Four novel betulinic acid (BA) derivatives modified at the C-3 position were prepared by the Mitsunobu reaction and subsequently evaluated for antitumor activity against four common cancer cell lines in vitro. The results from the MTT assay revealed that the four tested compounds showed remarkable cytotoxic activity against four cancer cell lines, much better than BA. Western blotting results indicated that the four compounds, especially compound 2c , caused a significant up-regulation expression of the caspase-12 in CT26 cell. Our results showed that configuration inversions of chiral C-3 of BA could also produce BA derivatives with potent antitumor activity.
Yan Liu,Zhuofeng Ke,Kwok Yiu Wu,Shuwen Liu,Wen-Hua Chen,Shibo Jiang,Zhi-Hong Jiang
Graphical Stopping HIV in its tracks! A series of betulinic acid–polyphenol conjugates were synthesized, with the aid of rational design by docking simulation, as novel HIV-1 fusion/entry inhibitors targeting gp41. These amphiphilic conjugates cooperatively interact with hydrophobic and hydrogen-bonding areas in the groove of the gp41 NHR trimeric coiled coil, demonstrating a promising strategy for the discovery of HIV-1 fusion/entry inhibitor binding to these two crucial pockets. Exploration of potent inhibitors of the HIV-1 gp41 fusion core formation is a promising strategy to discover small-molecule HIV-1 entry inhibitors for the treatment of HIV-1 infection. In this paper, a series of novel betulinic acid–polyphenol conjugates was designed, guided by molecular modeling of the binding of betulinic acid (BA) and phenolic galloyl/caffeoyl groups in the groove on the gp41 N-terminal heptad repeat (NHR) trimeric coiled coil. These conjugates were synthesized via conjugation of galloyl and caffeoyl groups with BA at the C-28 position. Their inhibitory activities of HIV gp41 six-helix bundle (6-HB) formation between the NHR peptide N36 and the C-terminal heptad repeat (CHR) peptide C34 were evaluated with size-exclusion HPLC. Conjugates bearing a galloyl group were found to exhibit four to sixfold higher inhibitory activities than that of parent compound BA, suggesting that they may be exploitable as HIV-1 fusion/entry inhibitors targeting gp41. The docking study on BA and its derivatives suggests that hydrophobic and hydrogen-bonding pockets exist in the groove of the gp41 NHR trimeric coiled coil and that a potent inhibitor should have amphiphilic structures to cooperatively interact with both pockets. This possibility was explored by incorporating both lipophilic and hydrophilic groups into the conjugates in a well-defined orientation to bind with both pockets in the gp41 NHR-trimer.
危险品化学品经营许可证（带存储）