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A series of 4-(piperazin-1-yl)-7H-pyrrolo[2,3-d]pyrimidine derivatives was synthesized and evaluated as Akt inhibitors by optimization of a weak screening lead (1). Typically, compounds 5q and 5t significantly improved the Akt1 inhibitory potency with IC50 values of 18.0 and 21.3 nM, respectively, with desirable antiproliferative effect against the cell lines LNCaP and PC-3. The inhibitors 5q and 5t might serve as lead compounds for further exploration of Akt inhibitors as anticancer agents.

A HBSP has been designed as a novel bifunctional enzyme model with SOD and GPx activity by host/guest-directed self-assembly of MnTPyP-M-Ad and 6-Te-diCD. The structure of the host/guest complex was elucidated by (1) H NMR spectra, and the HBSP was characterized by SEM, DLS and measurement of catalytic properties. In the bifunctional enzyme model, the Mn(III) porphyrins act as efficient SOD active sites and the tellurol moieties endow GPx activity. The SOD-like activity (IC(50) ) of this new supramolecular catalyst was found to be 1.05 × 10(-7) M, which corresponds to 2.82% of the activity of the native SOD enzyme. Besides this, the hyperbranched supramolecular polymer also shows a higher GPx activity (ν(0 ) = 21.7 × 10(-6) M · min(-1) ) than other supramolecular enzyme models.

The selenoenzyme glutathione peroxidase has received increased attention as one of the antioxidative enzymes exerting important biological roles in living bodies. Over the past decades, much effort has been invested to mimic its catalytic behavior for understanding enzymatic catalytic mechanisms and also for developing potential medicines. A great number of artificial GPxs, ranging from small molecular compounds to macromolecular ones, have been designed and prepared by combining the concept of recognition and catalysis using chemical, biological and supramolecular strategies. In this article, we specify the development of artificial GPxs based on macromolecules as scaffolds, and discuss the power of reduced models in studying the bio-catalytic nature of selenoenzymes.

To construct an efficient GPx mimic, a novel method for preparing polymer-based vesicles carrying GPx-active sites was developed. A series of block copolymers loaded with recognition and catalytic sites were synthesized based on polystyrene-block-poly[tri(ethylene glycol) methyl ether acrylate]s (PS-PMEO(3) MAs). By altering the molar ratio of the functional copolymers, vesicles with GPx activity were obtained by self-assembly of these functional copolymers through blending. The optimum GPx mimic constructed by the blending process exhibited high catalytic activity and acted as a real catalyst with typical saturation kinetics behavior. The method may be of benefit for designing other enzyme mimics and may cast a light on constructing other biologically related functional nanoparticles.

A temperature-sensitive block copolymer (PAAm-b-PNIPAAm-Te) with a glutathione peroxidase-like active site was synthesized via ATRP. As a new glutathione peroxidase (GPx) mimic, it displays typical saturation kinetic behaviors and high catalytic activity. More importantly, the catalytic activity of the polymer can be well modulated by changing the temperature. The experiments proved that a change in the self-assembly structure of the polymer plays a key role for the modulation of catalytic activity. As a contrast, another block copolymer, PAAm-Te-b-PNIPAAm, was synthesized. In comparison with PAAm-b-PNIPAAm-Te, the different temperature dependent catalytic behavior seen further indicates that the micellar structure plays an important role in modulating the catalytic activity of the smart enzyme model.

Using native cassava starch as raw materials, carboxymethyl starch (CMS) was prepared by ethanol solvent method under the ultrasound-microwave synergistic interaction. And the structure of CMS was characterized employing Fourier transform infrared (FTIR) spectrometer, scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analyzer. Typically, the optimal synthesis conditions for the preparation process confirmed by orthogonal experiment L18 (61 × 36) were shown as follows: the ultrasonic treatment temperature was fixed to 35°C and two steps alkalization was employed; the ultrasonic time was 40 min before alkalizing and the ultrasonic power was 220 W; the amount of sodium hydroxide was 8.8 g, the microwave alkalization time was 2 min; the amount of monochloroacetic acid was 11.34 g; the amount of 95% (v/v) ethanol was 70 mL; the microwave etherification time was 3 min. The degree of substitution of prepared CMS was 1.089 ± 0.041, which was increased 30.4% compared with the prepared sample without ultrasound-microwave synergistic treatment. FTIR results showed that the strong COO characteristic absorption peaks of the stretching vibration were observed at 1613 and 1421 cm−1, which proved that the carboxymethylation of cassava starch was occurred. SEM results suggested that there were many cracks and dents on CMS granules; and, XRD results indicated that the carboxymethylation of starch occurred both in amorphous region and crystalline region, the noticeable damage of crystalline region by carboxymethylation was observed. Thermogravimetric analysis (TG) and derivative TG showed that thermal stability of CMS changed better compared with native starch. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40906.