A polyether-based imidazolium ionic liquid functionalized salen Al complex displays high efficiency and reusability as a homogeneous, single-component and multi-functional catalyst for the cycloaddition of CO2 to epoxides under mild conditions.

This review is devoted to highlighting main achievements in the development of cascade radical cyclization of radical acceptors for the synthesis of carbo- and heterocycles.

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To better understand the dynamic regulation of optimality in metabolic networks under perturbed conditions, we reconstruct the energetic-metabolic network in mammalian myocardia using dynamic flux balance analysis (DFBA). Additionally, we modified the optimal objective from the maximization of ATP production to the minimal fluctuation of the profile of metabolite concentration under ischemic conditions, extending the hypothesis of original minimization of metabolic adjustment to create a composite modeling approach called M-DFBA. The simulation results are more consistent with experimental data than are those of the DFBA model, particularly the retentive predominant contribution of fatty acid to oxidative ATP synthesis, the exact mechanism of which has not been elucidated and seems to be unpredictable by the DFBA model. These results suggest that the systemic states of metabolic networks do not always remain optimal, but may become suboptimal when a transient perturbation occurs. This finding supports the relevance of our hypothesis and could contribute to the further exploration of the underlying mechanism of dynamic regulation in metabolic networks.

We studied the robustness of photosynthetic metabolism in the chloroplasts of C3 plants under drought stress and at high CO2 concentration conditions by using a method called Minimization of Metabolic Adjustment Dynamic Flux Balance Analysis (M DFBA). Photosynthetic metabolism in the chloroplasts of C3 plants applies highly cooperative regulation to minimize the fluctuation of metabolite concentration profiles in the face of transient perturbations. Our work suggests that highly cooperative regulation assures the robustness of the biological system and that there is closer cooperation under perturbation conditions than under normal conditions. This results in minimizing fluctuations in the profiles of metabolite concentrations, which is the key to maintaining a system's function. Our methods help in understanding such phenomena and the mechanisms of robustness for complex metabolic networks in dynamic processes.climate extremes ͉ environmental stress ͉ flux balance ͉ metabolic control ͉ metabolomics A dvances in metabolomics technologies provide adequate data to make it possible to simulate the cell's metabolic networks as coherent systems (1). Approaches to analyzing the properties of such systems, such as Metabolic Control Analysis (MCA) and Flux Balance Analysis (FBA), provide means to assess the robustness of metabolic systems in compensating for perturbations (2, 3). FBA and Minimization of Metabolic Adjustment (MOMA) have been applied to study the robustness of biochemical pathways in the steady state (4-7). FBA can give the optimal value of the state of a homeostatic system, which we assume is the one acquired through the evolutionary process. To improve on FBA, the MOMA method has been designed to analyze metabolic networks under perturbations based on the hypothesis that perturbed metabolic fluxes undergo a minimum redistribution. It has been found that in some aspects MOMA is closer than FBA in predicting the result of inserting a mutation into a metabolic network (5,8,9). Under perturbed conditions, metabolic networks reach a new state through dynamic adjustment. To investigate these dynamics, Dynamic Flux Balance Analysis (DFBA) has been developed on the basis of dynamic optimal control theory (10). DFBA can incorporate kinetic information and has been applied successfully to simulate the diauxic growth of Escherichia coli. We developed an approach called Minimization of Metabolic Adjustment Dynamic Flux Balance Analysis (M DFBA), which is a DFBA method modified by extending the MOMA hypothesis (11). M DFBA has been used to model myocardial energy metabolism. We found that under ischemic conditions, the myocardium does not maximize the rate of ATP production as it does under normal conditions, but rather minimizes the fluctuation of the profile of metabolite concentrations (12). Even without complete system parameters, these methods can find the optimal state of a system or process by searching for the optimal solution using stoichiometric information for the reactions concerned. An objective functio...

MicroRNAs (miRNAs) are a cluster of short non-coding RNAs playing critical roles in human cancers. miR-187 was recently found to be a novel cancer-related microRNA. However, the expression and function of miR-187 in cervical cancer have not been investigated. In this study, we found that miR-187 level was decreased in cervical cancer tissues and cell lines. Patients with low level of miR-187 had significantly decreased rate of overall survival (OS) and progression-free survival (DFS). miR-187 overexpression inhibited proliferation and promoted apoptosis of cervical cancer cells, whereas miR-187 knockdown promoted proliferation and inhibited apoptosis of cervical cancer cells. Forced expression of miR-187 inhibited the subcutaneous growth of cervical cancer cells in nude mice. Furthermore, FGF9 was found to be the downstream target of miR-187 in cervical cancer cells. Importantly, targeting FGF9 was required for miR-187 exerting its tumor suppressive roles in cervical cancer cells.

A highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water, using formic acid as a reductant.

This review is devoted to highlighting the main achievements in the development of methodologies for the synthesis of isoxazolines.