Chemoenzymatic synthesis of sulfoquinovosylmonoacylglycerols (SQMG) as anti-tumor-promoters

During our search for new glycoglycerolipids active in cancer chemoprevention, in recent years we have synthesized a number of esters of 2-O-beta-D-glycosylglycerols in which the length, shape, number and position of the acyl chain, and the type of sugar (alphaand beta glucose or galactose) were varied. These compounds were found to be very active in inhibiting the tumor-promoting activity of the phorbol ester TPA both in in vitro and in in vivo tests, being such activities mainly influenced by the changes of the acyl chains length. Sulfoquinovosylacylglycerols are acylated sulfoglycolipids in which sulfoquinovose (6-deoxy-6-sulfo-glucose) is alpha-linked to the sn-3 position of glycerol. These compounds exhibit noteworthy biological activities, that make them very attractive for their use in cancer therapy. Here we report the synthesis of 6’-sulfo-derivatives (SQMG) based on the skeleton of 2-O-beta-D-glucosylglycerol to which previously synthesized biologically active glucoglycerolipid analogues are related. A chemoenzymatic strategy has been used to selectively insert the proper chemical functionalities (i.e. acyl chain) at the desired position of glucosylglycerol to obtain the target compounds. Their potential as anti-tumor-promoters will be also discussed.