Discovery of a prominent dual-target DDR1/EGFR inhibitor aimed DDR1/EGFR-positive NSCLC.

This study aimed to develop the first dual-target small molecule inhibitor concurrently targeting Discoidin domain receptor 1 (DDR1) and Epidermal growth factor receptor (EGFR), which play a crucial interdependent roles in non-small cell lung cancer (NSCLC), demonstrating a synergistic inhibitory effect. A series of innovative dual-target inhibitors for DDR1 and EGFR were discovered. These compounds were designed and synthesized using structural optimization strategies based on the lead compound BZF02, employing 4,6-pyrimidine diamine as the core scaffold, followed by an investigation of their biological activities. Among these compounds, D06 was selected and showed micromolar enzymatic potencies against DDR1 and EGFR. Subsequently, compound D06 was observed to inhibit NSCLC cell proliferation and invasion. Demonstrating acceptable pharmacokinetic performance, compound D06 exhibited its anti-tumor activity in NSCLC PC-9/GR xenograft models without apparent toxicity or significant weight loss. These collective results showcase the successful synthesis of a potent dual-targeted inhibitor, suggesting the potential therapeutic efficacy of co-targeting DDR1 and EGFR for DDR1/EGFR-positive NSCLC.

Discovery of 4-methoxy-N-(1-naphthyl)benzenesulfonamide derivatives as small molecule dual-target inhibitors of tubulin and signal transducer and activator of transcription 3 (STAT3) based on ABT-751.

Overexpressed tubulin and continuously activated STAT3 play important roles in the development of many cancers and are potential therapeutic targets. A series of 4-methoxy-N -(1-naphthalene) benzenesulfonamide derivatives were designed and optimized based on ß-tubulin inhibitor ABT-751 to verify whether STAT3 and tubulin dual target inhibitors have better antitumor effects. Compound DL14 showed strong inhibitory activity against A549, MDA-MB-231 and HCT-116 cells in vitro with IC50 values of 1.35 µM, 2.85 µM and 3.04 µM, respectively. Further experiments showed that DL14 not only competitively bound to colchicine binding site to inhibit tubulin polymerization with IC50 values 0.83 µM, but also directly bound to STAT3 protein to inhibit STAT3 phosphorylation with IC50 value of 6.84 µM. Three other compounds (TG03, DL15, and DL16) also inhibit this phosphorylation. In terms of single target inhibition, DL14 is slightly inferior to positive drugs, but it shows a good anti-tumor effect in vivo, and can inhibit >80% of xenograft tumor growth. This study describes a novel 4-methoxy-N-(1-naphthyl) benzenesulfonamide skeleton as an effective double-targeted anticancer agent targeting STAT3 and tubulin.

Design, synthesis and biological evaluation of 4-bromo-N-(3,5-dimethoxyphenyl)benzamide derivatives as novel FGFR1 inhibitors for treatment of non-small cell lung cancer.

A series of 4-bromo-N-(3,5-dimethoxyphenyl)benzamide derivatives were designed and synthesised as novel fibroblast growth factor receptor-1 (FGFR1) inhibitors. We found that one of the most promising compounds, C9, inhibited five non-small cell lung cancer (NSCLC) cell lines with FGFR1 amplification, including NCI-H520, NCI-H1581, NCI-H226, NCI-H460 and NCI-H1703. Moreover, the IC50 values for the compound C9 were 1.36 ± 0.27 µM, 1.25 ± 0. 23 µM, 2.31 ± 0.41 µM, 2.14 ± 0.36 µM and 1.85 ± 0.32 µM, respectively. The compound C9 arrested the cell cycle at the G2 phase in NSCLC cell lines. The compound C9 also induced cellular apoptosis and inhibited the phosphorylation of FGFR1, PLCγ1 and ERK in a dose-dependent manner. In addition, molecular docking experiments showed that compound C9 binds to FGFR1 to form six hydrogen bonds. Taken together, our data suggested that the compound C9 represented a promising lead compound-targeting FGFR1.

An UPLC-MS/MS method for the determination of EAI045 in plasma and tissues and its application to pharmacokinetic and distribution studies in rats.

EAI045 represents a fourth generation allosteric EGFR TKI compound which targets T790M and C797S EGFR mutants. The study reported herein describes a method to explore the distribution of EAI045 in rat tissues as well as to quantify it in plasma. The method used here is an ultra-performance liquid chromatography-tandem mass spectrometry with high sensitivity and selectivity. An ACQUITY UPLC BEN HILIC column with dimensions of 2.1 × 100 mm, 1.7 µm was used to separate the analytes and IS. As mobile phase acetonitrile as well as 0.1 % of formic acid/water was used combined with an elution gradient and 0.40 mL/min flow rate. This eluent was also used for electrospray ionization in positive ion mode. A mode on multiple reactions monitoring (MRM) was also employed in the quantification. This quantification included the use of targeted segment ions with m/z 384.1→100.8 for EAI045, and m/z 285.1→193.3 for IS, respectively. It was found that the linearity of this method was appropriate and the concentration range could be kept within a range of 2-2000 ng/mL for EAI045 in rat plasma and tissues. The level of EAI045 was found to be highest in the liver, followed by kidneys, lungs and heart. Furthermore, the results provided evidence that EAI045 could be absorbed quickly and distributed widely in different tissue types.

Fibroblast growth factor 2 protects against renal ischaemia/reperfusion injury by attenuating mitochondrial damage and proinflammatory signalling.

Ischaemia-reperfusion injury (I/RI) is a common cause of acute kidney injury (AKI). The molecular basis underlying I/RI-induced renal pathogenesis and measures to prevent or reverse this pathologic process remains to be resolved. Basic fibroblast growth factor (FGF2) is reported to have protective roles of myocardial infarction as well as in several other I/R related disorders. Herein we present evidence that FGF2 exhibits robust protective effect against renal histological and functional damages in a rat I/RI model. FGF2 treatment greatly alleviated I/R-induced acute renal dysfunction and largely blunted I/R-induced elevation in serum creatinine and blood urea nitrogen, and also the number of TUNEL-positive tubular cells in the kidney. Mechanistically, FGF2 substantially ameliorated renal I/RI by mitigating several mitochondria damaging parameters including pro-apoptotic alteration of Bcl2/Bax expression, caspase-3 activation, loss of mitochondrial membrane potential and KATP channel integrity. Of note, the protective effect of FGF2 was significantly compromised by the KATP channel blocker 5-HD. Interestingly, I/RI alone resulted in mild activation of FGFR, whereas FGF2 treatment led to more robust receptor activation. More significantly, post-I/RI administration of FGF2 also exhibited robust protection against I/RI by reducing cell apoptosis, inhibiting the release of damage-associated molecular pattern molecule HMBG1 and activation of its downstream inflammatory cytokines such as IL-1α, IL-6 and TNF α. Taken together, our data suggest that FGF2 offers effective protection against I/RI and improves animal survival by attenuating mitochondrial damage and HMGB1-mediated inflammatory response. Therefore, FGF2 has the potential to be used for the prevention and treatment of I/RI-induced AKI.

Synthesis and Evaluation of Phenylxanthine Derivatives as Potential Dual A2AR Antagonists/MAO-B Inhibitors for Parkinson's Disease.

The aim of this research was to prove the speculation that phenylxanthine (PX) derivatives possess adenosine A2A receptor (A2AR)-blocking properties and to screening and evaluate these PX derivatives as dual A2AR antagonists/MAO-B inhibitors for Parkinson's disease. To explore this hypothesis, two series of PX derivatives were prepared and their antagonism against A2AR and inhibition against MAO-B were determined in vitro. In order to evaluate further the antiparkinsonian properties, pharmacokinetic and haloperidol-induced catalepsy experiments were carried out in vivo. The PX-D and PX-E analogues acted as potent A2AR antagonists with Ki values ranging from 0.27 to 10 µM, and these analogues displayed relatively mild MAO-B inhibition potencies, with inhibitor dissociation constants (Ki values) ranging from 0.25 to 10 µM. Further, the compounds PX-D-P6 and PX-E-P8 displayed efficacious antiparkinsonian properties in haloperidol-induced catalepsy experiments, verifying that these two compounds were potent A2AR antagonists and MAO-B inhibitors. We conclude that PX-D and PX-E analogues are a promising candidate class of dual-acting compounds for treating Parkinson's disease.

Design, Synthesis, and Biological Activity of Tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine Derivatives as Anti-Inflammatory Agents.

We designed and synthesized 26 prototype compounds and studied their anti-inflammatory activity and underlying molecular mechanisms. The inhibitory effects of the compounds on the production of nitric oxide (NO), cytokines, inflammatory-related proteins, and mRNAs in lipopolysaccharide (LPS)-stimulated macrophages were determined by the Griess assay, Enzyme linked immunosorbent assay (ELISA), Western blot analysis, and Reverse transcription-Polymerase Chain Reaction (RT-PCR), respectively. Our results indicated that treatment with A2, A6 and B7 significantly inhibited the secretion of NO and inflammatory cytokines in RAW264.7 cells without demonstrable cytotoxicity. It was also found that A2, A6 and B7 strongly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase enzyme COX-2, and prevented nuclear translocation of nuclear factor κB (NF-κB) p65 by inhibiting the degradation of p50 and IκBα. Furthermore, the phosphorylation of mitogen-activated protein kinase (MAPKs) in LPS-stimulated RAW264.7 cells was significantly inhibited by A2, A6 and B7. These findings suggest that A2, A6 and B7 may operate as an effective anti-inflammatory agent through inhibiting the activation of NF-κB and MAPK signaling pathways in macrophages. Moreover, rat paw swelling experiments showed that these compounds possess anti-inflammatory activity in vivo, with compound A6 exhibiting similar activities to the reference drug Indomethacin.

Design, synthesis and preliminary biological evaluation of C-8 substituted guanine derivatives as small molecular inhibitors of FGFRs.

Two series of C-8 substituted guanine derivatives were synthesized, one bearing 2-amino substitutions and the other bearing 2-acetamide substitutions. Biological activity tests showed that almost all of them possessed some extent of antitumor activities, and were with lower toxicity against normal human liver HL7702 cells than AZD4547 (the positive control). Among them, N-[8-(4-bromo-1H-indol-3-yl)-6-hydroxy-9H-purin-2-yl]-acetamide exhibited a relatively satisfied inhibition against FGFR1 kinase with IC50 of 1.56 µM and specifically against A549 cells with IC50 of 8.28 µM and B16-F10 cells with IC50 of 6.59 µM. Above all, the introduction of large substituents such as indolyl groups at 8-position of the guanine scaffold probably achieves higher selectivity for FGFR1 as compared with AZD4547.

Synthesis and evaluation of biological and antitumor activities of 5,7-dimethyl- oxazolo[5,4-d]pyrimidine-4,6(5H,7H)-dione derivatives as novel inhibitors of FGFR1.

A series of 5,7-dimethyl-oxazolo[5,4-d]pyrimidine-4,6(5H,7H)-dione derivatives, N5a-5l, was designed, synthesized and evaluated for their FGFR1-inhibition ability as well as cytotoxicity against three cancer cell lines (H460, B16F10 and A549) in vitro. Several compounds displayed good-to-excellent potency against these cancer cell lines compared to SU5402. Structure-activity relationship analyses indicated that compounds with a rigid structure and more heteroatoms at the side chain of the parent ring were more effective than those without these substitutions. The compound N5g (37.4% FGFR1 inhibition at 1.0 µM) was identified to have the most potent antitumor activities, with IC50 values of 5.472, 4.260 and 5.837 µM against H460, B16F10 and A549 cell lines, respectively. Together, our results suggest that 5,7-dimethyl-oxazolo[5,4-d]pyrimidine-4,6(5H,7H)-dione derivatives may serve as potential agents for the treatment of FGFR1-mediated cancers.

Synthesis, anti-tumor activity, and structure-activity relationships of curcumol derivatives.

Using curcumol that was extracted from the volatile oil of Rhizoma Curcumae as the raw material, its derivatives were synthesized and purified. The structures of these compounds were confirmed by (1)H, (13)C NMR, and mass spectral data. The test compounds were evaluated for their in vitro anti-tumor activity against gastric cancer cell lines SGC-7901 and lung carcinoma cell line H460 by methyl thiazolyl tetrazolium chromatometry. Distinct structure-activity relationships of these curcumol derivatives were also revealed for inhibiting cell proliferation. Presence of electron-withdrawing groups or amino could increase the activity significantly, whereas esterification of 8-hydroxy diminished the anti-tumor activity. Many of the tested candidates exhibited higher inhibition efficiency than curcumol, suggesting that structural modifications could enhance its activity effectively.

Synthesis and biological evaluation of novel benzothiazole derivatives as potential anticancer and antiinflammatory agents.

Introduction: Cancer, a significant global health concern, necessitates innovative treatments. The pivotal role of chronic inflammation in cancer development underscores the urgency for novel therapeutic strategies. Benzothiazole derivatives exhibit promise due to their distinctive structures and broad spectrum of biological effects. This study aims to explore new anti-tumor small molecule drugs that simultaneously anti-inflammatory and anticancer based on the advantages of benzothiazole frameworks. Methods: The compounds were characterized by nuclear magnetic resonance (NMR), liquid chromatograph-mass spectrometer (LC-MS) and high performance liquid chromatography (HPLC) for structure as well as purity and other related physicochemical properties. The effects of the compounds on the proliferation of human epidermoid carcinoma cell line (A431) and human non-small cell lung cancer cell lines (A549, H1299) were evaluated by MTT method. The effect of compounds on the expression levels of inflammatory factors IL-6 and TNF-α in mouse monocyte macrophages (RAW264.7) was assessed using enzyme-linked immunosorbent assay (ELISA). The effect of compounds on apoptosis and cell cycle of A431 and A549 cells was evaluated by flow cytometry. The effect of compounds on A431 and A549 cell migration was evaluated by scratch wound healing assay. The effect of compounds on protein expression levels in A431 and A549 cells was assessed by Western Blot assay. The physicochemical parameters, pharmacokinetic properties, toxicity and drug similarity of the active compound were predicted using Swiss ADME and admetSAR web servers. Results: Twenty-five novel benzothiazole compounds were designed and synthesized, with their structures confirmed through spectrogram verification. The active compound 6-chloro-N-(4-nitrobenzyl) benzo[d] thiazol-2-amine (compound B7) was screened through a series of bioactivity assessments, which significantly inhibited the proliferation of A431, A549 and H1299 cancer cells, decreased the activity of IL-6 and TNF-α, and hindered cell migration. In addition, at concentrations of 1, 2, and 4 µM, B7 exhibited apoptosis-promoting and cell cycle-arresting effects similar to those of the lead compound 7-chloro-N-(2, 6-dichlorophenyl) benzo[d] thiazole-2-amine (compound 4i). Western blot analysis confirmed that B7 inhibited both AKT and ERK signaling pathways in A431 and A549 cells. The prediction results of ADMET indicated that B7 had good drug properties. Discussion: This study has innovatively developed a series of benzothiazole derivatives, with a focus on compound B7 due to its notable dual anticancer and anti-inflammatory activities. B7 stands out for its ability to significantly reduce cancer cell proliferation in A431, A549, and H1299 cell lines and lower the levels of inflammatory cytokines IL-6 and TNF-α. These results position B7B7 as a promising candidate for dual-action cancer therapy. The study's mechanistic exploration, highlighting B7's simultaneous inhibition of the AKT and ERK pathways, offers a novel strategy for addressing both the survival mechanisms of tumor cells and the inflammatory milieu facilitating cancer progression.

Inhibition of DDR1 promotes ferroptosis and overcomes gefitinib resistance in non-small cell lung cancer.

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which serves the critical pillar for the treatment of non-small cell lung cancer (NSCLC). However, the acquired resistance remains a challenge for its clinical application, for which, practical strategies to reverse gefitinib resistance in NSCLC are necessary. Ferroptosis, a programmed cell death driven by ferritin-dependent lipid peroxidation, involves in NSCLC progression and related chemoresistance. In our previous work, the self-synthesised EGFR inhibitor Yfq07 (N4, N6-disubstituted pyrimidine-4,6-diamine derivatives) displayed a considerable inhibitory effect on NSCLC both in vitro and in vivo. Herein, we observed that Yfq07 suppressed the proliferation of PC-9GR and HCC827GR cells, two gefitinib resistance NSCLC cell lines. Mechanically, Yfq07 inhibited the phosphorylation of the Discoidin Domain Receptor 1 (DDR1), a receptor tyrosine kinase (RTK) highly expressed in multiple cancers, accompanied by downregulated miR-3648 and upregulated SOCS2. Inhibition or knockdown of DDR1 suppressed the proliferation, migration, and invasion of gefitinib-resistant NSCLC cells, and on the other hand, also downregulated miR-3648 and promoted SOCS2 expression. More specifically, miR-3648 targeted the 3'UTR segment of SOCS2 mRNA and thus affecting the P-ERK signalling pathway to regulate the malignant behaviors of gefitinib-resistant NSCLC cells. Furthermore, Yfq07 also indirectly induced the ferroptosis of gefitinib-resistant NSCLC cells via SOCS2 triggered inhibition of xCT-GPX4 pathway. In conclusion, our study indicates that DDR1 inhibitor Yfq07 promotes ferroptosis and reverses gefitinib-resistance of NSCLC through DDR1-miR-3648-SOCS2 signalling pathway, which provides insights for targeted therapy of gefitinib-resistant NSCLC and drug developments targeting ferroptosis.

Synthesis and biological evaluation of nucleoside analogues than contain silatrane on the basis of the structure of acyclovir (ACV) as novel inhibitors of hepatitis B virus (HBV).

Hepatitis B virus (HBV) infection causes major public health problems worldwide. Acyclovir (ACV) is mainly used to inhibit herpes simplex virus (HSV) rather than HBV. In this study, we used the combination principle to design and synthesize nucleoside analogues that contain silatrane on the basis of the structure of ACV. We found that the compounds were effective inhibitors of HBV, both in vitro and in vivo. All of the compounds showed suppressive activity on the expression of HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) in the HepG2.2.15 cell line with low cytotoxicity. One of compounds was studied in HBV transgenic mice model, and the test results showed its ability to reduce the levels of HBsAg, HBeAg and HBV DNA by ELASE and qPCR. Furthermore, significant improvement of T lymphocyte was observed after treatment, as evaluated by flow cytometry (FCM).

Design and synthesis of 8-substituted benzamido-phenylxanthine derivatives as MAO-B inhibitors.

Monoamine oxidase-B (MAO-B) inhibitor has been used as neuroprotectants to treat the motor deficits of Parkinson's disease (PD). We designed and synthesized a class of 8-substituted benzamido-phenylxanthine derivatives as MAO-B inhibitors. The compounds have various inhibitory effects, with compound 6a having a K(i) value of 0.26 µM. Their promising activity in vitro suggests potential use in the treatment of PD.

Design, synthesis and inhibitory activities of 8-(substituted styrol-formamido)phenyl-xanthine derivatives on monoamine oxidase B.

The design and synthesis of two series of 8-(substituted styrol-formamido)phenyl-xanthine derivatives are described. Their in vitro monoamine oxidase B (MAO-B) inhibition were tested and the effect of substituents on the N-7, phenyl and the substituted positions are discussed. It was observed that compound 9b displayed significant MAO-B inhibition activity and selectivity, fluorine substitution plays a key role in the selectivity of MAO-B inhibition, and the styrol-formamido group at position-3' may enhance the activity and selectivity of 8-phenyl-xanthine analogues. These results suggest that such compounds may be utilized for the development of new candidate MAO-B inhibitors for treatment of Parkinson's disease.

Discovery of N-substituted sulfamoylbenzamide derivatives as novel inhibitors of STAT3 signaling pathway based on Niclosamide.

Signal transducer and activator of transcription 3 (STAT3) has been confirmed as an attractive therapeutic target for cancer therapy. Herein, we designed and synthesized a series of N-substituted Sulfamoylbenzamide STAT3 inhibitors based on small-molecule STAT3 inhibitor Niclosamide. Compound B12, the best active compound of this series, was identified as an inhibitor of IL-6/STAT3 signaling with an IC50 of 0.61-1.11 µM in MDA-MB-231, HCT-116 and SW480 tumor cell lines with STAT3 overexpression, by inhibiting the phosphorylation of STAT3 of Tyr705 residue and the expression of STAT3 downstream genes, inducing apoptosis and inhibiting the migration of cancer cells. Furthermore, in vivo study revealed that compound B12 suppressed the MDA-MB-231 xenograft tumor growth in nude mice at the dose of 30 mg/kg (i.g.), which has better antitumor activity than the positive control Niclosamide. More importantly, B12 is an orally bioavailable anticancer agent as a promising candidate for further development.

Synthesis and biological evaluation of novel N-substituted benzamides as anti-migration agents for treatment of osteosarcoma.

A novel series of novel N-substituted (indole or indazole) benzamides were synthesized, and their anti-tumor properties were evaluated. The majority of tested compounds possessed moderate cytotoxicity, but inspiringly, we verified that active compound 5d presents an astonishing advantage by inhibiting the adhesion, migration, and invasion of osteosarcoma (OS) cells in vitro. Mechanistically, we confirmed 5d inhibited the migration ability of OS cells via the expression of genes related to adhesion, migration, and invasion. This effects of 5d suggest that it can be used as a potential chemotherapeutic drug to some aggressive and/or metastatic cancers, as well as in combination with other clinical anti-cancer drugs. In turn, this could enhance the therapeutic effect or reduce the risk of cell migration.

Determination of piracetam in rat plasma by LC-MS/MS and its application to pharmacokinetics.

A sensitive and selective liquid chromatography-tandem mass spectrometry method for the determination of piracetam in rat plasma was developed and validated over the concentration range of 0.1-20 µg/mL. After addition of oxiracetam as internal standard, a simplified protein precipitation with trichloroacetic acid (5%) was employed for the sample preparation. Chromatographic separation was performed by a Zorbax SB-Aq column (150 × 2.1 mm, 3.5 µm). The mobile phase was acetonitrile-1% formic acid in water (10:90 v/v) delivered at a flow rate of 0.3 mL/min. The MS data acquisition was accomplished in multiple reaction monitoring mode with a positive electrospray ionization interface. The lower limit of quantification was 0.1 µg/mL. For inter-day and intra-day tests, the precision (RSD) for the entire validation was less than 9%, and the accuracy was within the 94.6-103.2% range. The developed method was successfully applied to pharmacokinetic studies of piracetam in rats following single oral administration dose of 50 mg/kg.

Discovery of 4,6-pyrimidinediamine derivatives as novel dual EGFR/FGFR inhibitors aimed EGFR/FGFR1-positive NSCLC.

FGF2-FGFR1 autocrine pathway activation reduces the sensitivity of non-small cell lung cancer (NSCLC) cells to EGFR inhibitors like Gefitinib. Therefore, dual-specific drugs targeting EGFR and FGFR with high selectivity and activity are required. Through structure analysis of excellent EGFR inhibitors and FGFR inhibitors, we designed and synthesized 33 4,6-pyrimidinediamine derivatives as dual EGFR and FGFR inhibitors and selected BZF 2 as a potential EGFR and FGFR inhibitor after initial cell screening. Then, through kinase testing and western blot analysis, BZF 2 was defined as a dual EGFR and FGFR inhibitor with high selectivity 1and activity. Biological evaluation of NSCLC cell lines with the FGF2-FGFR1 autocrine loop indicated that BZF 2 significantly inhibited cell proliferation (IC50 values for H226 and HCC827 GR were 2.11 µM, and 0.93 µM, respectively), cell migration, and induced cell apoptosis and cell cycle arrest. Anti-tumor activity test in vivo showed that BZF 2 obviously shrank tumor size. Therefore, BZF 2 is a highly selective and potent dual EGFR/FGFR compound with promising therapeutic effects against EGFR/FGFR1-positive NSCLC.

Design, synthesis and activity of novel 2,6-disubstituted purine derivatives, potential small molecule inhibitors of signal transducer and activator of transcription 3.

Sustained activation of STAT3 is closely related to the cancer development, but the inhibitors for STAT3 overexpression are still in the clinical research stage. In this study, a series of 2,6-disubstituted purine derivatives were designed and synthesized, and their biological activities, as small molecule inhibitors of STAT3, were assessed. Compound PD26-TL07 exhibited remarkable antiproliferative activity against three cancer cell lines (IC50 values for HCT-116, SW480 and MDA-MB-231 were 1.77 ±â€¯0.35, 1.51 ±â€¯0.19, and 1.25 ±â€¯0.38 µM, respectively). Moreover, detailed biological assays revealed that PD26-TL07 could effectively inhibited STAT3 phosphorylation, and had little inhibition to others'. The newly discovered PD26-TL07 displayed an expecting anticancer effect both in vitro and in vivo. The molecular docking models revealed that PD26-TL07 could bind to the SH2 domain of STAT3. Three additional compounds (PD26-BZ01, PD26-TL03 and PD26-AS06) were also able to inhibit this phosphorylation. This study described novel 2,6-disubstituted purine derivatives as potent anticancer agents targeting STAT3.