Novel myricetin derivatives: Design, synthesis and anticancer activity.

Telomere and telomerase were closely related to occurrence and development of some cancers. To enhance ability of myricetin moiety for inhibiting telomerase, we designed a series of novel myricetin derivatives based on reasonable analysis. The telomerase inhibition assay showed that compound 6d displayed the most potent inhibitory activity with IC50 value of 0.91 µM. The anticancer activity assay showed that 6d exhibited high activity against human breast cells MDA-MB-231. The docking simulation of compound 6d was performed to get the probable binding model, the results demonstrated that the furan ring inserted into the active site deeply and had hydrophobic interactions with residues of Phe 568, Pro 627, four methoxy groups had hydrophobic interactions with residues of Phe 568, Pro 627, Lys 902, Val 904 and Pro 929. Western blot results showed that expression of p65 and TERT protein was clearly down-regulated by compound 6d. These data support further studies for the rational design of more efficient p65 and TERT modulators.

Preliminary evaluation of the in vitro efficacy of 1, 2-di (quinazolin-4-yl) diselane against SiHa cervical cancer cells.

Cervical cancer is one the most common malignancies among females. In recent years, its incidence rate has shown a rising trend in some countries so that development of anticancer drugs for cervical cancer is an urgent priority. In our recent anticancer drug discovery screen, 1, 2-di (quinazolin-4-yl)diselane (LG003) was found to possess wide spectrum anticancer efficacy. In the present work, the in vitro anticancer activity of LG003 was evaluated in the SiHa cervical cancer cell line. Compared with commercial anticancer drugs 10-hydroxycamptothecin, epirubicin hydrochloride, taxol and oxaliplatin, LG003 showed better anticancer activity. Furthermore, inhibition effects were time- and dose-dependent. Morphological observation exhibited LG003 treatment results in apoptosis like shrinking and blebbing, and cell membrane damage. Lactate dehydrogenase release assay revealed that LG003 exerts such effects in SiHa cells through a physiology pathway rather than cytotoxicity, which suggests that title compound LG003 can be a potential candidate agent for cervical cancer.

Synthesis and anticancer activities of 4-(4-substituted piperazin)-5,6,7-trialkoxy quinazoline derivatives.

A series of 4-(4-substituted piperazin)-5,6,7-trialkoxy quinazoline was prepared by conventional heating methods. Among these compounds, the crystal structure of compound 10o (CCDC: 916922) was determined by X-ray crystallography. Bioassay results showed that most target compounds had certain inhibition activities against proliferation of tumor cells, and some compounds even had good broad-spectrum inhibition activities. The ethoxyl series of compounds possessed higher inhibition activities against tumor cells than the methoxyl series of compounds. Bioactivity tests showed that the IC50 values of compound 10s against PC3, MGC803, A375, and A549 cells were 1.8, 2.8, 1.3, and 2.9 µΜ, respectively, which were much higher than those of commercial gefitinib (7.2, 7.6, 7.2, and 9.8 µM, respectively). Conversely, the IC50 values of compound 10s were very low against NH3T3, indicating only weak effect on normal cells as also proven by lactate dehydrogenase and acridine orange/ethidium bromide staining. Analyses of cell configuration and cell cycle revealed that compound 10s possibly caused cells to remain at G0/G1 phase by inhibiting cell proliferation for 24 h. Compound 10s also inhibited the phosphorylation of ERK1/2 and P38 with obvious concentration dependence. Thus, these compounds can inhibit the proliferation of A549 cells through the interruption of ERK1/2 and P38signaling pathways.

[Antibacterial mechanism of sulforaphane on Escherichia coli].

OBJECTIVE: To investigate the antibacterial mechanism of sulforaphaneon (SFN) on Escherichia coli. METHODS: To determine membrane penetrability, changes of SDS-PAGE protein spectra, soluble protein and alkaline phosphatase and reducing sugar were determined. Cellular nucleic acid synthesis was detected by 4, 6- diamidino-2-phenylindole (DAPI) staining assay. RESULTS: SFN affected the membrane permeability of Escherichia coli. Ions and small molecules could leak out of the cells. But it did not destroy the membrane integrity directly. After 16 hours of treatment with SFN, the total contents of intracellular and extracellular proteins decreased by 42.5% and 17.6%, respectively, while the quantity of DNA and RNA reduced by 34.8% and 48.5% respectively. CONCLUSION: SFN can affect cell membrane permeability, material and energy metabolism and inhibit the synthesis of nucleic acid and protein.