Synthesis and anticancer activity of novel fused pyrimidine hybrids of myrrhanone C, a bicyclic triterpene of Commiphora mukul gum resin

Myrrhanone C [8(R)-3-oxo-8-hydroxypolypoda-13E,17E,21-triene], a bicyclic triterpene isolated from the gum resin of Commiphora mukul, has been chemically transformed to synthesize a series of ten novel pyrimidine hybrids in good to excellent yields. The synthesized compounds (2-22) were evaluated for their anticancer potential against a panel of six cancer cell lines, namely A-549 (lung), Hela (cervical), MCF-7 (breast), ACHN (renal), Colo-205 (colon) and B-16 (mouse melanoma) by employing the MTT assay. In general, the synthesized compounds showed significant anticancer activity against all the cancer cell lines tested. Interestingly, the pyrimidine hybrids 18 and 19 showed good activity against the A-549, MCF-7, B-16, Colo-205 and ACHN cancer cell lines with values between 7.7-37.8 M. Most significantly, compounds 19 (IC: 7.7 M) and 18 (IC: 9.5 M) showed about five- and six-fold enhanced activities, respectively, compared to the parent myrrhanone C (1) against A-549 cell line. Flow cytometric analysis revealed that compounds 18 and 19 induced apoptosis in A-549 cells and arrested the cell growth in the G0/G1 phase.