Anti-cancer activity of phytochemicals extracted from Urtica pilulifera on Hela cells.

Urtica pilulifera is effective against cancer cell growth but its bioactive compounds and the mechanism of action behind its effect are still to be clarified. This study evaluated the anticancer activity of compounds extracted from Urtica pilulifera leaves against cervical cancer cells. The cytotoxic effect of water, methanol and hexane extracts of Urtica pilulifera leaves was assessed by MTT assay. The most potent extract was fractionated by column chromatography and its anticancer activity was evaluated. GC-MS was used to identify the chemical components of the different fractions. Western blotting analysis was used to determine the level of specific apoptotic and cell cycle protein markers. Data showed that the hexanic extract exhibits the most potent cytotoxicity against Hela cells. Fraction 4 of the hexanic extract showed the most potent antiproliferative effect against Hela cells. GC-MS analysis showed that the most prominent compound in fraction 4 is phytol. Fraction 4 treatment induced cell cycle arrest and intrinsic apoptosis in Hela cells as evident by the increasing levels of p21, p53, PARP cleavage and active caspase 9. These findings reveal the ability of U. pilulifera hexanic extract to induce cell cycle arrest and apoptosis in cervical cancer cells.

Design, Synthesis and Biological Evaluation of Novel Pyrazolo[1,2,4]triazolopyrimidine Derivatives as Potential Anticancer Agents.

Three novel pyrazolo-[4,3-e][1,2,4]triazolopyrimidine derivatives (1, 2, and 3) were designed, synthesized, and evaluated for their in vitro biological activity. All three compounds exhibited different levels of cytotoxicity against cervical and breast cancer cell lines. However, compound 1 showed the best antiproliferative activity against all tested tumor cell lines, including HCC1937 and HeLa cells, which express high levels of wild-type epidermal growth factor receptor (EGFR). Western blot analyses demonstrated that compound 1 inhibited the activation of EGFR, protein kinase B (Akt), and extracellular signal-regulated kinase (Erk)1/2 in breast and cervical cancer cells at concentrations of 7 and 11 µM, respectively. The results from docking experiments with EGFR suggested the binding of compound 1 at the ATP binding site of EGFR. Furthermore, the crystal structure of compound 3 (7-(4-bromophenyl)-9-(pyridin-4-yl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine) was determined by single crystal X-ray analysis. Our work represents a promising starting point for the development of a new series of compounds targeting EGFR.

Homoleptic organometallic anions of Ti, Zr, Hf, and Nb.

Reactions of C(6)H(5)Li and 4-CH(3)C(6)H(4)Li with halides of Ti, Ir, Hf, and Nb lead to the formation of homoleptic organometallic anions of these metals. Owing to their thermal instability and their sensitivity towards H(2) O and O(2) , these compounds are characterized by single-crystal structure determinations at low temperature, whereas other physical data could only be obtained occasionally. Three pentacoordinate complex anions [Ti(C(6)H(5))(5)](-), [Ti(4-CH(3)C(6)H(4))(5)](-), and [Zr(C(6)H(5))(5)](-) have square-pyramidal structures that display only slight deviations from the ideal geometry, in contrast to the already known structures of [Ti(CH(5))(5)](-). The hexacoordinate complex anions [Zr(C(6)H(5))(6)](2-), [Zr(4-CH(3)C(6)H(4))(6)](2-), [Nb(C(6)H(5))(6)](2-), and [Nb(4-CH(3)C(6)H(4))(6)](2-) all have trigonal-prismatic structures, in accord with the known hexamethyl complex dianions. In contrast, the hexacoordinate complex anion [Hf(C(6)H(5))(6)](2)(-) has an octahedral or close to octahedral structure, in contrast to the known trigonal-prismatic structures of [Ta(C(6)H(5))(6)](-) and [Ta(4-CH(3)C(6)H(4))(6) (-). A qualitative explanation for this structural variability is given.

Tungsten(VI) and tungsten(V) fluoride complexes.

WF(6) reacts with phosphines R(3)P forming 1:1 compounds. With R=P(CH(3))(3) the coordination around the tungsten atom is capped trigonal prismatic, with R=P(CH(3))(2)C(6)H(5) the coordination is capped octahedral, as established by single-crystal structure determinations: [(CH(3))(3)P--WF(6)]: a=752.5(21), b=945.7(24), c=629.8(18) pm. beta=110.36(13) degrees , space group Cm, Z=2; [(CH(3))(2)(C(6)H(5))P--WF(6)]: a=762.2(2), b=1123.5(2), c=2647.5(6) pm, space group Pbca, Z=8. [(CF(3)CH(2))(2)N--WF(5)] reacts smoothly with P(C(6)H(5))(3) forming known P(C(6)H(5))(3)(F)(2) and [(CF(3)CH(2))(2)N--WF(4)--P(C(6)H(5))(3)], a stable, green, molecular species, identified among other methods with an crystal structure determination: a=914.9(1), b=956.0(1), c=1449.8(2) pm, alpha=7.642(4), beta=81.648(3), gamma=81.519 degrees , space group P$\bar 1$, Z=2.

Inversion dimers dominate the crystal packing in the structure of trimethyl citrate (trimethyl 2-hy-droxy-propane-1,2,3-tri-carboxyl-ate).

Trimethyl citrate, C9H14O7 (systematic name: trimethyl 2-hy-droxy-propane-1,2,3-tri-carboxyl-ate), 2, was prepared by the esterification of citric acid and methanol in the presence of thionyl chloride at 273 K. The bond lengths and angles in 2 compare closely with those observed in citric acid. The C-C bonds adjacent to the terminal carboxyl groups are significantly shorter than those around the central C atom. The central carboxyl-ate group and the hy-droxy group occur in the normal planar arrangement with an r.m.s. deviation of 0.0171 Šfrom the mean plane involving all six atoms in the central unit. The crystal structure is almost completely dominated by the formation of inversion dimers through an O-H⋯O hydrogen bond, together with an extensive array of weaker C-H⋯O contacts. These generate a three-dimensional network structure with mol-ecules stacked along the c-axis direction.