MedChemComm最新文献

Accumulating evidence suggests that the root of drug chemoresistance in ovarian cancer is tightly associated with subpopulations of cancer stem cells (CSCs), whose activation is largely associated with signal transducer and activator of transcription 3 (STAT3) signaling. Recently, celastrol has shown a significant anti-cancer effect on ovarian cancer, but its clinical translation is very challenging due to its oral bioavailability and high organ toxicity. In this study, a celastrol derivative (Cel-N) was synthesized to augment the overall efficacy, and its underlying mechanisms were also explored. Different ovarian cancer cells, SKOV3 and A2780, were used to evaluate and compare the anticancer effects. Cel-N displayed potent activities against all the tested ovarian cancer cells, with the lowest IC₅₀ value of 0.14–0.25 μM. Further studies showed that Cel-N effectively suppressed the colony formation and sphere formation ability, decreased the percentage of CD44⁺CD24⁻ and ALDH⁺ cells, and induced ROS production. Furthermore, western blot analysis indicated that Cel-N significantly inhibited both Tyr705 and Ser727 phosphorylation and reduced the protein expression of STAT3. In addition, Cel-N could dramatically induce apoptosis and cell cycle arrest, and inhibit migration and invasion. Importantly, Cel-N showed a potent antitumor efficacy with no or limited systemic toxicity in mice xenograft models. The anticancer effect of Cel-N is stronger than celastrol. Cel-N attenuates cancer cell stemness, inhibits the STAT3 pathway, and exerts anti-ovarian cancer effects in cell and mouse models. Our data support that Cel-N is a potent drug candidate for ovarian cancer.

Pharmacologically active small organic molecules derived from natural resources are prominent drug candidates due to their inherent structural diversity. Herein, we explored one such bioactive molecule, niloticin, which is a tirucallane-type triterpenoid isolated from the stem barks of Aphanamixis polystachya (Wall.) Parker. After initial screening with other isolated compounds from the same plant, niloticin demonstrated selective cytotoxicity against cervical cancer cells (HeLa) with an IC₅₀ value of 11.64 μM. Whereas the compound exhibited minimal cytotoxicity in normal epithelial cell line MCF-10A, with an IC₅₀ value of 83.31 μM. Subsequently, in silico molecular docking studies of niloticin based on key apoptotic proteins such as p53, Fas, FasL, and TNF β revealed striking binding affinity, reflecting docking scores of −7.2, −7.1, −6.8, and −7.2. Thus, the binding stability was evaluated through molecular dynamic simulation. In a downstream process, the apoptotic capability of niloticin was effectively validated through in vitro fluorimetric assays, encompassing nuclear fragmentation. Additionally, an insightful approach involving surface-enhanced Raman spectroscopy (SERS) re-establishes the occurrence of DNA cleavage during cellular apoptosis. Furthermore, niloticin was observed to induce apoptosis through both intrinsic and extrinsic pathways. This was evidenced by the upregulation of upstream regulatory molecules such as CD40 and TNF, which facilitate the activation of caspase 8. Concurrently, niloticin-induced p53 activation augmented the expression of proapoptotic proteins Bax and Bcl-2 and downregulation of IAPs, leading to the release of cytochrome C and subsequent activation of caspase 9. Therefore, the reflection of mitochondrial-mediated apoptosis is in good agreement with molecular docking studies. Furthermore, the anti-metastatic potential was evidenced by wound area closure and Ki67 expression patterns. This pivotal in vitro assessment confirms the possibility of niloticin being a potent anti-cancer drug candidate, and to the best of our knowledge, this is the first comprehensive anticancer assessment of niloticin in HeLa cells.

A series of 14 conjugates of 2α,3β,23-triacetyl-madecassic acid and silybin were designed and synthesized. The madecassic acid unit was linked to silybin either directly at position C-7 or C-3; or through an amino acid linker (glycine, β-alanine, or 11-aminoundecanoic acid) at position C-3. The conjugates were tested in vitro for their cytotoxic effect on HepG2 cells using the MTT assay. The results confirmed that the conjugated compounds demonstrated a stronger cytotoxic effect compared to the parent compounds. Of these compounds, the most promising conjugate, compound 8, was evaluated for cytotoxic activity in the additional Hep3B, Huh7, and Huh7R human hepatocellular carcinoma cell lines and also for cell cycle changes and induction of apoptosis in HepG2 cells. This compound caused a rapid and significant induction of caspase 3 activity and induced cell cycle arrest in the S phase – effects distinct from the activity of madecassic acid. This is the first study on the synthesis and cytotoxicity of madecassic acid–silybin conjugates, and of their testing against liver cancer cell lines and provides evidence for a distinct biological profile versus madecassic acid alone.

Rho-associated coiled-coil containing kinase (ROCK) plays an important role in inflammation. Herein, a series of compounds were designed and synthesized as ROCK inhibitors based on the structure-based drug design (SBDD) strategy and were evaluated for cytotoxicity, antioxidant activity and anti-inflammatory activity. Among them, compound DC24 was identified as the optimal hit in enzymatic screening with an IC₅₀ value of 0.124 μM against ROCK2 and 50-fold selectivity over ROCK1. DC24 has a novel lipid amide scaffold with a bis(4-fluorophenyl)methyl substituent, and DC24 is the first ROCK2 inhibitor interacting with the hinge region of ROCK2 via the 1,2-dithiolan-3-yl motif, which has been confirmed by the binding model of DC24 with ROCK2. In a complete Freund's adjuvant (CFA) induced acute inflammation model, DC24 at a dose of 5 mg kg⁻¹ exhibited an anti-inflammatory effect better than that of belumosudil. Furthermore, DC24 exhibits good safety in vivo.

The natural marine betaine norzooanemonin (1,3-dimethylimidazolim-4-carboxylate) and its methyl and ethyl esters were used as ligand precursors to prepare a systematic series (12 members) of neutral monocarbene gold(I/III) and cationic dicarbene gold(I/III) complexes. The complexes were evaluated as inhibitors of bacterial thioredoxin reductase and for their antiproliferative and antimicrobial activities. While gold complexes with the parent norzooanemonin scaffold resulted in overall poor performance, the more lipophilic esters proved to be highly bioactive agents, related to their higher cellular uptake. The monocarbene gold(I/III) complexes showed significant potency as inhibitors of bacterial thioredoxin reductase. In most assays, the efficacy of both gold(I) and gold(III) analogues was found to be comparable. The cytotoxicity of dicarbene gold(I/III) complexes against cancer cells was strong, in some cases exceeding that of the standard reference auranofin.

Herein, we report the synthesis and anticancer properties of 21 new 1,3,4-thiadiazole-2-yl-imino-thiazolidine-4-one containing binary heterocyclic molecules. Cytotoxicity of the synthesized molecules was evaluated on various in vitro cancer cell lines (MCF-7, PC3, 4T1, MDA-MB-231, and MOC2) and normal human embryonic cell lines (HEK-293) via MTT assay. The cytotoxicity data of developed compounds was compared with the reference anticancer molecule BG45, a selective inhibitor of the HDAC3 enzyme. All compounds showed a significant cytotoxic effect higher than BG45 on tested cancer cell lines. Moreover, the compounds exhibited better selectivity on cancer cells than on normal cells. Among the molecules, compound 6e is the most potent in cytotoxic activity on MCF-7 cell lines (IC₅₀ value of 3.85 μM). Additional mechanistic investigation revealed that compound 6e promotes apoptosis (25.3%) and G0/G1 phase cell cycle arrest of MCF-7 cells. Also, compound 6e induces intracellular ROS accumulation and subsequent nuclear fragmentation. Hence, this research finds new hybrid molecules active against in vitro cancer cells.

Bcr-Abl is successfully applied to drug discovery as a CML therapeutic target, but point mutation resistance has become a major challenge in the clinical treatment of CML. Our previous studies have shown that the introduction of amino acids as flexible linkers and heterocyclic structures as HBMs can achieve potent inhibition of Bcr-Abl^T315I. In continuation of these studies, we further enriched the linker types by developing a library of compounds with tert-leucine or serine as a linker. Biological results showed that these compounds exhibited enhanced inhibition against Bcr-Abl^WT and Bcr-Abl^T315I kinases as well as improved antiproliferative activity in leukemia cell assays compared to previously disclosed compounds. In particular, compounds TL8, TL10, BS4, BS10, SR5 and SR11 exhibited potent inhibitory activities against Ba/F3 cells bearing a T315I mutant. Additionally, compounds TL8, BS4 and SR5 effectively induced K562 cell apoptosis, arrested the cell cycle at the S or G2/M phase, and inhibited the phosphorylation of Bcr-Abl and STAT5 in a dose-dependent manner. Docking studies verified the rationality of tert-leucine or serine as a flexible linker and indicated that phenylpyridine with an amide side chain favored the potency of these inhibitors. Moreover, ADME prediction suggested that the tested compounds had a favorable safety profile. Thus, tert-leucine or serine can be used as a promising class of flexible linkers for Bcr-Abl inhibitors with heterocyclic structures as HBMs, and compounds BS4, SR5, and especially TL8, can be used as starting points for further optimization.

Calculable physicochemical descriptors are a useful guide to assist compound design in medicinal chemistry. It is well established that controlling size, lipophilicity, hydrogen bonding, flexibility and shape, guided by descriptors that approximate to these properties, can greatly increase the chances of successful drug discovery. Many therapeutic targets and new modalities are incompatible with the optimal ranges of these properties and thus there is much interest in approaches to find oral drug candidates outside of this space. These considerations have been a focus for a while and hence we analysed the physicochemical properties of oral drugs approved by the FDA from 2000 to 2022 to assess if such concepts had influenced the output of the drug-discovery community. Our findings show that it is possible to find drug molecules that lie outside of the optimal descriptor ranges and that large molecules in particular (molecular weight >500 Da) can be oral drugs. The analysis suggests that this is more likely if lipophilicity, hydrogen bonding and flexibility are controlled. Crude physicochemical descriptors are useful in that regard but more accurate and robust means of understanding substructural classes, shape and conformation are likely to be required to improve the chances of success in this space.

Dihydroorotate dehydrogenase (DHODH), an enzyme that plays a critical role in the de novo pyrimidine biosynthesis, has been recognized as a promising target for the treatment of diseases that involve cellular proliferation, such as autoimmune diseases and cancers. Pharmacological inhibition of human DHODH (hDHODH) that offers a potential therapeutic strategy for the treatment in adult subjects with acute myeloid leukemia (AML) has recently been supported by phase I/II clinical trials for the treatment of patients with relapsed/refractory AML. To facilitate the development of optimized hDHODH inhibitors, the presence of an in vivo imaging probe that is able to demonstrate in vivo target engagement is critical and desirable. Brequinar is one of the most potent hDHODH inhibitors so far discovered. In this work, we use a copper-mediated radiofluorination (CMRF) strategy and compare the chemical design and radiosynthesis starting from either pinacole boronate p-nitrobenzyl ester (4) or tributylstannate (tin) p-nitrobenzyl ester (5), chosen for their suitability as a precursor to [¹⁸F]brequinar. We report here the design, synthesis, radiolabeling and characterization of [¹⁸F]brequinar, and a preliminary PET imaging study of DHODH in vivo. This study provides the strategies to create [¹⁸F]brequinar, the first hDHODH inhibitor PET radiotracer, which will facilitate its use as a tool (theranostics) for hDHODH drug development and for diagnosis and monitoring therapeutic efficacy in AML and cancers.

The synthesis, anticancer activity, and metabolic stability of di-arylated 1,2,4-triazole molecules have been reported. Utilizing an efficient programmed arylation technique which starts from commercially available 3-bromo-1H-1,2,4-triazole, a series of therapeutic agents have been synthesized and screened against three human breast cancer cell lines, MDA-MB-231, MCF-7, and ZR-75-1, via an in vitro growth inhibition assay. At 10 μM concentration, 4k, 4m, 4q, and 4t have displayed good anticancer potency in the MCF-7 cell line, among which 4q has shown the best efficacy (IC₅₀ = 4.8 μM). Mechanistic investigations of 4q have indicated the elevation of the pro-apoptotic BAX protein in the malignant cells along with mitochondrial outer membrane permeabilization which are hallmarks of apoptosis. Further metabolic stability studies in diverse liver microsomes have provided insights into the favorable pharmacokinetic properties of 4q in humans, establishing it as a promising lead compound of this series that deserves further investigation.