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11.
Masao Shiozaki Takuya Tashiro Hiroyuki Koshino Tomokuni Shigeura Hiroshi Watarai Masaru Taniguchi Kenji Mori 《Tetrahedron》2013
RCAI-80 is one of the ester analogs of KRN7000 (α-galactosylceramide). This compound released mainly T helper 2 (Th2) cytokines, such as IL-4 rather than T helper 1 (Th1) cytokines, such as IFNγ from the invariant natural killer T (iNKT) cells. In addition, it has been known that some of the hydroxylated derivatives of KRN7000 make the cytokine secretion bias to Th2 by decreasing the IFNγ production to almost zero. This time, the three compounds having these two characteristic properties, namely an ester group and also some extra hydroxy groups existing on the ester side chain and/or on the 2-acyloxy-3,4-dihydroxyoctadecyl main chain of RCAI-80, were synthesized to examine the biological activities. As a result, it was found that these compounds made the cytokine secretion skew to Th2. Therefore, their effectiveness for experimental autoimmune encephalomyelitis (EAE) was examined. It was recognized that one of them showed moderate suppression of EAE symptom. 相似文献
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8,5'-Aminimino bridging in the guanosine series using 5'-O-tosyl (1) and 5'-O-mesyl derivatives (2) of 2',3'-O-isopropylidene-8-bromoguanosine (5) and hydrazine gave N3,5'-cyclized product 3 and the N5,5'-cyclonucleoside of 4-carboxyhydrazido-5-amino-2-bromoimidazole 4. To exclude the N3,5'-cyclization through ionization in the base moiety, a N2-dimethylaminomethylidene-N1-methoxymethylene derivative 7 was synthesized from 5 through the N2-protected compound 6. 7 was converted into the N2-dimethylaminomethy analogue 8, which with hydrazine yielded first the N2-deprotected form of 8 (9). 8 or 9 with hydrazine under forcing conditions gave an 8,5'-aminimino-N1-methox derivative 10. Oxidation of 10 with sodium metaperiodate or sodium nitrite yielded 8,5'-imino-N1-methoxymethyleneguanosine (11a) and 8,5'-imino-N1-methoxymethylenexanthosine derivative 11b, respectively. 11a was deprotected to 8,5'-imino-N1-methoxymethyleneguanosine 12. 相似文献
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The structures of the dihydro derivatives of 5,6-diaryl-1,2,4-triazines and of the products from the title reactions have been reassigned as 5,6-diaryl-2,5-dihydro-1,2,4-triazines (a-g) and 2,6-diaryl-4-methyl-5-substituted-1,8-bis-methoxycarbonyl-3,4,7-triaza-bicyclo[3.3.0]octa-2,7-dienes (a-g), respectively. 相似文献
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Tomokuni Takahashi 《Geometriae Dedicata》2011,154(1):183-206
We classify the certain type of relative quadric hypersurfaces of 3-dimensional projective space bundles over a projective
line or an elliptic curve whose fiber is the direct product of 2 projective lines. 相似文献