Synthesis and antitumor activity of 20 (S)-camptothecin derivatives: A-ring modified and 7, 10-disubstituted camptothecins.

~31%

~%

~48%

~%

~%

~%

~%

~39%

~%

~12%

~9%

~12%

~%

~%

~56%

~%

~%

~25%

~22%

~77%

~31%

~75%

~%

~%

~%

~%

~%

~%

~%

~%

~%