Structure and activity relationship of monogalactosyl diacylglycerols, which selectively inhibited in vitro mammalian replicative DNA polymerase activity and human cancer cell growth

Abstract

The glycoglycerolipid, monogalactosyl diacylglycerol (MGDG), containing two α-linolenic acids (C18:3), was isolated from bitter melon as a potent and selective inhibitor of mammalian DNA polymerase (pol) species such as pols α, γ, δ, and ε with IC 50 values of 17.6–37.2 μM. This MGDG also suppressed the growth of six human cancer cell lines, although normal human cell lines were not affected. This compound (i.e., MGDG-C18:3-C18:3) was a stronger inhibitor than both MGDG-C18:1-C18:0 and MGDG-C18:0-C18:0. In this study, we discussed the structure–function relationship in the selective inhibition of mammalian replicative pols and human cancer cell proliferation by MGDGs.