Synthesis of Gambogic Acid Oxidative Analogues and Their Dimension Quantity Structure-activity Relationship Analysis

35,40-Dihydroxyl-6-methoxyl-gambogic acid methyl ester(1),9,10-dihydroxyl-6-methoxyl-gambogic acid methyl ester(2) and 2-deisohexylene-2-(2-formyl)ethyl-6-methoxyl-gambogic acid methyl ester(3) were first synthesized.And their antitumour activities on several cancer lines were tested.Meanwhile via Tripos Sci QSAR software calculation the QSAR equation explains the relationship between activity and structure with 2D QSAR method,and the biological activities are closely related to polarity volume ratio,the absolute value of the total charge,valence connectivity indexes and molecular volume.Our research can provide some guide meaning for the following research on studies of gambogic acid derivates.