The improved 3 step preparation of a key antitumor agent, 7 ethyl 10 hydroxycamptothecin(SN 38), which consists of ethylation, oxidation and photo chemical rearrangement, is described. The proposed reaction mech...The improved 3 step preparation of a key antitumor agent, 7 ethyl 10 hydroxycamptothecin(SN 38), which consists of ethylation, oxidation and photo chemical rearrangement, is described. The proposed reaction mechanism is also discussed.展开更多
The reduction-responsive disulfide bonds have been widely used as bioactive linkages to facilitate a rapid release of anticancer drugs into tumor cells.However,the activation can be hindered by the kinetics of the thi...The reduction-responsive disulfide bonds have been widely used as bioactive linkages to facilitate a rapid release of anticancer drugs into tumor cells.However,the activation can be hindered by the kinetics of the thiol-disulfide exchange reactions.Supplementing with an additional reductant is a promising strategy to further boost drug release.Herein,inspired by the specific absorption mechanism of triglyceride fat,structured lipid-mimetic oral prodrugs of 7-ethyl-10-hydroxycamptothecin(SN38)were designed to improve intestinal permeability and bypass the first-pass effect.SN38 prodrugs were prepared into lipid formulations that could self-emulsify into nano-sized particles after entering the gastrointestinal tract.Surprisingly,we found that the oral bioavailability of the prodrug lipid formulation could be up to 2.69-fold higher than that of the parent SN38,indicating an effective oral delivery.In addition,the reduction-responsive disulfide bond was used as a linker,and ascorbic acid(ASC)was coadministrated to further promote the efficient release of SN38 from the prodrug.ASC enhanced the oral antitumor effect of the reduction-responsive oral prodrug and exhibited good safety.In summary,the combination of a structured lipid-mimetic prodrug and ASC was firstly demonstrated to boost the oral chemotherapy effect of the difficult-for-oral chemotherapeutics.展开更多
文摘The improved 3 step preparation of a key antitumor agent, 7 ethyl 10 hydroxycamptothecin(SN 38), which consists of ethylation, oxidation and photo chemical rearrangement, is described. The proposed reaction mechanism is also discussed.
基金supported by the National Key Research and Development Program of China(No.2021YFA0909900)the National Natural Science Foundation of China(Nos.82073777,82104109,and 82173766).
文摘The reduction-responsive disulfide bonds have been widely used as bioactive linkages to facilitate a rapid release of anticancer drugs into tumor cells.However,the activation can be hindered by the kinetics of the thiol-disulfide exchange reactions.Supplementing with an additional reductant is a promising strategy to further boost drug release.Herein,inspired by the specific absorption mechanism of triglyceride fat,structured lipid-mimetic oral prodrugs of 7-ethyl-10-hydroxycamptothecin(SN38)were designed to improve intestinal permeability and bypass the first-pass effect.SN38 prodrugs were prepared into lipid formulations that could self-emulsify into nano-sized particles after entering the gastrointestinal tract.Surprisingly,we found that the oral bioavailability of the prodrug lipid formulation could be up to 2.69-fold higher than that of the parent SN38,indicating an effective oral delivery.In addition,the reduction-responsive disulfide bond was used as a linker,and ascorbic acid(ASC)was coadministrated to further promote the efficient release of SN38 from the prodrug.ASC enhanced the oral antitumor effect of the reduction-responsive oral prodrug and exhibited good safety.In summary,the combination of a structured lipid-mimetic prodrug and ASC was firstly demonstrated to boost the oral chemotherapy effect of the difficult-for-oral chemotherapeutics.
