Design, synthesis, cytocidal activity and estrogen receptor α affinity of doxorubicin conjugates at 16α-position of estrogen for site-specific treatment of estrogen receptor positive breast cancer
摘要:
Doxorubicin (DOX) is an important medicine for the treatment of breast cancer, which is the most frequently diagnosed and the most lethal cancer in women worldwide. However, the clinical use of DOX is impeded by serious toxic effects such as cardiomyopathy and congestive heart failure. Covalently linking DOX to estrogen to selectively deliver the drug to estrogen receptor-positive (Er) cancer tissues is one of the strategies under investigation for improving the efficacy and decreasing the cardiac toxicity of DOX. However, conjugation of drug performed until now was at 3- or 17-position of estrogen, which is not ideal since the hydroxyl groups at this position are important for receptor binding affinity. In this study, we designed, prepared and evaluated in vitro the first estrogen-doxorubicin conjugates at 16 alpha-position of estradiol termed E-DOXs (8a-d). DOX was conjugated using a 3-9 carbon atoms alkylamide linking arm. E-DOXs were prepared from estrone using a seven-step procedure to afford the desired conjugates in low to moderate yields. The antiproliferative activities of the E-DOX 8a conjugate through a 3-carbon spacer chain on ER+ MCF7 and HT-29 are in the micromolar range while inactive on M21 and the ER- MDA-MB-231 cells (>50 mu M). Compound 8a exhibits a selectivity ratio (ER+/ER- cell lines) of >3.5. Compounds 8b-8d bearing alkylamide linking arms ranging from 5 to 9 carbon atoms were inactive at the concentrations tested (>50 mu M). Interestingly, compounds 8a-8c exhibited affinity for the estrogen receptor alpha (ER alpha) in the nanomolar range (72-100 nM) whereas compound 8d exhibited no affinity at concentrations up to 215 nM. These results indicate that a short alkylamide spacer is required to maintain both antiproliferative activity toward ER+ MCF7 and affinity for the ER alpha of the E-DOX conjugates. Compound 8a is potentially a promising conjugate to target ER. breast cancer and might be useful also for the design of more potent E-DOX conjugates. (C) 2012 Elsevier Inc. All rights reserved.
Design, synthesis, cytocidal activity and estrogen receptor α affinity of doxorubicin conjugates at 16α-position of estrogen for site-specific treatment of estrogen receptor positive breast cancer
摘要:
Doxorubicin (DOX) is an important medicine for the treatment of breast cancer, which is the most frequently diagnosed and the most lethal cancer in women worldwide. However, the clinical use of DOX is impeded by serious toxic effects such as cardiomyopathy and congestive heart failure. Covalently linking DOX to estrogen to selectively deliver the drug to estrogen receptor-positive (Er) cancer tissues is one of the strategies under investigation for improving the efficacy and decreasing the cardiac toxicity of DOX. However, conjugation of drug performed until now was at 3- or 17-position of estrogen, which is not ideal since the hydroxyl groups at this position are important for receptor binding affinity. In this study, we designed, prepared and evaluated in vitro the first estrogen-doxorubicin conjugates at 16 alpha-position of estradiol termed E-DOXs (8a-d). DOX was conjugated using a 3-9 carbon atoms alkylamide linking arm. E-DOXs were prepared from estrone using a seven-step procedure to afford the desired conjugates in low to moderate yields. The antiproliferative activities of the E-DOX 8a conjugate through a 3-carbon spacer chain on ER+ MCF7 and HT-29 are in the micromolar range while inactive on M21 and the ER- MDA-MB-231 cells (>50 mu M). Compound 8a exhibits a selectivity ratio (ER+/ER- cell lines) of >3.5. Compounds 8b-8d bearing alkylamide linking arms ranging from 5 to 9 carbon atoms were inactive at the concentrations tested (>50 mu M). Interestingly, compounds 8a-8c exhibited affinity for the estrogen receptor alpha (ER alpha) in the nanomolar range (72-100 nM) whereas compound 8d exhibited no affinity at concentrations up to 215 nM. These results indicate that a short alkylamide spacer is required to maintain both antiproliferative activity toward ER+ MCF7 and affinity for the ER alpha of the E-DOX conjugates. Compound 8a is potentially a promising conjugate to target ER. breast cancer and might be useful also for the design of more potent E-DOX conjugates. (C) 2012 Elsevier Inc. All rights reserved.
Among other aspects, provided herein are multi-armed polymer conjugates comprising an alkanoate-linker, compositions comprising such conjugates, and related methods of making and administering the same. Methods of treatment employing such conjugates and related uses are also provided. The conjugates are prepared with high drug loading efficiencies.
Lessons in Strain and Stability: Enantioselective Synthesis of (+)‐[5]‐Ladderanoic Acid
作者:Erin N. Hancock、Erin L. Kuker、Dean J. Tantillo、M. Kevin Brown
DOI:10.1002/anie.201910901
日期:2020.1.2
The synthesis of structurally complex and highly strained natural products provides unique challenges and unexpected opportunities for the development of new reactions and strategies. Herein, the synthesis of (+)-[5]-ladderanoic acid is reported. En route to the target, unusual and unexpected strain release driven transformations were uncovered. This occurrence required a drastic revision of the synthetic