Antitumor-active Betulinic Derivatives
benefit the potency. The results also demonstrated that
the existence of a structural constraint such as benzyl,
biphenyl and phenyl at C-28 is favorable to the inhibitory
activity. The obtained structure–activity relationships of
C-28 position have also confirmed the results from pre-
vious comparative molecular field analysis (CoMFA), in
which the contour maps illustrated that bulky and/or
electron-donating groups at C-28 would be favorable for
activity (20).
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compounds exhibited more potent antiproliferative effect
than parent compound HBA, in particular compounds 13e
and 14a were about four- to sevenfold more potent than
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and 14a was validated in H22 liver cancer and B16 mela-
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Conflict of Interest
The authors declare they have no conflict of interests.
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The project was funded by the National Natural Science
Foundation of China (No. 81273377), Key Laboratory for
the Chemistry and Molecular Engineering of Medicinal
Resources (Guangxi Normal University), Ministry of Educa-
tion of China (No. CMEMR2013-B05), the Project for
Research and Innovation of Graduates in Universities of Ji-
angsu Province (CXLX13_306) and the Project Program of
State Key Laboratory of Natural Medicines, China Pharma-
ceutical University (No. SKLNMZZCX201404).
Chem Biol Drug Des 2015
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