Abdigupta8947

Twenty cultivars were categorized into four species, and the most appropriate discriminative marker m/z value for identifying each cultivar was selected statistically. Components extracted based on DI-EI-MS analyses could be used to construct a model to predict ATL cell bioactivity. These data suggest that the novel DI-EI-MS metabolomics method is suitable for identifying species of natural materials and predicting their pharmacologic activity. This approach could enhance public health by facilitating evaluations of pharmacologic activity and functionality, leading to the elimination of counterfeit products.Here the author describes the tumor-selective delivery of a fluorescence photosensitizing agent and an antitumor agent, based on the polymer effect of an N-(2-hydroxypropyl)methacrylamide (HPMA) based copolymer, by utilizing the enhanced permeability and retention (EPR) effect seen in solid tumors. Firstly, the tumor distribution of the photosensitizer, zinc-protoporphyrin IX (ZnPP), was significantly increased by conjugation with the HPMA polymer (P-ZnPP). The P-ZnPP suppressed tumor growth by local generation of cytotoxic singlet oxygen, and the tumor tissue was visualized by fluorescence upon light irradiation. Subsequently, a two-step mechanism for tumor selectivity was observed for the cytotoxic anthracycline, pirarubicin (THP), which conjugated the HPMA-based copolymer via a hydrazone bond (P-THP). The EPR-dependent accumulation of P-THP and the tumor-selective release of THP in the tumor tissues led to highly tumor-selective toxicity. Rapid cell uptake of THP compared to other anthracyclines, and deeper P-THP penetration of the tumor cell spheroid were attributed to the superior antitumor activity of P-THP. The molecular weight of P-THP affected its antitumor activity; oligomeric P-THP derivatives with higher molecular weights, DP-THP and SP-THP, showed even higher antitumor activity. P-THP was effective for both implanted tumor and autochthonous tumor models. These results indicate that nano-sized anticancer drugs based on polymer effect are promising clinical therapeutics.The central nervous system (CNS) is segregated from the circulating blood and peripheral tissues by endothelial and epithelial barriers. To overcome refractory CNS diseases, it is important to understand the membrane transport systems of drugs and the endogenous compounds that relate to the pathogenesis of CNS diseases at these barriers. The endothelial barrier in the brain is the blood-brain barrier (BBB). selleckchem Our studies clarified the efflux transport of prostaglandin E2 (PGE2), a modulator of neural excitation and inflammatory responses, across the BBB via plasma membrane transporters such as organic anion transporter 3 (Oat3) and multidrug resistance-associated protein 4 (Mrp4). This efflux transport was attenuated by peripheral inflammation or cerebral treatment with neuroexcitatory l-glutamate, suggesting that BBB-mediated PGE2 elimination was altered under several pathological conditions. We also examined excitatory amino acid transporter (EAAT) 1 and 3 as l-glutamate efflux transporters of the inner blood-retinal barrier (BRB) and blood-cerebrospinal barrier. It was considered that these efflux membrane transporters participated in the homeostasis of neuroexcitatory and neuroinflammatory responses in the brain and retina. Moreover, we identified connexin 43 (Cx43) hemichannels as a new membrane transport system that is activated under pathological conditions and recognizes several monocarboxylate drugs, such as valproate. As it is expected that the action of these membrane transporters across the CNS barriers is of great importance in understanding the pathology of various neuroexcitatory diseases, our studies should contribute to the establishment of therapeutic strategies for refractory CNS diseases.This article describes our stereoselective and site-selective chemical methods for exploiting cationic heterocycles as electron-withdrawing groups (EWGs). We envisioned that the phosphoramide N-H proton of a pyridyl phosphoramide 3 would be activated by the cationic pyridinium moiety that is formed upon protonation. The resulting imide-like N-H proton and the acidic pyridinium proton of the pyridinium phosphoramide 3⋅HX cooperate together, making 3⋅HX a highly acidic dual Brønsted acid. The catalytic ability of 3⋅HX was demonstrated in the development of the first asymmetric Diels-Alder reaction between 1-amide dienes and maleimides. Focusing on the activation of N-bromosuccinimide (NBS) because of its structural similarity to maleimides, the enantioselective bromolactonization of trisubstituted olefinic acids was accomplished utilizing pyridyl phosphoramide 3f as a Brønsted base catalyst bearing an acidic N-H proton. Lastly, our strategy for the site-selective acylation of polyol compounds is described. In our system, a pyridine aldoxime ester 10, used as a mild acylating reagent, was activated by a catalytic amount of Lewis acid via the inductive effect of the cationic pyridinium moiety. The resulting metal complex preferentially attracted the alcohol with a Lewis basic site, thereby facilitating selective acylation via a template effect. This metal-template-driven strategy allowed for the site-selective acylation of diverse α-hydroxyamides, including unprotected N-glycolyl aminosugars.In basic pharmaceutical sciences to achieve drug development, research on the efficient chemical synthesis of small molecules having cyclic skeletons is important. We have been engaged in the development of artificial catalysts for asymmetric ring formation reactions that exclusively synthesize right-handed or left-handed cyclic compounds and have achieved the construction of optically active cyclic skeletons using our original catalysts. The synthesis of biologically active compounds was facilitated through six-membered ring construction by Diels-Alder reaction of Danishefsky diene; however, no asymmetric variant of the reaction has been achieved. We approached this unresolved issue using multi-coordinated lanthanide metals. A new chiral lanthanide catalyst was developed, and the catalytic asymmetric Diels-Alder reaction of Danishefsky diene was realized for the first time. By modifying the chemical structure of Danishefsky diene, we applied the lanthanide catalyst to the syntheses of polycyclic compounds and biologically active compounds.