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Abstract: Here, we report a three-component coupling reaction approach between an aldehyde, an allyloxyamine, and a maleimide toward isoquinoline derivatives. At first, an oxime O-allylic ether, prepared by dehydrative condensation of the aldehyde and the allyloxyamine, was reacted with the maleimide in the presence of a Pd2+ species. The cycloadduct obtained was then subjected to the Heck cyclization employing a Pd0 species to give thermodynamically stable diastereomer of isoquinoline derivatives selectively in 25–78% yields. [Copyright &y& Elsevier]

Abstract: 2-Oxo-1,2-ethylenedioxy (2-OED) functionality has been prepared on a soluble MPEG polymer and solid (HM resin and Lanterns) supports as platforms for discovery of drug-like small molecules. The functionality is cleaved either by Yb(OTf)3 or TMSCHN2 in MeOH, or by various amines to release small molecules synthesized on the platform in good yield. Application of these platforms aiming for discovery of potent agonists for growth hormone secretagogue is reported by using the Ugi four-component coupling reaction. [Copyright &y& Elsevier]

In this article, we performed a comparative study to investigate the performance of methods for detecting emerging research fronts. Three types of citation network, co-citation, bibliographic coupling, and direct citation, were tested in three research domains, gallium nitride (GaN), complex network (CNW), and carbon nanotube (CNT). Three types of citation network were constructed for each research domain, and the papers in those domains were divided into clusters to detect the research front. We evaluated the performance of each type of citation network in detecting a research front by using the following measures of papers in the cluster: visibility, measured by normalized cluster size, speed, measured by average publication year, and topological relevance, measured by density. Direct citation, which could detect large and young emerging clusters earlier, shows the best performance in detecting a research front, and co-citation shows the worst. Additionally, in direct citation networks, the clustering coefficient was the largest, which suggests that the content similarity of papers connected by direct citations is the greatest and that direct citation networks have the least risk of missing emerging research domains because core papers are included in the largest component. [ABSTRACT FROM AUTHOR]

Nucleotide sequences of ribosomal RNA maturase (matK) regions in chloroplast (cp) DNA were determined to assess genetic diversity within cultivated teas. One hundred-eighteen cultivated teas from India, Bangladesh, Myanmar, Thailand, Laos, Vietnam, China and Japan were analyzed. The 1,230 aligned nucleotide sequences of the matK DNA of the cultivated teas showed 13 variations. These variations in the matK defined 10 different types (CJ, AA, AB, AC, AD, AE, IC, IM, TM and TV). By nucleotide alignment analysis, the matK nucleotide sequences in the samples from Japan and eastern China and from tea estates in India and Bangladesh were divided into CJ and AA types. On the other hand, the matK in the teas of Yunnan in China and southeast Asian countries shared 9 types (AA, AB, AC, AD, AE, IC, IM, TM and TV). The matK sequences of southeastern cultivars were fragmented into smaller population clusters as compared to the eastern samples. In addition, these matK types were classified into three groups. The CJ, AA and AB types were placed in the group Camellia sinensis (var. sinensis and var. assamica). The AC, IC, IM, TM and TV types had strong affinity to C. taliensis and C. irrawadiensis. AE and AD types with 6-base insertions belonged to a third group. Results of the matK nucleotide sequence analysis indicated that the cultivated teas of India, Bangladesh, eastern China and Japan belonged to the group of C. sinensis. The cultivated teas in the estates of Southeast Asia region also belonged to C. sinensis. However, the native cultivars in Myanmar and southern China had a genetic similarity to C. taliensis and C. irrawadiensis. The native cultivars of Thailand and Vietnam will be associated with morphologically close taxa. In this study, we demonstrated that members of C. irrawadiensis and C. taliensis are popular cultivars found widely in the southeastern Asia. Tea cultivars of the AC, AD, AE, IC, IM, TM and TV types merit to be conserved for use as sources of desirable genes. [ABSTRACT FROM AUTHOR]

Goniodomin A is a phycotoxin produced by the dinoflagellates Alexandrium hiranoi (formerly Goniodoma pseudogoniaulax ) and Alexandrium monilatum. This polyether macrolide exerts a potent antifungal effect and disturbs the actomyosin ATPase activity and the F-actin meshwork in diverse cell types. Goniodomin B is a fused acetal isomer isolated with goniodomin A with unknown activity. Histopathological changes induced by goniodomin A postulated hepatocytes as target cells. In this study both compounds induce a time and concentration dependent fall in the viability of Clone 9 rat hepatocytes. Furthermore, for both compounds, primary rat hepatocytes are almost 10 folds less sensitive than Clone 9 cells. Goniodomin A is highly effective in the nanomolar range while micromolar concentrations of goniodomin B are necessary to observe cytoxicity. Additionally, goniodomin A induced a significant increase in the F-actin and decrease in the G-actin content of Clone 9 cells but did not change the actin of primary cultured hepatocytes. However, goniodomin B could not exert significant alterations in the cytoskeleton of neither cell type. Futhermore goniodomin A as well as goniodomin B are cytotoxic to excitable cells. Both analogues triggered a time dependent decrease on viability in BE(2)-M17 human neuroblastoma cells. In this cell model goniodomin A increased the intracellular calcium and depolarized cells. We conclude that goniodomins A and B are biologically active molecules in hepatocytes and also in excitable cells BE(2)-M17. However, the analogue goniodomin B, whose activity is described in this work for the first time, is a much less potent compound. [ABSTRACT FROM AUTHOR]

We analyze a topological structure of networks formed according to the entries and trackbacks in the blogosphere, which is a collection of weblog articles. The analysis is performed based on community extraction, network visualization and keyword analysis. It is shown that the large-scale structure of the blogosphere has a globally sparse, but locally dense structure. The entries in a community yield a dense structure while the trackbacks that interconnect communities are sparse. The visualized results show sparkling-firework-like patterns. We then attempt to characterize the communities using a tf-idf technique. It is found that specific topics are discussed in each community. These results will help us to identify the communities in which certain specific topics discussed and to detect trends in the blogosphere. [ABSTRACT FROM AUTHOR]