A GLUT1 inhibitor-based fluorogenic probe for Warburg effect-targeted drug screening and diagnostic imaging of hyperglycolytic cancers.

Increased expression of glucose transporters, especially GLUT1 has been proven to be involved in the Warburg effect. Therefore, GLUT1-targeted oncological approaches are being successfully employed for clinical tumor diagnostic imaging (e.g. the 18F-FDG/PET), drug delivery and novel anticancer drug development. Despite the long history of the Warburg effect-targeted cancer diagnosis, other than antibody labeling, there have been no imaging tools developed for direct detection of the GLUT1 expression. Herein, we report the new strategy of using a non-antibody GLUT1 binding probe for Warburg effect-based tumor detection and diagnostic imaging. By specifically inhibits the transport function of GLUT1, the newly designed fluorescent probe, CUM-5, was found to be a useful tool not only for sensitive GLUT1-mediated cancer cell detection, but also for cell-based high-throughput GLUT inhibitor screening. In in vivo studies, CUM-5 shows clear advantages including desirable tumor-to-normal tissue contrast and excellent tumor selectivity (Tm/Bkg and Tm/Torg), as well as high fluorescence stability (long response time) and ideal physiological biocompatibility. In particular, the GLUT1 inhibitor probe offers the potential use for glycolysis-based diagnostic imaging in triple-negative breast cancer which is claimed to have unsatisfactory results with FDG/PET diagnosis, thus remaining a highly metastatic and lethal disease with a need for sensitive and precise identification.

N-(Sulfamoylbenzoyl)-L-proline Derivatives as Potential Non-ß-lactam ESBL Inhibitors: Structure-Based Lead Identification, Medicinal Chemistry and Synergistic Antibacterial Activities.

BACKGROUND: There is an urgent need to develop novel inhibitors against clinically widespread extended-spectrum ß-lactamases (ESBLs) to meet the challenges of the ever-evolving threat of antibiotic resistances. Most existing ESBL inhibitors sharing a common chemical feature of ß-lactam ring in their molecule, this structural characteristic makes them intrinsically susceptible to enzymatic breakdown by the resistance mechanisms employed by the bacteria. OBJECTIVE: The aim of this study was to screen and discover novel lead compounds by using Lproline as initial scaffold to create a "non-sulfur, non-ß-lactam" new chemotypes for potential ESBL inhibitors. METHODS: Structure-based molecular docking and virtual screening were employed in the novel inhibitor generation process for lead compound screening and SAR analysis. Evaluation of the ESBL inhibitory activity of the lead compounds was performed in combination with three of the most susceptible antibiotics: ceftazidime, meropenem and ampicillin, against thirteen ESBL enzymes including four new CTX-M harboring strains and four KPC-2 producing species. RESULTS: L-proline derived (S)-1-(2-sulfamoylbenzoyl)pyrrolidine-2-carboxylic acid (compound 6) as a "non-sulfur, non-ß-lactam" and the most potential ESBL inhibitor was identified. Compound 6 possesses ideal anti-resistance activities by reducing MICs of ceftazidime, meropenem and ampicillin by 16-133, 32-133 and 67-267 fold respectiveily. The inhibitory mechanism of 6 with CTX-M, KPC-2 and penicillinase were proposed and probed with molecular docking analysis. CONCLUSION: Given that the simple proline derivative but promising synergistic antibacterial properties of compound 6 augers well for further investigations into its in vivo efficacy.

Discovery of Nonpeptide, Reversible HER1/HER2 Dual-Targeting Small-Molecule Inhibitors as Near-Infrared Fluorescent Probes for Efficient Tumor Detection, Diagnostic Imaging, and Drug Screening.

The abnormal expression of epidermal growth factor receptors HER1(EGFR) and HER2 is strongly associated with cancer invasion, metastasis, and angiogenesis. Their molecular detection is mainly executed using genetically encoded or antibody-based diagnostic tracers, but no dual-targeting small-molecule bioprobe has been achieved. Here, we report the novel small-molecule fluorescent probes Cy3-AFTN and Cy5-AFTN as potent dual-targeting inhibitors for efficient detection of HER1/HER2 expression in cancer cells and in vivo tumor diagnostic imaging. Unlike the irreversible HER1/HER2 inhibitors, Cy3-AFTN and Cy5-AFTN were designed as reversible/noncovalent probes based on the clinical drug afatinib, by making the molecule structurally impossible for receptor-mediated Michael additions. The synthesized probes were validated with live cell fluorescence imaging, flow cytometry and confocal-mediated competitive binding inhibition, molecular docking study, and in vivo xenograft tumor detection. The probes are competitively replaceable by other HER1/HER2 inhibitors; thus, they are potentially useful in fluorometric high-throughput screening for drug discovery.

The genus Polygonatum: A review of ethnopharmacology, phytochemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Polygonatum (Asparagaceae) comprises 71 species distributed throughout the temperate Northern Hemisphere. The medicinal plants of Polygonatum have been traditionally used as tonics in China, India, Pakistan, Iran and Japan, and have been demonstrated to be highly effective in clinical practice for treating age-related diseases, diabetes, lung diseases, fatigue, feebleness and indigestion. AIM OF THE REVIEW: This paper aims to provide the links among traditional uses, chemical constituents, pharmacological effects and toxicity to support their therapeutic potential and uncover opportunities for future research. MATERIALS AND METHODS: The relevant information on the genus Polygonatum was gathered from scientific databases (Google Scholar, Web of Science, SciFinder, ScienceDirect, ACS Publications, PubMed, Wiley Online Library, CNKI). Information was also obtained from online databases, books, Ph.D. dissertations and M.Sc. theses. The literature cited in this review dates from 1917 to June 2017. RESULTS: At least 37 species and 1 variety of Polygonatum plants have been used as traditional medicine and functional food. The major chemical constituents of Polygonatum plants are steroidal saponins, triterpenoid saponins, homoisoflavanones, polysaccharides and lectins. A putative biosynthetic pathway of steroidal saponins and triterpenoid saponins has been established based on the compounds isolated from Polygonatum plants. The crude extracts and certain pure compounds from Polygonatum plants have shown a wide range of pharmacological effects such as anti-aging, anti-diabetic, anti-fatigue, and anticancer effects. The rhizomes of Polygonatum plants have a low degree of toxicity after processing. CONCLUSIONS: Based on this review, some traditional uses of Polygonatum species have been confirmed by pharmacological studies, such as its anti-osteoporosis, neuroprotective, immunomodulatory, anti-diabetic and anti-fatigue effects. Most of the pharmacological effects of this genus can be attributed to its polysaccharides, saponins and lectins. However, to clarify the chemical differences that lead to the different traditional uses between "Huangjing" (derived from P. sibiricum, P. kingianum, P. cyrtonema) and "Yuzhu" (derived from P. odoratum), a systematic comparison of the small molecule compositions and polysaccharides of these four species is needed. In addition to these four species, other locally used medicinal Polygonatum species should be the subject of research, and the chemical and pharmacological relationships of these species should be investigated to expand the medicinal resources and standardize the use of Polygonatum species.

3D-QSAR study of corticotropin-releasing factor 1 antagonists and pharmacophore-based drug design.

Corticotropin-releasing factor (CRF) is a neuropeptide that falls into the broad spectrum of having neurotransmitter/neurohormonal/neuromodulator activities. The design and synthesis of low molecular weight non-peptide antagonists for the CRF receptors is a very important area of research as they can be employed in the treatment of a wide variety of disorders. To investigate the ligand-receptor binding mode and design novel CRF1 antagonists, both quantitative and qualitative 3D-QSAR analysis have been performed on a data set of CRF(1) antagonists by using HypoGen and HipHopRefine programs of Catalyst software. The training set of HypoGen study included twenty-five structurally diverse CRF(1) antagonists with Ki values ranging from 0.5 nM to 10 microM. The common feature-based 3D-QSAR study used eight highly potent CRF(1) antagonists and four poor antagonistic ligands to generate 3D-pharmacophore models with excluded volumes. The obtained 3D-pharmacophore models from each study served as queries for virtual screening with a 'focused compound library' for novel CRF(1) antagonist development. Pharmacophore models obtained for antagonist binding are useful for CRF related chemical biology and drug design. Strategies and methods employed in this paper are simple and practical for medicinal chemists in drug R&D.

Molecular docking study of A(3) adenosine receptor antagonists and pharmacophore-based drug design.

Adenosine is known to act as a neuromodulator by suppressing synaptic transmission in the central and peripheral nervous system. A(3) adenosine receptor (A(3)AR) antagonists were recently considered as potential drugs for the treatment of cardiac ischemia and inflammation diseases. To better understand the chemical features responsible for the recognition mechanism and the receptor-ligand interaction, we have performed the molecular simulation study combined with a virtual library screening process to develop novel A(3)AR antagonists. A series of A(3)AR selective antagonists, including triazolopurines, imidazopurines, pyrrolopurines, and quinazolines were employed to dock into the A(3)AR binding site via AUTODOCK software. The putative binding mode for each compound was proposed. Three main hydrophobic pockets, one hydrogen bonding with Asn250, and one pi-pi interaction with Phe168 for all antagonists were identified. The most favorable binding conformations served as the templates for pharmacophore modeling with Catalyst 4.11 and a virtually generated library have been screened for novel antagonist development.

3D-pharmacophore model for RXR(gamma) agonists.

Three-dimensional pharmacophore models were generated for retinoid X receptor (RXR(gamma)) agonists using quantitative approach (CATALYST HypoRefine). One optimal pharmacophore model for selective RXR(gamma) agonists was determined through careful validation processes. The best quantitative model (Hypo-1) had five features and five excluded volumes: three hydrophobic aliphatic groups (HAL1, HAL2, and HAL3), one hydrophobic aromatic ring (HAR), and one hydrogen bond acceptor (HBA). The model was validated using a wide range of test molecules. It could predict agonist activity and identify highly potent molecules. The present results are valuable to discover and develop specific RXR(gamma) agonists with desired biological activities.