In search of a dopamine D2 and serotonin 5-HT3 receptors dual antagonist as a potential broad antiemetic agent, a number of benzamides were prepared from 4-amino-5-chloro-2-methoxybenzoic acid derivatives and 6-amino-1,4-dialkylhexahydro-1,4-diazepines and evaluated for their binding affinity for the dopamine D2 and the serotonin 5-HT3 receptors using rat brain synaptic and rat cortical membranes, respectively. From the results of both in vitro receptor binding and in vivo biological assays for the dopamine D2 receptor, 1-ethyl-4-methylhexahydro-1,4-diazepine ring was selected as an optimum amine moiety. Introduction of one methyl group on the nitrogen atom at the 4-position and/or modification of the substituent at the 5-position of the 4-amino-5-chloro-2-methoxybenzoyl moiety caused a marked increase in the dopamine D2 receptor binding affinity along with a potent 5-HT3 receptor binding affinity. Among the compounds, 5-chloro-N-(1-ethyl-4-methylhexahydro-1,4-diazepin-6-yl)-2-methoxy-4-methylaminobenzamide (82), 5-bromo (110), and 5-iodo (112) analogues exhibited a much higher affinity for the dopamine D2 receptor than that of metoclopramide (IC50=17.5-61.0 nM vs. 483 nM). In particular, 82 showed a potent antagonistic activity for both receptors in vivo tests. Optical resolution of the racemate 82 brought about a dramatic change in the pharmacological profile with the (R)-enantiomer exhibiting a strong affinity for both the dopamine D2 and the 5-HT3 receptors, while the corresponding (S)-enantiomer had a potent and selective serotonin 5-HT3 receptor binding affinity. 相似文献
In search for potent and selective beta3-adrenergic receptor (beta3-AR) agonists as potential drugs for the treatment of type II diabetes and obesity, a novel series of 1-(3-chlorophenyl)-2-aminoethanol derivatives were prepared and evaluated for their biological activity at human beta1-, beta2-, and beta3-ARs and rat beta3-AR expressed in Chinese hamster ovary (CHO) cells. Replacement of the right-hand side (RHS, benzene ring) in the 'first generation' beta3-AR agonists BRL 37344 and CL 316243 with a 1H-indole ring gave compound 31 with unique pharmacological properties among beta3-AR agonists. Initial in vitro assays showed that 31 possesses modest rat and human beta3-ARs agonistic activity. Introduction of various substituent into the indole nucleus of 31 afforded a number of compounds with good beta3-ARs agonistic activity. In particular, 90 having a carboxylic acid functionality at the 7-position of the indole nucleus showed the most potent human beta3-AR agonistic activity. Finally, optical resolution of 90 led to the identification of the most promising compound, [3-[(2R)-[[(2R)-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]-1H-indol-7-yloxy]acetic acid (96, AJ-9677). This compound exhibited potent human beta3-AR agonistic activity (EC50=0.062 nM, IA=116%) with 210- and 103-fold selectivity over human beta2-AR and beta1-AR, respectively. Compound 96 also exhibited potent rat beta3-AR agonistic activity (EC50=0.016 nM, IA=110%). Moreover, repeated oral administration of 96 inhibited body weight gain and significantly decreased glucose, insulin, free fatty acid, and triglyceride concentrations in plasma in KK-Ay/Ta mice. On the basis of this pharmacological profile, 96 entered clinical development as a drug for the treatment of type II diabetes and obesity. 相似文献
Five pairs of diastereoisomeric dioxetanes, cis- and trans-2a–2e, were synthesized. These dioxetanes underwent intramolecular charge-transfer-induced decomposition with accompanying emission of orange light in TBAF in DMSO (system A) as a complete homogeneous system and in [K(18C6)]+t-BuO− in PhH–THF (system B) as a sterically anisotropic environment. Maximum wavelength (λmaxCTICL) of chemiluminescence did not vary practically with the triggering system. The λmaxCTICL was little affected also by substituents on the upper-Nap of dioxetanes 2, nor by the difference in their stereochemistry, namely, cis- or trans-isomer. On the other hand, chemiluminescent efficiency was found to split up depending on stereochemistry of 2. Dioxetane 2b bearing a methoxycarbonyl group on the upper-Nap gave significantly weak light, while its free carboxylic acid analog 2c afforded light effectively. 相似文献
We present a simple proof of the nonexistence of monotonic solutions derived from the Kuramoto-Sivashinsky equation. Although
our method restricts the range of parameters, it has the advantage of applicability to other equations, which includes a model
of dendritic growth of needle crystals.
Sunto In questo lavoro, presentiamo una semplice dimostrazione di non esistenza di soluzioni monotone per l’equazione di Kuramoto-Sivashinsky.
Sebbene il nostro metodo restringa il range dei parametri, esso ha il vantaggio di essere applicabile anche ad equazioni aventi
interesse fisico quali descriventi un modello locale di solidificazione.
In this paper, we are concerned with a new algorithm for multichain finite state Markov decision processes which finds an
average optimal policy through the decomposition of the state space into some communicating classes and a transient class.
For each communicating class, a relatively optimal policy is found, which is used to find an optimal policy by applying the
value iteration algorithm. Using a pattern matrix determining the behaviour pattern of the decision process, the decomposition
of the state space is effectively done, so that the proposed algorithm simplifies the structured one given by the excellent
Leizarowitz’s paper (Math Oper Res 28:553–586, 2003). Also, a numerical example is given to comprehend the algorithm. 相似文献
In this paper, applying an interval arithmetic analysis, we consider the average case of controlled Markov set-chains, whose process allows for fluctuating transition matrices at each step in time. We introduce a v-step contractive property for the average case, under which a Pareto optimal periodic policy is characterized as a maximal solution of optimality equation. Also, in the class of stationary policies, the behavior of the expected reward over T-horizon as T approaches ∞ is investigated and the left- and right-hand side optimality equations are given, by which a Pareto optimal stationary policy is found. As a numerical example, the Taxicab problem is considered. 相似文献
Near‐infrared (NIR) imaging techniques have attracted significant attention for biological and medicinal applications due to the ability of NIR to penetrate deeply into tissues. However, there are very few stable, activatable molecular probes that can utilize NIR light in the wavelength range beyond 800 nm. Herein, we report a new activatable NIR system for photoacoustic imaging based on tautomeric benziphthalocyanines (BPcs). We found that the existence of a free hydroxyl group is crucial for NIR absorption of BPcs. Synthesized water‐soluble hydroxy BPcs exhibited high photostability and no fluorescence, which are desirable features for photoacoustic imaging. We synthesized BPcs in which the free hydroxyl group was masked by an esterase‐labile or an H2O2‐labile group. The photoacoustic signals of these hydroxy‐masked BPcs were increased upon NIR excitation at 880 nm in the presence of esterase or H2O2, respectively. These are rare examples of activatable probes utilizing NIR light at around 900 nm. 相似文献
Summary: Polymer nanospheres are synthesized by free‐radical dispersion copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDM) with a methacryloyl‐terminated polystyrene (PS‐MC) macromonomer in cyclohexane. Such polymer nanospheres are stabilized sterically with polystyrene (PS)‐grafted chains in cyclohexane at temperatures greater than 34 °C (the Θ temperature for PS). Ordered microporous surface films are constructed by casting these core‐shell‐type nanospheres from hot cyclohexane solution at 20 °C. The results indicate the possibility of fixation or encapsulation of functional materials after microporous patterning of the core‐shell‐type nanospheres.
SEM photograph of a vertical section of a hexagonal micropore film obtained here. 相似文献