Cytotoxic effect of carbohydrate derivatives of digitoxigenin involves modulation of plasma membrane Ca -ATPase.

Cardiac glycosides, such as digoxin and digitoxin, are compounds that interact with Na /K -ATPase to induce anti-neoplastic effects; however, these cardiac glycosides have narrow therapeutic index. Thus, semi-synthetic analogs of digitoxin with modifications in the sugar moiety has been shown to be an interesting approach to obtain more selective and more effective analogs than the parent natural product. Therefore, the aim of this study was to assess the cytotoxic potential of novel digitoxigenin derivatives, digitoxigenin-α-L-rhamno-pyranoside (1) and digitoxigenin-α-L-amiceto-pyranoside (2), in cervical carcinoma cells (HeLa) and human diploid lung fibroblasts (Wi-26-VA4).

Synthesis of Modular Building Blocks using Glycosyl Phosphate Donors for the Construction of Asymmetric N-Glycans.

Glycosyl phosphates are known as versatile donors for the synthesis of complex oligosaccharides both chemically and enzymatically. Herein, we report the stereoselective construction of modular building blocks for the synthesis of N-glycan using glycosyl phosphates as donors. We have synthesized four trisaccharide building blocks with orthogonal protecting groups, namely, Manβ2GlcNAc(OAc)β6GlcNAc (), Manβ2GlcNAc-β6GlcNAc(OAc) (), Manβ2GlcNAc(OAc)β4GlcNAc () and Manβ2GlcNAcβ4GlcNAc(OAc) () for further selective elongation using glycosyltransferases.

asymmetric synthesis of the mezzettiaside family of natural products via the iterative use of a dual B-/Pd-catalyzed glycosylation.

The first synthesis of any and all members of the mezzettiaside family of natural products has been achieved. The reported synthesis features the iterative use of the Taylor catalyst in a dual nucleophilic boron/electrophilic palladium catalyzed regioselective glycosylation. In addition, the approach utilizes atomless protecting groups and the minimal use of protecting groups (2 chloroacetates for the synthesis of 10 natural products).

Structure activity relationship study of Mezzettiasides natural products and their four new disaccharide analogues for anticancer/antibacterial activity.

Ten members of the mezzettiaside family of natural products were synthesized and evaluated for anticancer and antibacterial activity. Complete anticancer (H460) and antibacterial () activities for the ten natural products and four new analogues were found. Comparison to the cleistrioside and cleistetroside classes of natural products were made.

Digitoxin analogues with improved anticytomegalovirus activity.

Cardiac glycosides are potent inhibitors of cancer cell growth and possess antiviral activities at nanomolar concentrations. In this study we evaluated the anticytomegalovirus (CMV) activity of digitoxin and several of its analogues. We show that sugar type and sugar length attached to the steroid core structure affects its anticytomegalovirus activity.