134 resultados para preliminary discovery
Resumo:
A novel trypsin inhibitor termed BATI was purified to homogeneity from the skin extracts of toad Bufo andrewsi by successive ion-exchange, gel-filtration and reverse-phase chromatography. BATI is basic single chain glycoprotein, with apparent molecular weight of 22 kDa in SDS-PAGE. BATI is a thermal stable competitive inhibitor and effectively inhibits trypsin's catalytic activity on peptide substrate with the inhibitor constant (K-i) value of 14 nM and shows no inhibitory effect on chymotrypsin, thrombin and elastase. The N-terminal sequence of BATI is EKDSITD, which shows no similarity with other known trypsin inhibitors. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
Ten dibenzofurans were synthesized and evaluated as human immunodeficiency virus (HIV)-1 inhibitors in vitro for the first time. Among these compounds, compounds 1, 6, 7 and 8 demonstrated significant anti-HIV-1 activity. Especially compound 1 showed the
Resumo:
Ten single benzyl phenyl ethers were synthesized and evaluated as human immunodeficiency virus-1 (HIV-1) inhibitors in vitro for the first time. Among these compounds, especially 4-nitrobenzyl phenyl ether (3h) exhibited the highest anti-HIV-1 activity wi
Resumo:
To search for compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, ten 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline sulfonates (4a-j) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Some compounds demonstrated anti-HIV-1 activity, especially 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-ethylbenzenesulfonate (4g) and 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-chlorobenzenesulfonate (41) showed the more potent anti-HIV-1 activity with 50% effective concentration (EC50) values of 2.59 and 4.01 mu g/ml, and therapeutic index (TI) values of 31.77 and 24.51, respectively.
Resumo:
The authors thank Peng Shi, Scott Groom, and two anonymous reviewers for helpful comments. This work was supported by grants from the National Basic Research Program of China (973 Program, 2007CB411600), National Natural Science Foundation of China, and Bureau of Science and Technology of Yunnan Province (to Y.-P.Z.).
Resumo:
In this paper the habitat structure and ecology of Presbytis francoisi and Presbytis leucocephalus are compared. Observations were made of the two langur species in areas of southwest Guangxi province in which the langurs occur but are not sympatric. The results showed that the habitat of P. leucocephalus differs from that of P. francoisi and that the habitat in western areas was different from that in eastern areas in terms of vegetation and other criteria. P. francoisi was limited in its distribution to localities at higher altitudes, in contrast to P. leucocephalus. This may be due to human activities such as crop cultivation and logging. With respect to its activity pattern, P. leucocephalus spent 51.8% of its day in the trees and 48.2% on the rocky substrate. The results of this study suggest that Presbytis may best be regarded as a semiarboreal form.
Resumo:
Feeding and vocal behaviours of wild black gibbons (Hylobates concolor) were observed from 1987 to 1989 in south-western Yunnan, notably H. concolor jingdongensis at Mt. Wuliang (24-degrees 18-42'N, 100-degrees 30-50'E) in the early spring of 1989. 12 plant species were observed to have been eaten by the gibbons; these included tree species, lianas and epiphytes. Approximately 21 % of feeding time was devoted to eating fruits, 61 % to leaf buds and shoots, 7 % to flowers and 11 % to leaves. The gibbons preferred fruits to leaves even though they commonly ate leaves. In this study, the morning songs (duet and solo), reponsive (territorial) songs, alarm calls and communication calls were recorded. The gibbons sang their morning songs mainly in the early morning, with a single bout lasting more than 10 min on average. The singing of a group would trigger other groups, and all groups in an area tended to sing sequentially. The morning duet song bout was dominated by an adult male. The male emitted booms, aa notes, early multimodulated figures, intermediate multimodulated figures and codas, the latter occurring only in duets following the female's great call. The female uttered great calls and abortive great calls. The subadults or juveniles also took part in the morning songs. Lone males were heard to utter solos which lasted longer than the duets of the pairs.