Discovery of a New Series of Naphthamides as Potent VEGFR-2 Kinase Inhibitors

Photoinduced Site-Selective Aryl C-H Borylation with Electron-Donor-Acceptor Complex Derived from B2Pin2 and Isoquinoline

Due to boron's metalloid properties, aromatic boron reagents are prevalent synthetic intermediates. The direct borylation of aryl C-H bonds for producing aromatic boron compounds offers an appealing, one-step solution. Despite significant advances in this field, achieving regioselective aryl C-H bond borylation using simple and readily available starting materials still remains a challenge. In this work, we attempted to enhance the reactivity of the electron-donor-acceptor (EDA) complex by selecting different bases to replace the organic base (NEt3) used in our previous research. To our delight, when using NH4HCO3 as the base, we have achieved a mild visible-light-mediated aromatic C-H bond borylation reaction with exceptional regioselectivity (rr > 40:1 to single isomers). Compared with our previous borylation methodologies, this protocol provides a more efficient and broader scope for aryl C-H bond borylation through the use of N-Bromosuccinimide. The protocol's good functional-group tolerance and excellent regioselectivity enable the functionalization of a variety of biologically relevant compounds and novel cascade transformations. Mechanistic experiments and theoretical calculations conducted in this study have indicated that, for certain arenes, the aryl C-H bond borylation might proceed through a new reaction mechanism, which involves the formation of a novel transient EDA complex.

Preclinical and early clinical studies of a novel compound SYHA1813 that efficiently crosses the blood-brain barrier and exhibits potent activity against glioblastoma

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults and is poorly controlled. Previous studies have shown that both macrophages and angiogenesis play significant roles in GBM progression, and co-targeting of CSF1R and VEGFR is likely to be an effective strategy for GBM treatment. Therefore, this study developed a novel and selective inhibitor of CSF1R and VEGFR, SYHA1813, possessing potent antitumor activity against GBM. SYHA1813 inhibited VEGFR and CSF1R kinase activities with high potency and selectivity and thus blocked the cell viability of HUVECs and macrophages and exhibited anti-angiogenetic effects both in vitro and in vivo. SYHA1813 also displayed potent in vivo antitumor activity against GBM in immune-competent and immune-deficient mouse models, including temozolomide (TMZ) insensitive tumors. Notably, SYHA1813 could penetrate the blood-brain barrier (BBB) and prolong the survival time of mice bearing intracranial GBM xenografts. Moreover, SYHA1813 treatment resulted in a synergistic antitumor efficacy in combination with the PD-1 antibody. As a clinical proof of concept, SYHA1813 achieved confirmed responses in patients with recurrent GBM in an ongoing first-in-human phase I trial. The data of this study support the rationale for an ongoing phase I clinical study (ChiCTR2100045380).

Cytotoxic, Apoptosis-Inducing Activities, and Molecular Docking of a New Sterol from Bamboo Shoot Skin Phyllostachys heterocycla var. pubescens

Phytochemical screening of nonpolar fractions from the methanol extract of the Bamboo shoot skin Phyllostachys heterocycla var. pubescens resulted in the isolation of a new sterol-glucoside-fatty acid derivative (6'-O-octadeca-8'',11''-dienoyl)-sitosterol-3-O-β-d-glucoside (1), together with six known compounds. The chemical structures of the pure isolated compounds were deduced based on different spectral data. The isolated compounds were assessed to determine their cytotoxic activity, and the results were confirmed by determining their apoptotic activity. Compound 1 was more cytotoxic against the MCF-7 cells (IC50 = 25.8 µM) compared to Fluorouracil (5-FU) (26.98 µM), and it significantly stimulated apoptotic breast cancer cell death with 32.6-fold (16.63% compared to 0.51 for the control) at pre-G1 and G2/M-phase cell cycle arrest and blocked the progression of MCF-7 cells. Additionally, RT-PCR results further confirmed the apoptotic activity of compound 1 by the upregulation of proapoptotic genes (P53; Bax; and caspases 3, 8, and 9) and downregulation of the antiapoptotic genes (BCL2). Finally, the identified compounds, especially 1, were found to have high binding affinity towards both tyrosine-specific protein kinase (TPK) and vascular endothelial growth factor receptor (VEGFR-2) through the molecular docking studies that highlight its mode of action.

Design, synthesis, and biological evaluations of novel 3-amino-4-ethynyl indazole derivatives as Bcr-Abl kinase inhibitors with potent cellular antileukemic activity

Breakpoint cluster region-Abelson (Bcr-Abl) kinase is a key driver in the pathophysiology of chronic myelogenous leukemia (CML). Broadening the chemical diversity of Bcr-Abl kinase inhibitors with novel chemical entities possessing favorable target potency and cellular efficacy is a current medical demand for CML treatment. In this respect, a new series of ethynyl bearing 3-aminoindazole based Bcr-Abl inhibitors has been designed, synthesized, and biologically evaluated. The target compounds were designed based on introducing the key structural features of ponatinib, alkyne spacer and diarylamide, into the previously reported indazole II to improve its Bcr-Abl inhibitory activity and overcome its poor cellular potency. All target compounds elicited potent activity against Bcr-Abl^WT with sub-micromolar IC₅₀ values ranging 4.6-667 nM. In addition, certain derivatives exhibited promising potency over the clinically imatinib-resistant Bcr-Abl^T315I. Among the target molecules, compounds 9c, 9h and 10c stood as the most potent derivatives with IC₅₀ values of 15.4 nM, 4.6 nM, and 25.8 nM, respectively, against Bcr-Abl^WT. Interestingly, 9h showed 2 folds and 3.6 times superior potency to the lead indazole II and 10c, respectively, against Bcr-Abl^T315I. Molecular docking of 9h pointed out its possibility to be a type II kinase inhibitor. Furthermore, all compounds, except 9b, showed highly potent antiproliferative activity against the Bcr-Abl positive leukemia K562 cell (MTT assay) surpassing the modest activity of lead indazole II. Moreover, the most potent members 9h and 10c exerted potent antileukemic activity against NCI leukemia panel, particularly K562 cell (SRB assay) with GI₅₀ less than 10 nM, being superior to the FDA approved drug imatinib. Further biochemical hERG and cellular toxicity, phosphorylation assay, and NanoBRET target engagement of 9h underscored its merits as a promising candidate for CML therapy.

Design and synthesis of new 1,6-dihydropyrimidin-2-thio derivatives targeting VEGFR-2: Molecular docking and antiproliferative evaluation

A series of new 1,6-dihydropyrimidin-2-thiol derivatives (scaffold A) as VEGFR-2 inhibitors has been designed and synthesized. Compounds 3a, 3b, 3e and 4b have been selected for in vitro anticancer screening by the National Cancer Institute. Compound 3e showed remarkable anticancer activity against most of the cell lines tested, where a complete cell death against leukemia, non-small cell lung cancer, colon, CNS, melanoma, and breast cancer cell lines was observed. In vitro five dose tests showed that compound 3e had high activity against most of the tested cell lines with GI₅₀ ranging from 19 to 100 μM and selectivity ratios ranging between 0.75 and 1.71 at the GI₅₀ level. VEGFR-2-kinase was tested against 3a, 3b, 3e, 4b and sorafenib was used as a reference. Compounds 3a and 3e were the most potent analogues with IC₅₀ values of 386.4 nM and 198.7 nM against VEGFR-2, respectively, in comparison to sorafenib (IC₅₀ = 0.17 nM). The results of the docking study showed a good fitting of the new compounds to the active site of VEGFR-2 with binding free energies in the range of -9.80 to -11.25 kcal/mol compared to -12.12 kcal/mol for sorafenib. Compounds 4a-e with the hydroxyimino group had a higher affinity to VEGFR-2 than their parent derivatives 3a-e.

Design, Synthesis, and In Vitro Evaluation of Benzofuro[3,2-c]Quinoline Derivatives as Potential Antileukemia Agents

Herein, we design and synthesize an array of benzofuro[3,2-c]quinolines starting from 3-(2-methoxyphenyl)quinolin-4(1H)ones via a sequential chlorination/demethylation, intramolecular cyclization pathway. This sequential transformation was efficient, conducted under metal-free and mild reaction conditions, and yielded corresponding benzofuro[3,2-c]quinolines in high yields. In vitro biological evaluation indicated that such type of compounds showed excellent antileukemia activity and selectivity, and therefore may offer a promising hit compound for developing antileukemia compounds.

Discovery of biphenyl-aryl ureas as novel VEGFR-2 inhibitors. Part 4: exploration of diverse hinge-binding fragments

VEGFR-2 plays an essential role in angiogenesis and is an important target for cancer therapy. A series of biphenyl-aryl ureas were synthesized and evaluated as novel VEGFR-2 inhibitors. The pyridine, methylamine carbonyl pyridine and pivaloyl amide pyridine were introduced as novel hinge binding fragment. The majority of title compounds displayed potent VEGFR-2 inhibition. In particular, L1, L9, W14 and W15 exhibited significant enzymatic inhibitory activity with IC50 values of 0.36nM, 0.22nM, 0.15nM and 0.14nM. Compounds L1, L9 and W15 displayed potent antiproliferative activity against A549 and SMMC-7721 cells. SAR study suggested that incorporation of 3-trifluoromethyl and methylamine carbonyl on terminal pyridine could improve VEGFR-2 inhibitory activity. Molecular docking illustrated that urea moiety formed two critical hydrogen bonds with the DFG residues of VEGFR-2. The results indicated that these biphenyl-aryl ureas could serve as promising lead compounds for further optimization.

Discovery of anilinopyrimidine-based naphthamide derivatives as potent VEGFR-2 inhibitors

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays an important role in tumor angiogenesis, and inhibition of the VEGFR-2 signaling pathway has emerged as an attractive strategy for the treatment of cancer.