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• A new derivative of podophyllotoxin (GHGT-17) was synthesized by incorporation of cyclopropyl, formyl, piperazinyl groups. • GHGT-17 exhibits significant cytotoxicity against a variety of cancer cells. • The IC 50 of GHGT-17 was less than 100 nM against A549 and H460 cells and greater than 100 µM against 16HBE cells. • In silico ADMET analysis suggests GHGT-17 is unlikely to toxic to normal organs. • Molecular docking study indicates that GHGT-17 could directly bind to the colchicine binding pocket of tubulin. Podophyllotoxin (PPT) is a naturally occurring lignan extracted from the rhizomes of the Podophyllum plant. It exhibits toxicity towards a broad spectrum of cancer cells and can induce cell death by inhibiting the polymerization of microtubule proteins. In our pursuit of more potent anticancer drug candidates, 4α-(cyclopropyl formylpiperazinyl)-4-deoxypodophyllotoxin (GHGT-17) was successfully synthesized by introducing a piperazine group, formyl group, and cyclopropyl group at the C-4 position of PPT. The activity of GHGT-17 against various types of cancer cells was evaluated using the MTT assay. It exhibited significant potency against lung cancer cells, with IC 50 values of 0.080 ± 0.020 μM (A549) and 0.086 ± 0.004 μM (H460), without obvious toxicity towards lung epithelial cells 16HBE (IC 50 > 100 μM). Further investigations demonstrated that GHGT-17 induced morphological changes in A549 and H460 cells, inhibited proliferation in a time- and dose-dependent manner. Furthermore, GHGT-17 inhibited the formation of cell colonies in a dose-dependent manner. It was found to inhibit cell migration, arrest the cell cycle in the G2/M phase, induce nuclear wrinkling, decrease mitochondrial membrane potential, and inhibit microtubule protein polymerization. These effects ultimately contribute to the induction of endogenous apoptosis. In silico studies, ADMET analysis revealed that GHGT-17 exhibited a satisfactory bioavailability with good water solubility, easy absorption, and well-proportioned distribution in the body. Molecular docking was performed to predict the binding mode and interactions of GHGT-17 with tubulin protein (1SA0). Additionally, GHGT-17 was submitted to molecular dynamics simulation and RMSD, RMSF, Rg, hydrogen bonding was analyzed. The complex showed a rather low binding free energy (−36.37 kJ mol−1) and thus exhibited a superior binding affinity towards to tubulin protein. In summary, the combined results indicated that GHGT-17 exhibits promise as a prospective potential novel drug candidate worthy of further investigation for its potential application in lung cancer therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

The root of Croton crassifolius has been used as a traditional Chinese medicine (TCM), called Radix Croton Crassifolius, and commonly known as "Ji Gu Xiang" in Chinese. Its medicinal value has been recorded in several medical books or handbooks, such as "Sheng Cao Yao Xing Bei Yao", "Ben Cao Qiu Yuan" and "Zhong Hua Ben Cao". It has been traditional employed for treating sore throat, stomach-ache, rheumatism and cancer. At present, there are limited studies on the evaluation of low-polarity extracts of roots in C. crassifolius. Consequently, the aim of this study was to evaluate the antitumor effect of the low-polarity extract of C. crassifolius root. Extracts were obtained by supercritical fluid extraction. The extracts were tested for antitumor effects in vitro on several cancer cell lines. A CCK-8 kit was used for further analysis of cell viability. A flow cytometer and propidium iodide staining were used to evaluate the cell cycle and apoptosis. Hoechst staining, JC-1 staining and the fluorescence probe DCFH-DA were used to evaluate apoptotic cells. Molecular mechanisms of action were analyzed by quantitative RT‒PCR and Western blotting. Immunohistochemistry was used for the evaluation of xenograft tumors in male BALB/c mice. Finally, molecular docking was employed to predict the bond between the desired bioactive compound and molecular targets. Eleven diterpenoids were isolated from low-polarity C. crassifolius root extracts. Among the compounds, chettaphanin II showed the strongest activity (IC 50 = 8.58 μM) against A549 cells. Evaluation of cell viability and the cell cycle showed that Chettaphanin II reduced A549 cell proliferation and induced G2/M-phase arrest. Chttaphanin II significantly induced apoptosis in A549 cells, which was related to the level of apoptosis-related proteins. The growth of tumor tissue was significantly inhibited by chettaphanin II in experiments performed on naked mice. The antitumor mechanism of chettaphanin II is that it can obstruct the mTOR/PI3K/Akt signaling pathway in A549 cells. Molecular docking established that chettaphanin II could bind to the active sites of Bcl-2 and Bax. Taken together, the natural diterpenoid chettaphanin II was identified as the major antitumor active component, and its potential for developing anticancer therapies was demonstrated for the first time by antiproliferation evaluation in vitro and in vivo. [Display omitted] • Eleven diterpenoids were obtained from the SFE extract of C. crassifolius roots. • Chettaphanin II showed the strongest antitumor activity against A549 cells. • Chettaphanin II inhibited A549 cell proliferation and arrested cells in G2/M-phase. • Chettaphanin II induced A549 cell apoptosis by inhibiting PI3K/AKT/mTOR pathway. • Chettaphanin II significantly inhibited the growth of tumor tissue in nude mice. [ABSTRACT FROM AUTHOR]

• A new anthrahydrazone ligand (9-THA) and its three metal complexes were synthesized. • The tested cancer cell lines were most sensitive to the Cu(II) complex, 9-THA-Cu. • 9-THA-Cu could bind with DNA in an intercalative mode by its planar structure. • The Cu(II) center play a key role to exert anticancer activity and induce apoptosis. In the present study, we synthesized and extensively characterized a novel ligand, 9-THA, based on 9-benzothiazolanthrahydrazone, along with its three corresponding transition metal complexes: 9-THA-Co (1), 9-THA-Ni (2), and 9-THA-Cu (3). The crystallographic analysis revealed distinct coordination geometries - six-coordinate for 9-THA-Co and 9-THA-Ni, binding three and two 9-THA ligands, respectively, and four-coordinate for 9-THA-Cu, binding one 9-THA ligand. In vitro anticancer screening demonstrated that 9-THA-Cu exhibited significant growth inhibition in HeLa-229, NCI-H460, and SK-OV-3 cancer cells with IC 50 values of 12.10 ± 0.54, 12.12 ± 0.58, and 17.65 ± 0.66 μM, respectively. Moreover, it displayed comparable cytotoxicity to cisplatin on HL-7702 normal liver cells. In contrast, 9-THA and 9-THA-Co/9-THA-Ni did not exhibit significant growth inhibition in the tested cancer cells, suggesting that Cu(II) played a pivotal role in its anticancer mechanism. Further investigation revealed the intercalative DNA binding mode of 9-THA-Cu by UV–Vis and fluorescent spectral analyses. It also exhibited competitive binding with two typical DNA intercalators, Gel-red (GR) and ethidium bromide (EB). Cell cycle and cell apoptosis experiments indicated that 9-THA-Cu at a concentration of 22 μM could induce cell cycle arrest in the S phase in 40 % of HeLa-229 cancer cells. Simultaneously, it induced 33.2 % apoptosis in HeLa-229 cells, suggesting that 9-THA-Cu may employ multiple mechanisms to exert its anticancer effects. [Display omitted] [ABSTRACT FROM AUTHOR]