-3.96, P < 0.0001), disease control rate (OR = 3.03, 95%CI: 1.88-4.89, P < 0.00001), 1-year survival rate (OR = 3.79, 95%CI: 2.50-5.76, P < 0.00001), 2-year survival rate (OR = 2.34, 95%CI: 1.43-3.85, P = 0.0008), and 3-year survival rate (OR = 3.34, 95%CI: 1.61-6.94, P = 0.001) were all superior to those of the control group; the postoperative decrease in alpha-fetoprotein value (OR = 295.53, 95%CI: 250.22-340.85, P < 0.0001), the postoperative increase in CD4 value (OR = 10.59, 95%CI: 8.78-12.40, P < 0.00001), and the postoperative decrease in CD8 value (OR = 6.47, 95%CI: 4.44-8.50, P < 0.00001) were also significantly higher than those in the TACE-alone treatment group. CONCLUSION: Compared with TACE-alone treatment, TACE + CRA combined treatment not only improves the immune function of HCC patients with a diameter of ≥ 5 cm, but also enhances the therapeutic efficacy and long-term survival rate, without increasing the risk of complications. Therefore, TACE + CRA combined treatment may be a more recommended treatment for patients with HCC with a diameter of ≥ 5 cm.

Combination of virtual screening and high throughput gene profiling for identification of novel liver X receptor modulators.

We conducted virtual docking studies using GLIDE with modified LXRbeta ligand-binding domain (LBD) on internal compound collection followed by the gene profiling with ArrayPlate mRNA assay. A total of 69 compounds were found to upregulate LXRalpha and certain LXR regulated genes from 1308 compounds selected by virtual screen (hit rate: 5.3%). Compound 4 was shown to significantly induce the expression of LXR target genes such as ABCA1, ABCG1, APOE, SCD-1, and SREBP-1c in THP-1 differentiated macrophages. In vitro binding assay confirmed that 4 binds to both LXRalpha and LXRbeta directly and recruits coactivator peptide SRC-1. It functions as a full LXR agonist in stimulating cholesterol efflux in THP-1 differentiated macrophages and induces lipogenesis in HepG2 cells. This study demonstrates that the combination of virtual screen and high throughput gene profiling is an efficient approach for rapid identification of novel LXR modulators.

Discovery of potent and orally available malonyl-CoA decarboxylase inhibitors as cardioprotective agents.

Discovery of 5-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-4,5-dihydroisoxazole-3-carboxamides as a new class of malonyl-coenzyme A decarboxylase (MCD) inhibitors is described. tert-Butyl 3-(5-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-4,5-dihydroisoxazole-3-carboxamido)butanoate (5, CBM-301940) exhibited excellent potency and in vivo PK/ADME properties. It is the most powerful stimulant of glucose oxidation reported to date in isolated working rat hearts. Compound 5 improved the cardiac efficiency and function in a rat heart global ischemia/reperfusion model, suggesting MCD inhibitors may be useful for the treatment of ischemic heart diseases.

Synthesis and structure-activity relationship of small-molecule malonyl coenzyme A decarboxylase inhibitors.

The discovery and structure-activity relationship of first-generation small-molecule malonyl-CoA decarboxylase (MCD; CoA = coenzyme A) inhibitors are reported. We demonstrated that MCD inhibitors increased malonyl-CoA concentration in the isolated working rat hearts. Malonyl-CoA is a potent, endogenous, and allosteric inhibitor of carnitine palmitoyltransferase-I (CPT-I), a key enzyme for mitochondrial fatty acid oxidation. As a result of the increase in malonyl-CoA levels, fatty acid oxidation rates were decreased and the glucose oxidation rates were significantly increased. Demonstration of in vivo efficacy of methyl 5-(N-(4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)phenyl)morpholine-4-carboxamido)pentanoate (6u) in a pig ischemia model indicated that MCD inhibitors may be useful for treating ischemic heart diseases.

Malonyl coenzyme a decarboxylase inhibition protects the ischemic heart by inhibiting fatty acid oxidation and stimulating glucose oxidation.

Abnormally high rates of fatty acid oxidation and low rates of glucose oxidation are important contributors to the severity of ischemic heart disease. Malonyl coenzyme A (CoA) regulates fatty acid oxidation by inhibiting mitochondrial uptake of fatty acids. Malonyl CoA decarboxylase (MCD) is involved in the decarboxylation of malonyl CoA to acetyl CoA. Therefore, inhibition of MCD may decrease fatty acid oxidation and protect the ischemic heart, secondary to increasing malonyl CoA levels. Ex vivo working rat hearts aerobically perfused in the presence of newly developed MCD inhibitors showed an increase in malonyl CoA levels, which was accompanied by both a significant decrease in fatty acid oxidation rates and an increase in glucose oxidation rates compared with controls. Using a model of demand-induced ischemia in pigs, MCD inhibition significantly increased glucose oxidation rates and reduced lactate production compared with vehicle-treated hearts, which was accompanied by a significant increase in cardiac work compared with controls. In a more severe rat heart global ischemia/reperfusion model, glucose oxidation was significantly increased and cardiac function was significantly improved during reperfusion in hearts treated with the MCD inhibitor compared with controls. Together, our data show that MCD inhibitors, which increase myocardial malonyl CoA levels, decrease fatty acid oxidation and accelerate glucose oxidation in both ex vivo rat hearts and in vivo pig hearts. This switch in energy substrate preference improves cardiac function during and after ischemia, suggesting that pharmacological inhibition of MCD may be a novel approach to treating ischemic heart disease.

Two-dimensional turbulent flow chromatography coupled on-line to liquid chromatography-mass spectrometry for solution-based ligand screening against multiple proteins.

We present herein a novel bioseparation/chemical analysis strategy for protein-ligand screening and affinity ranking in compound mixtures, designed to increase screening rates and improve sensitivity and ruggedness in performance. The strategy is carried out by combining on-line two-dimensional turbulent flow chromatography (2D-TFC) with liquid chromatography-mass spectrometry (LC-MS), and accomplished through the following steps: (1) a reversed-phase TFC stage to separate the protein/ligand complex from the unbound free molecules, (2) an on-line dissociation process to release the bound ligands from the complexes, and (3) a second mixed-mode cation-exchange/reversed-phase TFC stage to trap the bound ligands and to remove the proteins and salts, followed by LC-MS analysis for identification and determination of the binding affinities. The technique can implement an ultra-fast isolation of protein/ligand complex with the retention time of a complex peak in about 5s, and on-line prepare the "clean" sample to be directly compatible with the LC-MS analysis. The improvement in performance of this 2D-TFC/LC-MS approach over the conventional approach has been demonstrated by determining affinity-selected ligands of the target proteins acetylcholinesterase and butyrylcholinesterase from a small library with known binding affinities and a steroidal alkaloid library composed of structurally similar compounds. Our results show that 2D-TFC/LC-MS is a generic and efficient tool for high-throughput screening of ligands with low-to-high binding affinities, and structure-activity relationship evaluation.

CCR1 antagonists.

CCR1 (CC Chemokine receptor 1) is a widely studied G protein-coupled receptor target expressed on multiple types of leukocytes. It is implicated in initiating and exacerbating inflammatory conditions and thus is viewed as a good target for autoimmune and inflammatory therapeutic applications. Numerous CCR1 antagonists have been reported. Although some early CCR1 antagonists lacked the species cross reactivity that made in vivo animal model study difficult, efforts have been made to improve the compound potency in rodents. Recent identification of new and improved CCR1 antagonists has resulted in promising, in vivo efficacy in a variety of animal models of disease. While several early compounds have been withdrawn from clinical trials due to lack of efficacy, work continues to evaluate CCR1 antagonists in preclinical and clinical settings.

Hamigerols A and B, unprecedented polysulfate sterol dimers from the Mediterranean sponge Hamigera hamigera.

Two novel polysulfate sterol dimers, hamigerols A (1) and B (2), have been isolated from the Mediterranean sponge Hamigera hamigera. Their structures and stereochemistry have been assigned from the analysis of spectroscopic data.

Novel trifluoroacetophenone derivatives as malonyl-CoA decarboxylase inhibitors.

A series of trifluoroacetophenone derivatives were prepared and evaluated as malonyl-CoA decarboxylase (MCD) inhibitors. Some of the 'reverse amide' analogs were found to be potent inhibitors of MCD enzyme activity. The trifluoroacetyl group may interact with the MCD active site as the hydrate in a similar fashion to the hexafluoroisopropanol analogs reported previously. Adding electron-withdrawing groups to the phenyl ring stabilizes the hydrated species and enhances this interaction.

Myriaporones 1-4, cytotoxic metabolites from the Mediterranean bryozoan Myriapora truncata.

Four novel polyketide-derived metabolites, myriaporones 1, 2, 3, and 4, have been isolated from the Mediterranean bryozoan Myriapora truncata. Their structures and stereochemistry have been assigned from the analysis of spectroscopic data. The inseparable equilibrium mixture of myriaporones 3 and 4 showed 88% inhibition of L1210 murine leukemia cells at 0.2 microg/mL.

2-Aryl-N-acyl indole derivatives as liver X receptor (LXR) agonists.

Structure-activity relationship studies on a series of Boc-indole derivatives as LXR agonists are described. Compound 1 was identified as an LXR agonist through structure-based virtual screening followed by high-throughput gene profiling. Replacement of the indan linker portion in 1 with an open-chain linker resulted in compounds with similar or improved in vitro potency and cellular functional activity. The Boc group at the N-1 position of the indole moiety can be replaced with a benzoyl group. The SAR studies led to the identification of compound 8, a potent LXRbeta agonist with an EC50 of 12 nM in the cofactor recruitment assay.

Synthesis and structure-activity relationship of 4-(2-aryl-cyclopropylamino)-quinoline-3-carbonitriles as EGFR tyrosine kinase inhibitors.

Synthesis and structure-activity relationship of a series of 4-(2-aryl-cyclopropylamino)-quinoline-3-carbonitrile derivatives as EGFR inhibitors is described. Compounds 29 and 30 showed potent in vitro inhibitory activity in the enzymatic assay as well as in the functional cellular assay. They are moderately selective against other types of tyrosine kinases.

Discovery and structure-activity relationship studies of indole derivatives as liver X receptor (LXR) agonists.

A structurally novel liver X receptor (LXR) agonist (1) was identified from internal compound collection utilizing the combination of structure-based virtual screening and high-throughput gene profiling. Compound 1 increased ABCA1 gene expression by eightfold and SREBP1c by threefold in differentiated THP-1 macrophage cell lines. Confirmation of its agonistic activity against LXR was obtained in the co-factor recruitment and reporter transactivation assays. Structure-activity relationship studies on compound 1 are described.

Design and synthesis of heterocyclic malonyl-CoA decarboxylase inhibitors.

We have previously reported the discovery of small molecule inhibitors of malonyl-CoA decarboxylase (MCD) as novel metabolic modulators, which inhibited fatty acid oxidation and consequently increased the glucose oxidation rates in the isolated working rat hearts. MCD inhibitors were also shown to improve cardiac efficiency in rat and pig demand-induced ischemic models through the mechanism-based modulation of energy metabolism. Herein, we describe the design and synthesis of a series of novel heterocyclic MCD inhibitors with a preference for substituted imidazole and isoxazole.

Heteroaryl substituted bis-trifluoromethyl carbinols as malonyl-CoA decarboxylase inhibitors.

A series of heteroaryl-substituted bis-trifluoromethyl carbinols were prepared and evaluated as malonyl-CoA decarboxylase (MCD) inhibitors. Some thiazole-based derivatives showed potent in vitro MCD inhibitory activities and significantly increased glucose oxidation rates in isolated working rat hearts.

Novel chromene derivatives as TNF-alpha inhibitors.

A novel series of chromene-based TNF-alpha inhibitors is described. These chromene derivatives inhibit bacterial lipopolysaccharide (LPS) stimulated production of TNF-alpha from human peripheral blood mononuclear cells (PBMC). Additionally, these compounds inhibit NF-kB mediated transcription activation.

Discovery and structure-activity relationship of coumarin derivatives as TNF-alpha inhibitors.

The discovery and structure-activity relationship of a novel series of coumarin-based TNF-alpha inhibitors is described. Starting from the initial lead 1a, various derivatives were prepared surrounding the coumarin core structure to optimize the in vitro inhibitory activity of TNF-alpha production by human peripheral blood mononuclear cells (hPBMC), stimulated by bacterial lipopolysaccharide (LPS). Selected compounds also demonstrated in vivo inhibition of TNF-alpha production in rats.