Discovery of novel tubulin CBSI (R)-9k from the indanone scaffold for the treatment of colorectal cancer.

In view of the serious adverse reactions and clinical toxicity of first line therapy 5-fluorouracil and lack of small molecule therapeutics in colorectal cancer chemotherapy, a series of natural scaffold-based 3-arylindanone derivatives (9a-q) were designed, synthesized and evaluated as tubulin polymerization inhibitors targeting the colchicine site. The most potent colchicine binding site inhibitor (CBSI), (R)-9k, exhibited 14-38 times more dominant anti-proliferative activity against three colon cancer cell lines than 5-fluorouracil. Particularly, (R)-9k showed higher selectivity against human normal cells compared with 5-fluorouracil and colchicine, and displayed negligible cardiotoxicity through hERG assessment. Furthermore, the binding of (R)-9k to the colchicine site was strongly supported by EBI competition assay and (R)-9k inhibited more tubulin polymerization than colchicine. Besides, the mechanism of action and binding modes of (R)-9k were verified by molecular dynamics simulations and docking. Therefore, (R)-9k could be regarded as a promising CBSI for colorectal cancer therapy.

Discovery of First-in-Class TAK1-MKK3 Protein-Protein Interaction (PPI) Inhibitor (R)-STU104 for the Treatment of Ulcerative Colitis through Modulating TNF-α Production.

Tumor necrosis factor α (TNF-α) has been demonstrated to be a therapeutic target for autoimmune diseases. However, this biological therapy exhibits some inevitable disadvantages, such as risk of infection. Thus, small-molecule alternatives by targeting TNF-α production signaling pathway are still in demand. Herein, we describe the design, synthesis, and structure-activity relationships of 3-aryindanone compounds regarding their modulation of TNF-α production. Among them, (R)-STU104 exhibited the most potent inhibitory activity on TNF-α production, which suppressed the TAK1/MKK3/p38/MnK1/MK2/elF4E signal pathways through binding with MKK3 and disrupting the TAK1 phosphorylating MKK3. As a result, (R)-STU104 demonstrated remarkable dose-effect relationships on both acute and chronic mouse UC models. In addition to its good pharmacokinetic (PK) and safety profile, (R)-STU104 showed better anti-UC efficacy in vivo at 10 mg/kg/d than mesalazine at the dose of 50 mg/kg/d. These results suggested that TAK1-MKK3 interaction inhibitors could be potentially utilized for the treatment of UC.

Discovery of Pyridone-Substituted Triazolopyrimidine Dual A2A/A1 AR Antagonists for the Treatment of Ischemic Stroke.

Ischemic stroke is a complex systemic disease characterized by high morbidity, disability, and mortality. The activation of the presynaptic adenosine A2A and A1 receptors modifies a variety of brain insults from excitotoxicity to stroke. Therefore, the discovery of dual A2A/A1 adenosine receptor (AR)-targeting therapeutic compounds could be a strategy for the treatment of ischemic stroke. Inspired by two clinical phase III drugs, ASP-5854 (dual A2A/A1 AR antagonist) and preladenant (selective A2A AR antagonist), and using the hybrid medicinal strategy, we characterized novel pyridone-substituted triazolopyrimidine scaffolds as dual A2A/A1 AR antagonists. Among them, compound 1a exerted excellent A2A/A1 AR binding affinity (K i = 5.58/24.2 nM), an antagonistic effect (IC50 = 5.72/25.9 nM), and good metabolic stability in human liver microsomes, rat liver microsomes, and dog liver microsomes. Importantly, compound 1a demonstrated a dose-effect relationship in the oxygen-glucose deprivation/reperfusion (OGD/R)-treated HT22 cell model. These findings support the development of dual A2A/A1 AR antagonists as a potential treatment for ischemic stroke.

Exosomes Derived from Hydroquinone-transformed Human Bronchial Epithelial Cells Inhibited Recipient Cell Apoptosis by transferring miR-221.

OBJECTIVE: Although benzene is a confirmed environmental carcinogen, the mechanism of its carcinogenicity remains largely unclear. The suggested oncogene, miR-221, is elevated and plays important roles in various tumors, but its role in benzene-induced carcinogenesis remains unknown. METHODS: In the present study, we constructed hydroquinone (HQ, a representative metabolite of benzene with biological activity)-transformed malignant cell line (16HBE-t) and analyzed the level of miR-221 in it with qRT-PCR. Exosomes from 16HBE-t cells incubated with or without an miR-221 inhibitor were isolated by ultracentrifugation, characterized by transmission electron microscopy and laser scanning confocal microscope, and then transfected into 16HBE cells. The effects of exosomal miR-221 on apoptosis induced by HQ in recipient cells were determined using flow cytometry. RESULTS: The amount of miR-221 in 16HBE-t was significantly increased compared with controls. When recipient cells ingested exosomes derived from 16HBE-t, miR-221 was increased, and apoptosis induced by HQ was inhibited. Blocking miR-221 in 16HBE-t using an inhibitor did not significantly alter miR-221 or apoptosis in recipient cells. CONCLUSION: Exosomal miR-221 secreted by 16HBE-t inhibits apoptosis induced by HQ in normal recipient cells.

Discovery of Novel Indoleamine 2,3-Dioxygenase 1 (IDO1) and Histone Deacetylase 1 (HDAC1) Dual Inhibitors Derived from the Natural Product Saprorthoquinone.

The discovery of IDO1 and HDAC1 dual inhibitors may provide a novel strategy for cancer treatment by taking advantages of both immunotherapeutic and epigenetic drugs. In this paper, saprorthoquinone (1) and 13 of its analogues from Salvia prionitis Hance were investigated for their SAR against IDO1, the results demonstrated the ortho-quinone was a key pharmacophore. Then a series of IDO1 and HDAC dual inhibitors connected by appropriate linkers were designed, synthesized, and evaluated from the hit compound saprorthoquinone (1). Among them, compound 33d showed balanced activity against both IDO1 (IC50 = 0.73 µM) and HDAC1 (IC50 = 0.46 µM). Importantly, the structure of 33d suggested that an ortho-quinone pharmacophore and a N-(2-aminophenyl) amide pharmacophore were necessary for the IDO inhibition and HDAC inhibition respectively. Meanwhile, these two pharmacophore groups should be combined by a pentane linker. Moreover, the binding modes of 33d to the enzyme active site showed that the hydrogen bond with Leu234 of IDO1 appeared to confer increased potency to this class of inhibitors, which may explain the higher activity of 33d. This study provides a new strategy for future IDO1/HDAC dual inhibitors with synergistic antitumor activity started from lead compound 33d.

A Concise Approach to N-Substituted Rhodanines through a Base-Assisted One-Pot Coupling and Cyclization Process.

An efficient approach to obtain functionalized rhodanines was developed through a base-assisted one-pot coupling and continuous cyclization of a primary amine, carbon disulfide, and methyl (2-chloroacetyl)carbamate. This conversion tolerates a broad range of functional groups and can be used to scale the preparation of N-substituted rhodanines in excellent yields.

Novel octapeptide-DTX prodrugs targeting MMP-7 as effective agents for the treatment of colorectal cancer with lower systemic toxicity.

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer death around the world. The current treatments of CRC exhibited high occurrence rate of side effects. Docetaxel (DTX), an important drug widely used in cancer chemotherapy, showed serious toxicity in CRC. Reducing toxicity of DTX could be a feasible and promising way to achieve the new indication of DTX for CRC. In this study, a series of MMP-7 activated octapeptide-DTX/4FDT prodrugs (6a-10a and 6b-10b) were designed and synthesized based on the features of MMP-7 which is highly expressed in CRC and could specially recognize octapeptides with specific sequences. Among them, 9a and 9b, both possessing an octapeptide Gly-Pro-Gln-Gly-Ile-Ala-Met-Gln moiety, were the most potent prodrugs. Compounds 9a and 9b were also tested their release rate in HCT116 cell culture fluids and tumor homogenate along with in vivo anti-CRC activity and systemic toxicity. Since 9a showed better anti-CRC activity and lower systemic toxicity than 9b in CRC tumor bearing mice, it was further evaluated for its acute toxicity, pharmacokinetics and tissue distribution in comparison with its parent drug DTX. These results revealed that 9a possessed good systemic stability, rapid release rate in CRC and reduced systemic toxicity, while retaining similar anti-CRC activity to its parent drug DTX. Thus, 9a, an MMP-7 polypeptide prodrug of DTX, has been identified as a promising candidate for the treatment of CRC.

Novel Mercapto Propionamide Derivatives with Potent New Delhi Metallo-ß-Lactamase-1 Inhibitory Activity and Low Toxicity.

The emergence and worldwide prevalence of New Delhi metallo-ß-lactamase 1 (NDM-1) expressing Gram-negative bacteria with resistance against most ß-lactam antibiotics pose a serious threat to human health. However, no NDM-1 inhibitors are clinically approved at present. Herein, based on the lead compound captopril, a series of compounds were designed, synthesized, and evaluated for NDM-1 inhibitory activities. All designed compounds showed single digit micromolar or submicromolar NDM-1 inhibitory activities, which were much more potent than that of captopril. Among them, compounds 14a and 14m exhibited excellent NDM-1 inhibitory activities, with IC50 values of 0.10 and 0.12 µM, respectively. Further studies demonstrated that compound 14m displayed low cytotoxicity, good water solubility, high metabolic stability, and low acute toxicity in mice. Importantly, compound 14m exhibited potent synergistic antimicrobial activities with Meropenem (MEM) for the treatment of clinically isolated NDM-1-expressing strains.

Zinc-Mediated Decarboxylative Alkylation of Gem-difluoroalkenes.

An efficient and mild zinc-mediated decarboxylative alkylation of gem-difluoroalkenes with N-hydroxyphthalimide (NHP) esters, to give monofluoroalkenes in moderate to excellent yields with high Z-selectivity is reported. The reaction tolerates a broad range of functional groups and can be easily scaled up, which thus may pave the way for its further applications in medicinal chemistry and materials science.

Sulfoxide-Based Enantioselective Nazarov Cyclization: Divergent Syntheses of (+)-Isopaucifloral†F, (+)-Quadrangularin†A, and (+)-Pallidol.

The synthesis of enantiomerically pure 3-aryl substituted indanones is developed using an enantioselective sulfoxide-based Knoevenagel condensation/Nazarov cyclization procedure. After the reductive desulfonation of the methyl para-tolyl sulfoxide-containing chiral auxiliary under mild conditions, selected enantiomerically pure indanone is used for the divergent total syntheses of three resveratrol natural products (+)-isopaucifloral F, (+)-quadrangularin A, and (+)-pallidol.

Discovery of novel sesquistilbene indanone analogues as potent anti-inflammatory agents.

To develop novel anti-inflammatory agents with improved pharmaceutical profiles, twenty-eight novel sesquistilbene indanone analogues were synthesized and evaluated for anti-inflammatory activity using RAW264.7 cells. Among these compounds, compound 11k was found to be one of the most potent analogues in inhibiting NO production in LPS-stimulated RAW264.7 cells. Furthermore, it could also significantly suppress LPS-induced iNOS and COX-2 expression and NO production through TLR4/JNK/NF-κB signaling pathway in a concentration dependent manner.

Differential metabolism of 3FDT and docetaxel in RLMs, rats, and HLMs.

3FDT, an analog of docetaxel with a blocked metabolism at its 3'-N-tert-butyloxyl group with three fluorine atoms, exhibits more potent cytotoxicity than docetaxel both with human cancer cell line SK-OV-3 in vitro and with human non-small cell lung cancer A549 xenografts in vivo. To further develop pharmacodynamically and pharmacokinetically favorable fluorinated docetaxel analogs as anticancer agents, we chose 3FDT as the model compound to identify the metabolites of 3FDT in RLMs, rats, and HLMs and the cytochrome P450 enzymes responsible for the metabolism of 3FDT. Our findings indicated that the major metabolic site switched from the C3' appendage for docetaxel to the taxane ring for 3FDT, and the main metabolizing P450 enzymes switched from CYP3A to CYP3A4 and CYP2E1.